Elysium Technologies Private...

Elysium Technologies Private Limited Singapore | Madurai | Chennai | Trichy | Coimbatore | Ramnad

Pondicherry | Salem | Erode | Tirunelveli

http://www.elysiumtechnologies.com, [email protected]

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ETPL NT-001 Answering “What-If” Deployment and Configuration Questions With WISE: Techniques and Deployment Experience

ETPL NT-002 Complexity Analysis and Algorithm Design for Advance Bandwidth Scheduling in Dedicated Networks

ETPL NT-003 Diffusion Dynamics of Network Technologies With Bounded Rational Users: Aspiration-Based Learning

ETPL NT-004 Delay-Based Network Utility Maximization

ETPL NT-005 A Distributed Control Law for Load Balancing in Content Delivery Networks

ETPL NT-006 Efficient Algorithms for Neighbor Discovery in Wireless Networks

ETPL NT-007 Stochastic Game for Wireless Network Virtualization

ETPL NT-008 ABC: Adaptive Binary Cuttings for Multidimensional Packet Classification,

ETPL NT-009 A Utility Maximization Framework for Fair and Efficient Multicasting in Multicarrier Wireless Cellular Networks

ETPL NT-010 Achieving Efficient Flooding by Utilizing Link Correlation in Wireless Sensor Networks,

ETPL NT-011 Random Walks and Green's Function on Digraphs: A Framework for Estimating Wireless Transmission Costs

ETPL NT-012 "A Flexible Platform for Hardware-Aware Network Experiments and a Case Study on Wireless Network Coding

ETPL NT-013 Exploring the Design Space of Multichannel Peer-to-Peer Live Video Streaming Systems

ETPL NT-014 Secondary Spectrum Trading—Auction-Based Framework for Spectrum Allocation and Profit Sharing

ETPL NT-015 Towards Practical Communication in Byzantine-Resistant DHTs

ETPL NT-016 Semi-Random Backoff: Towards Resource Reservation for Channel Access in Wireless LANs

ETPL NT-017 Entry and Spectrum Sharing Scheme Selection in Femtocell Communications Markets

ETPL NT-018 On Replication Algorithm in P2P VoD,

ETPL NT-019 Back-Pressure-Based Packet-by-Packet Adaptive Routing in Communication Networks

ETPL NT-020 Scheduling in a Random Environment: Stability and Asymptotic Optimality

ETPL NT-021 An Empirical Interference Modeling for Link Reliability Assessment in Wireless Networks

ETPL NT-022 On Downlink Capacity of Cellular Data Networks With WLAN/WPAN Relays

ETPL NT-023 Centralized and Distributed Protocols for Tracker-Based Dynamic Swarm Management

ETPL NT-024 Localization of Wireless Sensor Networks in the Wild: Pursuit of Ranging Quality

ETPL NT-025 Control of Wireless Networks With Secrecy

ETPL NT-026 ICTCP: Incast Congestion Control for TCP in Data-Center Networks

ETPL NT-027 Context-Aware Nanoscale Modeling of Multicast Multihop Cellular Networks

ETPL NT-028 Moment-Based Spectral Analysis of Large-Scale Networks Using Local Structural Information

ETPL NT-029 Internet-Scale IPv4 Alias Resolution With MIDAR

ETPL NT-030 Time-Bounded Essential Localization for Wireless Sensor Networks

ETPL NT-031 Stability of FIPP -Cycles Under Dynamic Traffic in WDM Networks

ETPL NT-032 Cooperative Carrier Signaling: Harmonizing Coexisting WPAN and WLAN Devices

ETPL NT-033 Mobility Increases the Connectivity of Wireless Networks

ETPL NT-034 Topology Control for Effective Interference Cancellation in Multiuser MIMO Networks

ETPL NT-035 Distortion-Aware Scalable Video Streaming to Multinetwork Clients

ETPL NT-036 Combined Optimal Control of Activation and Transmission in Delay-Tolerant Networks

ETPL NT-037 A Low-Complexity Congestion Control and Scheduling Algorithm for Multihop Wireless















This study investigates the stability of fuzzy-model-based (FMB) control system, which is formed by a

Takagi-Sugeno (T-S) fuzzy model representing a non-linear plant and a fuzzy controller connected in a closed

loop. The proposed fuzzy controller considers a higher design flexibility that the premise membership

functions and the number of fuzzy rules are allowed to be not the same as those of the T-S fuzzy model. By

employing simple membership functions and a smaller number of fuzzy rules, the complexity of the fuzzy

controller can be reduced to facilitate its implementation. Based on the Lyapunov stability theory, a

membership-function-dependent (MFD) stability analysis is proposed to develop stability conditions in the

form of linear matrix inequalities (LMIs) to determine the system stability and facilitate the control synthesis.

The information of the membership functions is brought to the MFD LMI-basedstability conditions, which are

dedicated to the FMB controlsystem under consideration. It is thus the proposed MFDstability analysis result

is more relaxed compared with the existing membership-function-independent stability analysis results. A

simulation example is given to illustrate the effectiveness of the proposed approach.

ETPL

PE - 001

Linear matrix inequalities-based member ship function-dependent stability analysis for

non-parallel distributed compensation fuzzy-model-based control systems

This paper proposes a robust adaptive voltage control of three-phase voltage source inverter for a distributed

generation system in a standalone operation. First, the state-space model of the load-side inverter, which

considers the uncertainties of system parameters, is established. The proposed adaptive

voltage control technique combines an adaption control term and a state feedback control term. The former

compensates for system uncertainties, while the latter forces the error dynamics to converge to zero. In

addition, the proposed algorithm is easy to implement, but it is very robust to system uncertainties and sudden

load disturbances. In this paper, a stability analysis is also carried out to show the robustness of the closed-

loop controlsystem. The proposed control strategy guarantees excellent voltage regulation performance (i.e.,

fast transient response, zero steady-state error, and low THD) under various types of loads such as balanced

load, unbalanced load, and nonlinear load. The simulation and experimental results are presented under the

parameter uncertainties and are compared to the performances of the corresponding nonadaptive voltage

controller to validate the effectiveness of the proposed control scheme.

ETPL

PE - 002

A Three-Phase Inverter for a Standalone Distributed Generation System:

Adaptive Voltage Control Design and Stability Analysis








This paper investigates the stability of polynomial-fuzzy-model-based (PFMB) control system, which is

formed by a polynomial fuzzy model and a polynomial fuzzy controller connected in a closed loop. To

enhance the design flexibility, the number of rules and the shape of premise membership functions of the

polynomial fuzzy controller are considered to be chosen freely and are different from those of the polynomial

fuzzy model, however, which make the stabilityanalysis more difficult and potentially lead to

conservativestability analysis result. A sum-of-squares (SOS)-basedstability analysis approach using the

Lyapunov stabilitytheory is proposed to investigate the stability of the PFMBcontrol systems and synthesize

the polynomial fuzzy controller. To facilitate the stability analysis and relax thestability analysis result, the

property of the membership functions and the boundary information of the membership grades and premise

variables are taken into account in thestability analysis and incorporated into the SOS-

basedstability conditions. A simulation example is given to illustrate the effectiveness of the proposed

approach.

ETPL

PE - 003

Stability Analysis of Polynomial-Fuzzy-Model-BasedControl Systems With

Mismatched Premise Membership Functions

STATCOM can provide fast and efficient reactive power support to maintain power system voltage stability.

In the literature, various STATCOM control methods have been discussed including many applications of

proportional-integral (PI) controllers. However, these previous works obtain the PI gains via a trial-and-error

approach or extensive studies with a tradeoff of performance and applicability. Hence, control parameters for

the optimal performance at a given operating point may not be effective at a different operating point. This

paper proposes a newcontrol model based on adaptive PI control, which can self-adjust the control gains

during a disturbance such that the performance always matches a desired response, regardless of the change of

operating condition. Since the adjustment is autonomous, this gives the plug-and-play capability for

STATCOM operation. In the simulation test, the adaptive PIcontrol shows consistent excellence under various

operating conditions, such as different initial control gains, different load levels, change of transmission

network, consecutive disturbances, and a severe disturbance. In contrast, the conventional

STATCOM control with tuned, fixed PI gains usually perform fine in the original system, but may not

perform as efficient as the proposed control method when there is a change of system conditions.

ETPL

PE - 004

Adaptive PI Control of STATCOM for Voltage Regulation








Input-series-output-series (ISOS) connected dc-dc converters enable the utilization of low-voltage rating

switches in high-voltage-input and high-voltage-output applications that require galvanic isolation. To achieve

input or output power balance among all the constituent modules, a general control strategy eliminating the

use of input-voltage sharing (IVS) loops is proposed. The instability mechanism of independent output-voltage

sharing controlhas been investigated by using the Routh-Hurwitz criterion. From the same criterion,

a stability design method for the proposed control strategy has been developed. Detailed comparison of the

proposed control technique, voltage-mode IVS, and current-mode IVS control methods is made. In

comparison, the proposed control strategy has the same performance compared with current-mode

IVS control. Thecontrol system design is simplified by avoiding mandatory IVS loops which are needed for

IVS control. Both the steady-state and dynamic performance are improved with the proposed control strategy

in comparison with voltage-mode IVS control. Using the proposed control strategy, excellent input and output

power balance can be achieved for the ISOS connection during transient and steady-state conditions. The

proposed control strategy performance is validated by experimental results of a 960-W ISOS systemcomposed

of three two-transistor forward dc-dc converters.

ETPL

PE - 005

A General Control Strategy for Input-Series–Output-Series Modular DC–DC

Converters

This paper discusses the extension of electromechanical stability models of voltage source converter high

voltage direct current (VSC HVDC) to multi-terminal (MTDC) systems. The paper introduces a control model

with a cascaded DC voltage control at every converter that allows a two-terminal VSC HVDC system to cope

with converter outages. When extended to an MTDC system, the model naturally evolves into a master-slave

set-up with converters taking over the DC voltage control in case the DC voltage controlling converter fails. It

is shown that the model can be used to include a voltage droop control to share the power imbalance after a

contingency in the DC system amongst the converters in the system. Finally, the paper discusses two possible

model reductions, in line with the assumptions made in transient stability modeling. The control algorithms

and VSC HVDC systems have been implemented using both MatDyn, an open source MATLAB transient

stability program, as well as the commercial power system simulation package EUROSTAG.

ETPL

PE - 006

Modeling of Multi-Terminal VSC HVDC Systems With Distributed DC Voltage

Control








This paper presents a new control approach for enhancing the fault ridethrough capability of wind farms

connected to the grid through a voltage-source-converter-based high-voltage dc transmission line. A controlled

voltage drop in the wind farm collector grid is initiated upon the occurrence of fault in the high-voltage grid in

order to achieve fast power reduction. In the process, a dc voltage of defined magnitude and duration is

injected by the sending-end converter together with the voltage reduction to suppress the dc component of the

short-circuit current arising from the voltage reduction. As a result, the electrical and mechanical stress on the

wind turbines, especially on the DFIG-based units and their converters, are mitigated. Using a test network,

the improvement in the fault ridethrough capability of the system that can be achieved by employing the

proposed method has been demonstrated.

ETPL

PE - 007

Enhanced Voltage Drop Control by VSC–HVDC Systems for Improving Wind Farm

Fault Ridethrough Capability

In the experiments and practical applications in a high-speed railway, it is observed that the carrier frequency

of the sampled signal in a track circuit reader (TCR) is changed with train speed and goes beyond the upper

permissive range prescribed for a jointless track circuit (JTC) in some cases. This can directly affect the

availability of train target speed in train control systems and thus has an effect on the generation of the

distance-to-go profile. It not only reduces the safety and efficiency of train traveling but also limits the

improvement of train speed. To find the primary cause of the deviation in carrier frequency of the sampled

signal in TCR (CFSST), this paper models the track-to-train continuous information transmission process

using the transmission linetheory based on the structures and principles of JTC and TCR. Then, the relation

between the deviation in CFSST and the train speed is derived. Experimental results in high-speed railway

have verified the correctness of the analysis, and the study can provides a strong theoretical basis for

improving the safety level of railway traffic. Moreover, it can be a good reference for other countries where

the similar track circuits are applied.

ETPL

PE - 008

Study of the Track–Train Continuous InformationTransmission Process in a

High-Speed Railway








The past and recent investigations show that front time of switching overvoltage waveforms in Ultra High

Voltage (UHV) system of long distance transmission are mostly in long wave front time exceeding 1000μs.

The long front time of switching impulse voltage has been deviated from the critical front time. This paper is

involved with breakdown characteristics and external insulation design under long front switching impulse

voltage in UHV system. All the Tests were performed on an outdoor UHV test site at altitude of 2100 m,

China Southern Power Grid Co. Ltd. (CSG). Breakdown characteristics of rod-plane and actual size tower-

conductor in /spl l.chemo/800 kV UHV DC transmissionline are obtained under wide front time switching

impulse voltages from 100 to 2350 μs. From the comprehensive studies of such tests, it is proposed that U50 of

front time exceeding 1000 μs increases 20% compared with the results of standard switching impulse

(250/2500 μs) tests and standard deviations of U50 is 6% in UHV transmissionsystem. Finally, an air gap

insulation design procedure in conductor-tower of UHV transmission line at altitude of 0-2000 m is presented.

Long front time switching impulse strength of conductor-tower gap is proposed into selection by reference in

UHV transmission line insulation design.

ETPL

PE - 009

Long front time switching impulse tests of long air gap in UHV projects at

altitude of 2100 m

An efficient and well-established technology for powertransmission across long distances is high-voltage

direct current transmission (HVDC). However, HVDC is currently almost completely limited to peer-to-peer

connections or networks with peers situated closely to each other. This contribution introduces the flatness-

based design of a feed-forward control of HVDC transmission networks comprising two or more converter

stations. The resulting control concept allows for a flexible determination of the power distribution within the

network. Furthermore, effects such as power losses and delays due to wave propagation, which are related

especially to long transmission lines, can be easily considered. Numerical simulations for an example network

are included to prove the value of the results.

ETPL

PE - 010

Feed-Forward Control of an HVDC PowerTransmission Network








Droop control is the basic control method for load current sharing in dc microgrid applications. The

conventional dc droop control method is realized by linearly reducing the dc output voltage as the output

current increases. This method has two limitations. First, with the consideration of lineresistance in a droop-

controlled dc microgrid, since the output voltage of each converter cannot be exactly the same, the output

current sharing accuracy is degraded. Second, the dc-bus voltage deviation increases with the load due to the

droop action. In this paper, in order to improve the performance of the dc microgrid operation, a low-

bandwidth communication (LBC)-based improved droop control method is proposed. In contrast with the

conventional approach, the control system does not require a centralized secondary controller. Instead, it uses

local controllers and the LBC network to exchange information between converter units. The droop controller

is employed to achieve independent operation, and the average voltage and current controllers are used in each

converter to simultaneously enhance the current sharing accuracy and restore the dc bus voltage. All of the

controllers are realized locally, and the LBC system is only used for changing the values of the dc voltage and

current. Hence, a decentralized control scheme is accomplished. The simulation test based on

MATLAB/Simulink and the experimental validation based on a 2 × 2.2 kW prototype were implemented to

demonstrate the proposed approach.

ETPL

PE - 011

An Improved Droop Control Method for DC Microgrids Based on Low Bandwidth

Communication With DC Bus Voltage Restoration and Enhanced Current Sharing

Accuracy

An infinite source with series inductance is usually employed as a grid emulator in grid-connected distributed

generation systems. Thus, high capacitance of a transmission cable (i.e., underground cable) is too significant

to be neglected. As a result, the capacitance and inductance may cause system resonance, which, in turn,

challenges system stability. This paper takes offshore wind farm as an example to investigate the resonance

issues caused by the submarine transmission cable of the grid-connected generation system. Based on the

submarine cable model, a series of considerable resonant peaks is found in the open-loop transfer function of

the grid-connected system because of the high-order LC configuration. The resonant peaks are sensitive to the

system setup, which is clearly investigated. To overcome the resonances, this paper proposes a cascaded

notch-filter-based active damping method to guarantee a good system stability and robustness. Furthermore,

the proposed controller employs a proportional-resonant component to reduce the steady-state error of the

output current. The simulation and experimental results have validated the findings of resonances and the

effectiveness of the proposed controller.

ETPL

PE - 012

Resonance Issues and Damping Techniques for Grid-Connected Inverters With

Long Transmission Cable








This paper proposes a unique topology of voltage-fed high-frequency series load resonant inverter with a

lossless snubber capacitor and an auxiliary switched cell for induction heating appliances. The main objective

of this paper is to demonstrate how high power density can be achieved by including a switched capacitor cell

with the capacitor-clamped half-bridge zero voltage switching high-frequency inverter circuit using the PWM

control scheme. The operation principle of the proposed inverter circuit is based upon an asymmetrical duty

cycle pulsewidth modulated (PWM) control scheme. The operating performances of high-frequency ac

regulation and power conversion efficiency characteristics are shown through experiments with their soft-

switching operating ranges.

ETPL

PE - 013

High Power Density Series Resonant Inverter Using an Auxiliary Switched

Capacitor Cell for Induction Heating Applications

This paper develops a novel single-switch resonant power converter for renewable energy generation

applications. This circuit topology integrates a novel single-switch resonant inverter with zero-voltage

switching (ZVS) with an energy-blocking diode with zero-current switching (ZCS). The energy-blocking

diode with a direct-current output filter filters the output stage of the novel single-switch resonant inverter.

Only one active power switch is used for power energy conversion to reduce the cost of active power switches

and control circuits. The active power switch is controlled by pulsewidth modulation at a fixed switching

frequency and a constant duty cycle. When the resonant converter is operated at discontinuous conduction

mode, the inductor current through the resonant tank could achieve ZCS of the energy-blocking diode.

Accordingly, a high energy conversion efficiency is ensured. Operating principles are derived, and analyses

are carried out based on the equivalent circuits for the proposed power converter under different operating

modes. The operating principles of the converter were verified using a 32.4-W 70-kHz experimental

photovoltaic-powered load system. Given appropriately chosen circuit parameters, the active power switch can

be operated with ZVS, and a measured energy conversion efficiency of the proposed topology of 97.3% can be

achieved. Experimental results demonstrate a satisfactory performance of the proposed topology, which is

particularly suited to the energy conversion applications in renewable energy generation systems.

ETPL

PE - 014

A Novel Single-Switch Resonant Power Converter for Renewable Energy

Generation Applications








An architecture of multiple-integrated converter modules sharing an unfolding full-bridge inverter with a

pseudo dc link (MIPs) is proposed for grid-connected photovoltaic systems in this paper. The proposed

configuration can improve the power conversion, the control circuit complexity, and the cost competitiveness.

The proposed MIP is composed of distributed flyback dc-dc converters (DFCs) and an unfolding full-bridge

inverter with an ac filter. The DFCs can eliminate the shading effect by using the individual maximum power

point tracking. In conventional flyback-type single-phase utility-interactive inverters, discontinuous

conduction mode and boundary conduction mode are popular because of the inherent constant current-source

characteristics more desirable for grid connection and of the simple procedures for the controller design.

However, the operating mode suffers from a large current stress of the circuit components, which leads to the

low power efficiency. To avoid this, the DFCs operate under continuous conduction mode that allows reduced

current stresses and increased power efficiency, as well as low material cost. The current control loop of the

converters employs primary-side regulation contributing to improvement of dynamics as well as the cost

reduction significantly due to the elimination of the high-linearity photocoupler device. Development of a new

dc-current loop that maintains the level of dc-current injection into the grid within the levels stipulated by

IEEE 1547 will be dealt as well. The performance validation of the proposed design is confirmed by

experimental results of a 200-W hardware prototype.

ETPL

PE - 015

Analysis and Design of Grid-Connected Photovoltaic Systems With Multiple-

Integrated Converters and a Pseudo-DC-Link Inverter








This paper presents an advanced switching sequence for space-vector pulsewidth modulation (SV-PWM)-

based three level neutral-point clamped inverter. The developed scheme helps to reduce the number of

converter switching sequences, compared with the conventional SV-PWM strategy, and keeps the voltage

difference between the two dc-link capacitors at the desired voltage level. The developed test bench is utilized

for a permanent magnet synchronous machine (PMSM) drive for electric vehicle applications. The proposed

strategy is compared with the performance of a PI controller-based voltage balancing strategy. The proposed

control strategy is based on the nearest three-vector (N3V) scheme, with a hysteresis control of the dc-link

capacitor voltage difference. Conventional N3V scheme uses a higher number of switching sequences, which

makes the switching losses higher. In addition, these switching sequences are not same for all subsectors. This

makes the switching frequency to vary extensively. In the proposed control strategy, a reduced number of

switching sequences are used, and they are same for all subsectors. This makes the system operate with

constant switching frequency. Detailed simulation studies are performed to verify the performance of the

proposed control strategy. The performance-based test results are then compared with those of a PI controller-

based strategy. Experimental test results show significant improvement in the performance of the PMSM with

respect to dc-link capacitor voltage variation as well as wide speed and torque range of machine operation.

ETPL

PE - 016

DC-Link Voltage Balancing for a Three-Level Electric Vehicle Traction

Inverter Using an Innovative Switching Sequence Control Scheme

This paper presents neutral-point potential (NPP) balancing while maintaining low harmonic distortion using

optimal pulsewidth modulation (PWM) of a multilevel inverter for medium-voltage high-power industrial ac

drives. This method is applicable for five-level inverters or higher. A high performance of the machine is

observed experimentally at low-switching-frequency operation employing the proposed technique. In the past,

low distortion and optimal common-mode voltage at low-switching-frequency control have been reported

using proposed synchronous optimal PWM.

ETPL

PE - 017

Neutral-Point Potential Balancing Using Synchronous Optimal Pulsewidth Modulation

of Multilevel Inverters in Medium-Voltage High-Power AC Drives








A simplified space vector modulation (SVM) technique is proposed for the seven-level cascaded H-bridge

(CHB) inverter. It is based on decomposing the seven-level space vector hexagon into a number of two-level

space vector hexagons. The presented technique significantly reduces the calculation time and efforts involved

in the SVM of a seven-level inverter; without any loss in the output voltage magnitude or increase in the total

harmonic distortion content. A further simplified technique is also presented in this study, which significantly

reduces the complexity and effort involved in the seven-level SVM. Simulation results for the seven-level

CHB inverter using the proposed techniques are presented. The results are compared with results using

sinusoidal pulse-width modulation (PWM) and third harmonic injection PWM to prove the validity of the

proposed techniques. The proposed technique is perfectly general and can be applied to all types of multilevel

inverters and extended to higher level inverters.

ETPL

PE - 019

Simplified space vector modulation technique for seven-level cascaded H-bridge

inverter

This paper presents a new pulse width modulation (PWM) strategy, called extended double carrier PWM, for a

two-level voltage source inverter aiming at reducing the RMS current flowing through dc link filtering

capacitors on embedded systems over a large modulation index range and for high-power factor loads (cos φ ≥

0.8). Instead of utilizing two adjacent active vectors at each switching period as in classic PWM strategies, this

new strategy utilizes two nonadjacent active vectors in the case of low-modulation index or three consecutive

active vectors in the case of high-modulation index. Analytical calculations show that this new strategy is

particularly effective in terms of reducing filtering capacitor rms current for high-power factor compared to

space vector PWM which is used as a reference strategy. The impact of this strategy on output current quality

is also investigated.

ETPL

PE - 018

Extended Double Carrier PWM Strategy Dedicated to RMS Current Reduction

in DC Link Capacitors of Three-Phase Inverters








This paper describes and evaluates an adaptive neuro-fuzzy inference system (ANFIS)-based energy

management system (EMS) of a grid-connected hybrid system. It presents a wind turbine (WT) and

photovoltaic (PV) solar panels as primary energy sources, and an energy storage system (ESS) based on

hydrogen (fuel cell -FC-, hydrogen tank and electrolyzer) and battery. All of the energy sources use dc/dc

power converters in order to connect them to a central DC bus. An ANFIS-based supervisory control system

determines the power that must be generated by/stored in the hydrogen and battery, taking into account the

power demanded by the grid, the available power, the hydrogen tank level and the state-of-charge (SOC) of

the battery. Furthermore, an ANFIS-based control is applied to the three-phase inverter, which connects the

hybrid system to grid. Otherwise, this new EMS is compared with a classical EMS composed of state-based

supervisory control system based on states and inverter control system based on PI controllers. Dynamic

simulations demonstrate the right performance of the ANFIS-based EMS for the hybrid system under study

and the better performance with respect to the classical EMS.

ETPL

PE - 020

ANFIS-Based Control of a Grid-Connected Hybrid System Integrating

Renewable Energies, Hydrogen and Batteries

This paper presents a family of exponential voltage step-down switched-capacitor (ESC) converters.

Considering the demand of large-voltage-gain step-down converters in the market, it is difficult to achieve the

step-down requirement with good efficiency for a single-stage buck converter. The two-stage converter has

been an effective solution for high-voltage-step-down applications. In this paper, making use of the large-

voltage-gain conversion property of the ESCconverter, a two-stage ESC-buck converter is proposed. A

mathematical tool for the accurate calculation of efficiency is developed. The efficiency characteristic of the

proposed ESCconverter is established. Experimental efficiency measurements are carried out using the

ESC converterproposed and two different types of commercially available buck converter ICs. The results

show that the efficiency of the ESC-buck converter is higher than that of a single buckconverter for large-

voltage-gain applications.

ETPL

PE - 021

A Family of Exponential Step-Down Switched-Capacitor Converters and Their

Applications in Two-Stage Converters








This paper presents a half-bridge LLC resonant converterhaving a boost pulse width modulation

(PWM) convertercharacteristic for hold-up state operation. The proposedconverter is based on a half-bridge

LLC resonant converterstructure and a single auxiliary switch is added at the primary side. The converter has

two different operational characteristics. It shows the same operational characteristic with the conventional

LLC resonant converters during nominal state, which is frequency modulation (FM) method. However, when

ac line lost and the converter enters into the hold-up time state, which requires wide voltage gain changes, the

control method of the proposed converter is changed to the PWM method using the auxiliary switch. Since the

proposed converter compensates wide voltage gain variation with PWM method of the auxiliary switch rather

than adopting the FM method of main switches, the frequency variation range for the LLC

resonant converter is highly reduced in the proposed converter. Therefore, the transformer in the

proposed converter can be designed at the optimal operating point and it results in decreased conduction loss

of the magnetizing inductor current. Furthermore, the maximum voltage gain of the proposedconverter is

easily increased by extending the duty ratio of the auxiliary switch. It helps to decrease the link capacitance.

To verify the effectiveness of the proposed circuit, operational principle will be explained and experimental

results will be presented with following specification. 100 kHz of switching frequency, 250-400 V of input

voltage range, 250 V of output voltage, and 75 W output power.

ETPL

PE - 022

A Half-Bridge LLC Resonant Converter Adopting Boost PWM Control Scheme

for Hold-Up State Operation








This paper presents a new extendable single-stage multi-input dc-dc/ac boost converter. The proposed

structure comprises of two bidirectional ports in the converter's central part to interface output load and battery

storage, and several unidirectional input ports to get powers from different input dc sources. In fact, the

proposed topology consists of two sets of parallel dc-dc boost converters, which are actively controlled to

produce two independent output voltage components. Choosing two pure dc or two dc-biased sinusoidal

values as the converter reference voltages, situations of the converter operating in two dc-dc and dc-ac modes

are provided, respectively. The proposed converterutilizes minimum number of power switches and is able to

step up the low-level input dc voltages into a high-level output dc or ac voltage without needing any output

filter. The converter control system includes several current regulator loops for input dc sources and two

voltage regulator loops for generating the desired output voltage components, resulting in autonomously

charging/discharging the battery to balance the power flow. Due to the converterinherent multi-input

multioutput control system, the small signal model of the converter is extracted and then the pole-placement

control strategy via integral state feedback is applied for achieving the converter control laws. The validity and

effectiveness of the proposed converter and its control performance are verified by simulation and

experimental results.

ETPL

PE - 023

New Extendable Single-Stage Multi-input DC–DC/AC Boost Converter

This paper presents a new three-level zero-voltage switching (ZVS) dc/dc converter for high input voltage

applications. There are two ZVS circuits in the proposedconverter to share load current. Thus, the size of the

output chokes is reduced. These two circuits use the same power switches. Thus, the proposed converter has

less switch counts compared with the conventional parallel three-level ZVS dc/dc converter. In the

proposed converter, each circuit combines one half-bridge converter and one three-levelconverter. The

transformer secondary windings of twoconverters are connected in series to reduce the size of output inductor.

The voltage stress of each power switch is limited at one-half of input voltage due to three-level circuit

topology. Based on the resonant behavior by the output capacitance of active switches and the leakage

inductance (or external inductance) at the transition interval, power switches are turned on at ZVS within the

desired load range. Experiments based on a 1.5 kW prototype are provided to demonstrate the performance of

the proposed converter.

ETPL

PE - 024

New Parallel ZVS Converter With Less Active Switches and Smaller Output

Inductance








A new LLC series resonant converter that has a narrow switching frequency variation and reduced conduction

losses is proposed in this paper. In the proposed converter, one leg of the full-bridge diode rectifier is replaced

with synchronous rectifier (SR) switches. In the nominal state, the proposed converter is controlled using

frequency modulation, and the SR switches are controlled using in-phase switching signals with primary side

switches in order that the proposed converter can obtain a reduced conduction loss in its secondary side

rectifiers. During the hold-up time which is the condition where the input voltage of the converter decreases,

the SR switches are controlled using phase-shifted switching signals in order that the proposed converter can

obtain a higher gain without decreasing the switching frequency. Because the proposedconverter operates with

a narrow switching frequency variation, a small transformer core can be selected, which results in a decreased

core size and loss. Furthermore, it is possible for the proposed converter to be designed optimally in the

nominal state and this results in the proposedconverter exhibiting a maximized efficiency over the entire load

condition. The feasibility of the proposed converter is verified with a 400-250 V input and 200 V/1.5 A output

prototype.

ETPL

PE - 025

A New LLC Series Resonant Converter with a Narrow Switching Frequency

Variation and Reduced Conduction Losses

The combination of minimum time control and multiphaseconverter is a favorable option for dc-

dc converters in applications where output voltage variation is required, such as RF amplifiers and dynamic

voltage scaling in microprocessors, due to their advantage of fast dynamic response. In this paper, an

improved minimum time control approach for multiphase buck converter that is based on charge balance

technique, aiming at fast output voltage transition is presented. Compared with the traditional method, the

proposed control takes into account the phase delay and current ripple in each phase. Therefore, by

investigating the behavior of multiphase converter during voltage transition, it resolves the problem of current

unbalance after the transient, which can lead to long settling time of the output voltage. The restriction of this

control is that the output voltage that the converter can provide is related to the number of the phases, because

only the duty cycles at which the multiphase converter has total ripple cancellation are used in this approach.

The model of the proposed control is introduced, and the design constraints of the buck converter's filter for

this control are discussed. In order to prove the concept, a four-phase buck converter is implemented and the

experimental results that validate the proposed control method are presented. The application of this control to

RF envelope tracking is also presented in this paper.

ETPL

PE - 026

Minimum Time Control for Multiphase BuckConverter: Analysis and

Application








Presently, there is an immense impetus in the automotive industry to develop plug-in electric vehicles (PIEVs)

to reverse the ever increasing green house gas emissions from fossil fuels and depleting fossil fuel resources.

High-frequency ac-dc converters with an isolated output are one of the essential building blocks for

transferring power from utility mains to the traction battery packs which store energy for propelling the EV.

Generally, the ac/dc converters used in EVs include a PFC stage at the input side and an isolated

dc/dc converter at the battery side. Due to the switching nature of the converter, electromagnetic compatibility

(EMC) of these converters is an essential requirement, to ensure not only its own operation but also the safe

and secure operation of surrounding electrical equipment. EVs possess a lot of sophisticated electronic circuits

in the vicinity of the battery charging power converters. Thus, strict EMC standards of the on-board

power converters must be met according to the CISPR 12 or SAEJ551/5 relevant EMC standards.

Conventional passive filters used for EMI mitigation in power converters, comes at the expense of cost, size

and weight, power losses, and printed circuit board real estate. In this paper, an electromagnetic interference

(EMI) filter embedded into the main high-frequency planar transformer used in the dc/dc converter is

proposed as a very cost-effective and efficient solution for EVs. The proposed structure is able to significantly

suppress the common-mode (CM) EMI noise generated in the dc/dcconverter. Experimental results have been

obtained from a 3-kW prototype in order to prove the feasibility and performance of the proposed EMI filter.

The results show that the proposed embedded EMI filter can effectively suppress the CM noise particularly for

high switching frequency power converters. The proposed structure can be a very simple and cost-effective

EMI filtering solution for future PIEVs.

ETPL

PE - 027

An Improved Layout Strategy for Common-Mode EMI Suppression Applicable to

High-Frequency Planar Transformers in High-Power DC/DC Converters Used for

Electric Vehicles








Almost all previously proposed single-stage, three-phase ac-dc converters are based on the boost converter,

and the strengths and weaknesses of boost-based single-stage converters are well known. This is not the case

for buck-based single-stage converters as little, if any, comparable research has been performed on

these converters. The authors have previously investigated a three-phase ac-dc, single-stage buck-

type converter that can simultaneously perform power factor correction and dc-dc conversion using the

standard phase-shift pulse-width modulation technique for dc-dc full-bridge converters. This paper is a

continuation of that work as its main focus is a comparison of the performance and characteristics of

this converter with those of a modified version of the same converter. In this paper, the fundamental principles

of both the converters are explained, the modes of operation of the modified converter are explained in detail

and a procedure for the design of this converter is demonstrated with an example. Experimental results

obtained from a prototype of the modified converter are presented and based on these results; the two

converters are compared in terms of parameters such as input power factor and efficiency.

ETPL

PE - 028

A Comparative Study of Two Buck-Type Three-Phase Single-Stage AC–DC

Full-Bridge Converters

This paper proposes a single-stage three-phase-to-single-phase current-fed high step-up ac–dc

matrix converter. The proposed converter inserts a boost-type matrix converter, which is formed by three

boost inductors and six bidirectional switches, between a three-phase ac source and a Cockcroft–Walton

voltage multiplier (CWVM). By using this topology associated with power factor correction technique, the

proposed converter not only achieves almost unity power factor and sinusoidal input currents with low

distortion but also obtains high voltage gain at the output end. Moreover, the matrix converter generates an

adjustable-frequency and adjustable-amplitude current, which injects into the CWVM to regulate the dc output

voltage and smooth its ripple. With this flexible injection current, the performance of the proposed converter is

superior to the conventional CWVM, which is usually energized by a single-phase ac source. The operation

principle, control strategy, and design considerations of the proposed converter are detailed in this paper.

Finally, simulation and experimental results demonstrate the claims and validity of the proposed converter.

ETPL

PE - 029

A Cockcroft–Walton Voltage Multiplier Fed by a Three-Phase-to-Single-Phase

Matrix Converter With PFC








In this paper, a novel modular cascaded multi-level converterwith multiwinding high-frequency (MWHF)

transformer is proposed for medium- or high-voltage applications. In the proposed converter, a cascaded H-

bridge rectifier (CHBR) is connected directly with the input ac source while the traditional step-down

transformer is no longer necessary. Then, an isolated dc-dc converter composed by a group of H-

bridge converters and a MWHF transformer with high power density is used to isolate the dc buses produced

by the CHBR. The equivalent circuit and mathematical model of the MWHF transformer and the high

frequency (HF) converterare obtained firstly in this paper. Then, the voltage stability under unbalanced loads

is analyzed and the naturally balance ability is verified. To accelerate the dc bus voltage balancing process, a

voltage balance control algorithm based on energy exchange between different transformer windings is

proposed that is realized by accomplishing the phase shift adjustment of the terminal voltages on different

windings. Simulations and experiments are implemented to verify the performance of the

proposed converter and voltage balance algorithm.

ETPL

PE - 030

Stability and Voltage Balance Control of a ModularConverter With

Multiwinding High-Frequency Transformer

In this paper, a novel three-port converter (TPC) with high-voltage gain for stand-alone renewable power

system applications is proposed. This converter uses only three switches to achieve the power flow control.

Two input sources share only one inductor. Thus, the volume can be reduced. Besides, the conversion ratio of

the converter is higher than other TPCs. Thus, the degree of freedom of duty cycle is large. The converter can

have a higher voltage gain for both low-voltage ports with a lower turns ratio and a reasonable duty ratio. The

voltage stress of switches is low; thus, conduction loss can be further improved by adopting low

Rds(on) switches. Therefore, the converter can achieve a high conversion ratio and high efficiency at the same

time. The operation principles, steady-state analysis, and control method of the converter are presented and

discussed. A prototype of the proposed converter with a low input voltage 24 V for photovoltaic source, a

battery port voltage 48 V, and an output voltage 400 V is implemented to verify the theoretical analysis. The

power flow control of theconverter is also built and tested with a digital signal.

ETPL

PE - 031

Novel Three-Port Converter With High-Voltage Gain








This paper presents the analysis of automatic generation control (AGC) of interconnected thermal-thermal

power system each containing two units in the conventional environment. The improvement of AGC with the

addition of a small capacity capacitive energy storage (CES) unit with different type of controllers in both the

areas is studied. Time domain simulations are used to study the performance of the power system and control

logic. Suitable method for controlling the thermal-thermal power system is described. Analysis reveals that

CES unit fitted in either of the areas is as effective as CES units fitted in both the areas and improves the

dynamic performances a considerable extent following a load disturbance in either of the areas. Simulation

studies carried out on a two-area interconnected power system each containing two units, with and without

considering CES units, shows that the proposed control schemes are very effective for the generators taking

part in load following.

ETPL

PE - 032

Effect of different controllers and capacitive energy storage on two area

interconnected power system model using Matlab Simulink

The analysis and control of Double-input integrated dc-dc converter is presented in this paper. The integrated

converter is essentially a combination of buck and buckboost converters. However, on account of integration

only one inductor is sufficient enough for performing the power conversion. In order to have simple control

strategy as well as simpler compensator design a single loop control scheme, voltage-mode and current-limit

control are proposed here for the power distribution. Closed-loop converter performance of this converter is

simulated and compared with the theoretical predictions. The prototype of this converter is presented and the

results are compared with simulinkmodel.

ETPL

PE - 033

Analysis and control of Double input Dc-Dc converter








This paper introduces a versatile unidirectional ac-dc converter with harmonic current and reactive power

compensation. Since numerous unidirectional ac-dc converters can be connected with ac power systems,

existing commercial converters possess the ability to improve substantially the stability of ac power systems

by compensating harmonic current and reactive power. In this paper, the feasibility and limitations of the

unidirectional ac-dc converter are explained when it is employed for harmonic current and reactive power

compensation, and a control strategy for such functionalities is proposed. A MATLAB /Simulink model and a

1 kW dual boost PFC prototype board controlled by a digital signal processor are implemented to demonstrate

the effectiveness of the proposed control method for improving power quality of the grid.

ETPL

PE - 034

Versatile unidirectional AC-DC converter with harmonic current and reactive

power compensation for smart grid applications

This paper discusses the droop control method for inverters participating in low voltage microgrids and its

application as a primary control layer which can be actuated from a secondary control layer to dispatch active

and reactive power. To that end, an independent and decoupled relationship between frequency and active

power; and voltage and reactive power is desirable. When the classic droop control method is applied to

inverters connected to the microgrid through RL type impedance, this decoupled actuation is lost. Different

variants of decoupled techniques are presented and analyzed from the point of view of static and dynamic

behavior. The analysis is supported on a linear dynamic phasor model of the droop controlled inverter, and

verified by simulations of behavior in an isolated microgrid and in grid tied mode using a

detailedSIMULINK/SimPowerSystems model of the inverter and its internal control. Among the diverse

techniques, the recently proposed droop control method with dynamic decoupling is signaled as advantageous,

not only in terms of decoupled actuation but also in flexibility in adjustment of static and dynamic response.

ETPL

PE - 035

Decoupled droop control techniques for inverters in low-voltage AC microgrids








This paper presents an AC-DC converter design for applications where mains frequency is widely varied and

low input current harmonics and output voltage regulation are required, for example, in aircraft power

systems. The proposed design employs a Single Ended Primary Inductance Converter (SEPIC) at the DC-end

of a single-phase bridge diode rectifier. In discontinuous conduction mode (DCM), the SEPIC converter is a

good alternative to the conventional buck or boost converter, where a low input current harmonic content is

achieved with proper inductor selection of the converter. Here, a 28V, 1kW converter design with variable

mains frequency (360 to 800Hz) is presented. The system performance was examined through a

Matlab/ Simulinkmodel during both transient and steady state conditions.

ETPL

PE - 036

SEPIC AC-DC converter for aircraft application

This exertion explains the built-in photovoltaic based dynamic voltage restorer (DVR) for alleviation of

voltage hang down and engorge mitigation. Photo Voltaic (PV)model, DVR model and local grid model are

implemented and the results of simulation are presented. In order to improve the efficiency of the PV system

Incremental Conductance (INC) algorithm based Maximum Power Point Tracker (MPPT) is connected. The

cascaded H-bridge multilevel inverter is used for exchange of real and reactive power to the sensitive load

from PV system. Modeling of the proposed system was developed by MATLAB Simulink. The objective of

the proposed system is to study the system behaviour, which allows the renewable energy sources for

mitigating voltage disturbances.

ETPL

PE - 037

Power quality enhancement using photovoltaic based dynamic voltage restorer








Solar energy is a renewable and a vast source of primary energy to electricity. PV module is increasingly

employed in utilizing the sun's energy for generating electrical energy. The photovoltaic pumping has become

one of the most promising fields in photovoltaic applications especially in remote locations. As the output

characteristic of a photovoltaic module is nonlinear and changes with solar irradiation and cell's temperature

so attention is paid to their design and their optimal use. Therefore a Maximum Power Point Tracking (MPPT)

technique is needed to maximize the produced energy. In this paper, the proposed work is to extract maximum

power from the PV array to powered water pumping system. Boost converter with Constant voltage MPPT

(CVMPPT) technique is employed to drive centrifugal pump through permanent magnet DC motor. The

1KWp solar PV array is designed and modeled in MATLAB Simulinkenvironment. CVMPPT is implemented

in Xilinx system generator which is interfaced with MATLAB Simulink to control the DC-DC boost

converter model in order to extract power to drive PMDC motor. The detailed study is carried out and the

results are presented.

ETPL

PE - 038

Performance and control system design for FPGA based CVMPPT boost

converter for remote SPV water pumping system applications

Flexible ac transmission systems, as a key building block of transmission-level smart girds, have shown

effective functionalities in promoting the system operation security and service reliability. Facing with series-

compensated lines, subsynchronous resonance (SSR) may strike the powersystem by jeopardizing

its stability and mechanical facilities. The operation of such transmission lines is broadening as a direct result

of emergent desire to exploit distant wind energy resources in large scales. This paper verifies the capability of

unified power flow controller (UPFC) in attenuating SSR in wind farm integrations. SSR is local in its nature;

hence, local measurements are merely employed here for controlling the series convertor while wide-area

signals could be as well utilized in parallel for other objectives such as inter-area oscillation damping. An

equivalent self-excited induction generator (SEIG) represents the wind farm and is connected to

the systemthrough a series-compensated line. The UPFC is located at the wind terminal of the linking line;

thus, the needed reactive power of SEIG is produced by the shunt branch of UPFC. Both SSR types, namely

generator effect and torsional interaction, are examined here. Simulations are carried out on the IEEE first SSR

benchmark model integrated with a SEIG wind turbine.

ETPL

PE - 039

Application of UPFC to Enhancing Oscillatory Response of Series-Compensated

Wind Farm Integrations








Voltage-sourced converter (VSC)-based static synchronous compensators (STATCOMs) are used for voltage

regulation in transmission and distribution systems. Unlike PWM-controlled STATCOMs, angle-controlled

STATCOMs are switched at line frequency to limit the system losses. In recent years, angle-controlled

STATCOMs have been deployed by utilities for the purpose of transmission system voltage regulation,

voltage stability improvement, and increasing operational functionality. Despite the superior feature on voltage

waveform quality and efficiency, the practical angle-controlled STATCOMs suffer from the over-current (and

trips) and possible saturation of the interfacing transformers caused by negative sequence current during

unbalanced conditions and faults in the utility. This paper specifically proposes a control structure to improve

the angle-controlled STATCOMs performance under unbalanced conditions and faults. The main

improvement is a substantial decrease in the negative sequence current and dc-link voltage oscillations under

power system faults by the proposed control. This eliminates the need to redesign the STACOM power

components to operate under fault current and dc-link voltage oscillations. The proposed control structure

is designed based on adding appropriate oscillations to the conventional angle-controller output that is the

control angle by which the VSC voltage vector leads/lags the line voltage vector. Since this control structure

uses two angles for controlling the VSC output voltage, it is called dual angle control (DAC).

PSCAD/EMTDC and experimental results verify the validity of the proposed control structure under

unbalanced system conditions and faults. The experiments were conducted on a transient network analyzer, a

unique hardware-based flexible ac transmission system simulator which was designed to study system faults

and transients for a 2 × 100 MVA STATCOMfield installation.

ETPL

PE - 040

Dual Angle Control for Line-Frequency-Switched Static Synchronous

Compensators Under System Faults








Electric Arc Furnaces (EAF) are high power industrial loads which cause power quality problems at all

voltage levels due to their unbalanced and nonlinear characteristics. The rapid, stochastic large swings in real

and reactive power required by the arc furnace causes voltage drops, rapid voltage variation and distortion

across the ac supply network. These voltage drops and fluctuations not only have negative impact on the

power system quality and other loads, but also have an effect on the arc furnace operation, power output and

efficiency. Hence, some sort of reactive compensation is required to limit the voltage disturbances injected by

arc furnace into the electric power system. In this paper, an accurate electric arc furnace model, whose

parameters have been set according to a 80 MVA actual arc furnace, is studied. A Static VAR Compensator

(SVC) is simulated in PSCad and Real Time Digital Simulation (RTDS)/RSCAD platform for the purpose of

comparison of voltage regulation at EAF bus. It is shown that the SVC mitigates the reactive power

fluctuations in addition to providing the fundamental reactive power, and regulates the Point of Common

Coupling (PCC) bus voltage precisely during the arc furnace operation. To verify the PSCad simulation results

and make a comparison, a real time simulation study based on Real Time Digital Simulation (RTDS)/RSCAD

platform has been performed in this case. On the other hand, a 80 MVA static synchronous compensator

(STATCOM) is simulated in PSCad. It is illustrated that the SVC is inherently limited in its ability to respond

rapidly to the fluctuating arc furnace load. It is found that the transient performance of the EAF voltage in case

which equipped with the STATCOM is better than the case equipped with SVC. It is also demonstrated that

although the voltage regulation by the SVC compensates a portion of the reactive power fluctuation, it is

completely unable to supply any portion of the fluctuating real power drawn by the arc- furnace, while the

STATCOM can supply those components of active and reactive power fluctuation. The STATCOM will not

normally have a source of real power connected to its DC terminals. It is therefore unable to supply sustained

real power or real power fluctuations. With suitable choice of DC capacitor, however, it is capable of

supplying in large part the fluctuating real power requirement of the furnace.

ETPL

PE - 041

SVC and STATCOM application in Electric Arc Furnace efficiency

improvement








This paper presents a single-ended traveling wave-basedfault location method for a hybrid transmission line:

an overhead line combined with an underground cable. Discrete wavelet transformation (DWT) is used to

extract transient information from the measured voltages. Support vector machine (SVM) classifiers are

utilized to identify the faulty-section and faulty-half. Bewley diagrams are observed for the traveling wave

patterns and the wavelet coefficients of the aerial mode voltage are used to locate the fault. The transient

simulation for different fault types and locations are obtained by ATP using frequency-dependent line and

cable models. MATLAB is used to process the simulated transients and apply the proposed method. The

performance of the method is tested for different fault inception angles (FIA), different fault resistances, non-

linear high impedancefaults (NLHIF), and non-ideal faults with satisfactory results. The impact of cable aging

on the proposed method accuracy is also investigated.

ETPL

PE - 042

A Machine Learning and Wavelet-Based FaultLocation Method for Hybrid

Transmission Lines

This paper proposes an adaptive low-dc-link-voltage-controlled LC coupling hybrid active power filter ( LC-

HAPF) with a neutral inductor, which can compensate both dynamic reactive power and current harmonics in

three-phase four-wire distribution power systems. Due to its adaptive low-dc-link-voltage characteristic, it can

obtain the least switching loss and switching noise and the best compensating performances, compared with

the conventional fixed and newly adaptive dc-voltage-controlled LC-HAPFs. The design procedures of the dc-

link voltage controller are discussed, so that the proportional and integral gains can be designed accordingly.

Moreover, the general design procedures for the adaptive dc-voltage-controlled LC-HAPF with a neutral

inductor are also given. The validity and effectiveness of the adaptive dc-link voltage-controlled LC -HAPF

with a neutral inductor are confirmed by experimental results obtained from a 220-V 10-kVA laboratory

prototype compared with the conventional fixed and adaptive dc-link voltage-controlled LC-HAPFs without a

neutral inductor.

ETPL

PE - 043

Design and Performance of an Adaptive Low-DC-Voltage-Controlled LC-Hybrid

Active Power Filter With a Neutral Inductor in Three-Phase Four-Wire Power Systems








The integration of high-voltage direct-current (dc) transmission lines in conventional alternating-current

(ac)systems would affect the indirect measurement of phasor measurement unit (PMU) devices since the

concept of phasors would not correspond to dc transmission circuits. The optimal PMU placement problem in

ac/dc systemssubjected to the system observability is presented in this paper by applying a mixed-integer

programming model. In practice, the cost of each PMU is variable as a function of PMU measurement

channels. This attribute is incorporated in the proposed model as well. In addition, the number of PMU

measurement channels is deemed to be technically limited; thus, the common assumption concerning

allocation of one PMU device to a single node is relaxed. The objective in the proposed optimization model is

to minimize the total installation cost of PMUs when considering the observability of ac/dc

transmission systems in the base case and contingency conditions. Numerical analyses are conducted for the

IEEE standard test systems and a large-scalesystem, and the results are discussed.

ETPL

PE - 044

Observability of Hybrid AC/DC Power Systems With Variable-Cost PMUs








In this paper, a new single-phase wind energy inverter (WEI) with flexible AC transmission system (FACTS)

capability is presented. The proposed inverter is placed between the wind turbine and the grid, same as a

regular WEI, and is able to regulate active and reactive power transferred to the grid. This inverter is equipped

with distribution static synchronous compensators option in order to control the power factor (PF) of the local

feeder lines. Using the proposed inverter for small-to-medium-size wind applications will eliminate the use of

capacitor banks as well as FACTS devices to control the PF of the distribution lines. The goal of this paper is

to introduce new ways to increase the penetration of renewable energy systems into the distribution systems.

This will encourage the utilities and customers to act not only as a consumer, but also as a supplier of energy.

Moreover, using the new types of converters with FACTS capabilities will significantly reduce the total cost

of the renewable energy application. In this paper, modular multilevel converter is used as the desired

topology to meet all the requirements of a single-phase system such as compatibility with IEEE standards,

total harmonic distortion (THD), efficiency, and total cost of the system. The proposed control strategy

regulates the active and reactive power using power angle and modulation index, respectively. The function of

the proposed inverter is to transfer active power to the grid as well as keeping the PF of the local power lines

constant at a target PF regardless of the incoming active power from the wind turbine. The simulations for an

11-level inverter have been done in MATLAB/Simulink. To validate the simulation results, a scaled prototype

model of the proposed inverter has been built and tested.

ETPL

PE - 045

Design and Implementation of an 11-Level Inverter With FACTS Capability for

Distributed Energy Systems








The usage of remote signals obtained from a wide-area measurement system (WAMS) introduces time delays

to a wide-area damping controller (WADC), which would degrade system damping and even cause system

instability. The time-delay margin is defined as the maximum time delay under which a closed-loop system

can remain stable. In this paper, the delay margin is introduced as an additional performance index for the

synthesis of classical WADCs for flexible ac transmission systems (FACTS) devices to damp inter-area

oscillations. The proposed approach includes three parts: a geometric measure approach for selecting feedback

remote signals, a residue method for designing phase-compensation parameters, and a Lyapunov stability

criterion and linear matrix inequalities (LMI) for calculating the delay margin and determining the gain of the

WADC based on a tradeoff between damping performance and delay margin. Three case studies are

undertaken based on a four-machine two-area power system for demonstrating the design principle of the

proposed approach, a New England ten-machine 39-bus power system and a 16-machine 68-bus power system

for verifying the feasibility on larger and more complex power systems. The simulation results verify the

effectiveness of the proposed approach on providing a balance between the delay margin and the damping

performance.

ETPL

PE - 046

Wide-Area Damping Controller of FACTS Devices for Inter-Area Oscillations

Considering Communication Time Delays

In this paper, static synchronous compensator (STATCOM)-based damping stabilizers are designed and

implemented to enhance the damping of the low frequency oscillations. The effectiveness of STATCOM gain

and phase modulation channels to improve the damping characteristics is investigated. The coordination

among the internal ac and dc voltage controllers and the proposed damping controllers on each channel is

designed. Differential evolution as an intelligent optimization technique is considered to design the

STATCOM supplementary damping controllers. The STATCOM-based stabilizer is implemented on a real-

time digital simulator (RTDS). The RTDS experimental setup of STATCOM with a power system is verified.

The nonlinear time domain simulation of the considered power system is presented to validate the proposed

damping stabilizers of low frequency oscillations. Comparisons with the reported results in the literature

demonstrate the effectiveness of the proposed stabilizer.

ETPL

PE - 047

RTDS Implementation of STATCOM-Based Power System Stabilizers








This paper presents an add-on self-tuning (ST) control scheme for a Unified Power Flow Controller (UPFC) to

assist its conventional PI control system in damping power oscillations. The ST control algorithm is based on a

Pole Shift (PS) technique that has previously been successfully applied in Adaptive Power System Stabilizers

(APSSs). For a wide range of operating conditions, the conventional PI-UPFC unless returned suffers from

insufficient/nonoptimal damping performance. To overcome this problem, the authors propose supplementing

the PI controllers with an ST feedback loop comprised of an identifier and a PS control algorithm. With a

CRLS identifier tracking the system conditions online, this scheme eliminates the need for PI parameter

retuning. Further, to correctly identify system parameters during large disturbances, a constrained recursive

least squares (CRLS) identification procedure is adopted here. An improved damping performance with the

proposed add-on scheme assisting the nonoptimal PI-UPFC is demonstrated for a two-area power system.

ETPL

PE - 048

An Add-On Self-Tuning Control System for a UPFC Application

Power electronic conversion units will serve as a key enabling technology for assisting in the continued

growth of grid-scale energy storage. This paper presents existing and future power electronic conversion

systems and components that aid the interconnection of grid-scale energy storage or utilize storage to

minimize grid disruption at all voltage classes including transmission, distribution, and future grid

architectures such as the microgrid. New R&D solutions to aid the interconnection process including efforts in

bidirectional charger design and potentially solid-state transformers (SSTs) are emphasized. The role of energy

storage to support micro grid research and growth, while highlighting power electronic behavior within this

environment, is considered. Last, an example that bridges the micro grid and energy storage theme is given

through the design and operation of a direct current (dc) electric vehicle (battery) charging station. When

appropriate, manufacturer solutions and success stories of utilizing latest battery technologies interfaced via

power electronic solutions at the utility scale are provided.

ETPL

PE - 049

Power Electronics for Grid-Scale Energy Storage








Increasing energy demand and growth of wind generation have significantly increased the stress on the electric

grid. The low investment in transmission infrastructure necessitates adoption of methods for efficient use of

existing resources. Power converter-based FACTS devices, capable of dynamic power-flow control, have been

the preferred solution to maximize utilization of existing infrastructure, but implementation of

traditional FACTS solutions at transmission level voltages is complex and cost prohibitive. This paper

proposes a power router (PR) for dynamic power-flow control in a meshed network. The proposed PR is

realized by augmenting a transformer with a fractionally rated back-to-back converter. The main advantages of

the proposed converter are the fractional converter rating and reduced low-frequency transformer requirement

compared to the traditional FACTS solutions. This paper outlines the proposed PR topology, control range,

controller design and demonstrates the functionality through simulation and experimental results.

ETPL

PE - 050

Power Router for Meshed Systems Based on a Fractionally Rated Back-to-Back

Converter

This letter presents a modulation technique for the modified coupled-inductor single-stage boost inverter (CL-

SSBI)-based grid-connected photovoltaic (PV) system. This technique can reduce the system leakage current

in a great deal and can meet the VDE0126-1-1 standard. To maintain the advantages of the impedance

network, only a diode is added in the front of the original topology, to block the leakage current loop during

the active vectors and open-zero vectors. On the other hand, the near-state pulse width modulation (NSPWM)

technique is applied with one-leg shoot-through zero vectors in order to reduce the leakage current through the

conduction path in the duration of changing from and to open-zero vectors. Simultaneously, the leakage

current caused by other transitions can also be reduced due to the fact that the magnitude of common-mode

voltages is reduced. Simulation results of the transformerless PV system are presented in two cases: modified

CL-SSBI modulated by maximum constant boost (MCB) control method and NSPWM. Experimental results

for both CL-SSBI topology modulated by the MCB control method and modified CL-SSBI topology

modulated by NSPWM are also obtained to verify the accurateness of theoretical and simulation models.

ETPL

PE - 051

A Transformer less Grid-Connected Photovoltaic System Based on the Coupled

Inductor Single-Stage Boost Three-Phase Inverter








Silicon Carbide (SiC) devices are becoming increasingly available in the market due to the mature stage of

development fact of their manufacturing process. Their numerous advantages compared to silicon (Si) devices,

such as, for example, higher blocking capability, lower conduction voltage drop, and faster transitions make

them more suitable for high-power and high-frequency converters. The aim of this paper is to study the

switching behavior of the two most-widely studied configurations of SiC devices in the literature: the

normally-on SiC JFET and the cascode using a normally-on SiC JFET and a low-voltage Si MOSFET. A

detailed comparison of the turn-on and turn-off losses of both configurations is provided and the results are

verified against the experimental efficiency results obtained in a boost converter operating in both continuous

conduction mode (CCM) and discontinuous conduction mode (DCM). Furthermore, special attention will be

paid to the switching behavior of the cascode configuration, analyzing the effect of its low-voltage Si

MOSFET and comparing different devices. The study carried out will confirm that the overall switching losses

of the JFET are lower, making it more suitable for operating in the CCM in terms of the overall converter

efficiency. However, the lower turn-off losses of the cascode show this device to be more suitable for the

DCM when ZVS is achieved at the turn-on of the main switch. Finally, all the theoretical results have been

verified in an experimental 600-W boost converter.

ETPL

PE - 052

Switching Performance Comparison of the SiC JFET and SiC JFET/Si

MOSFET Cascode Configuration

This paper unifies the underlying concepts of all basic single-switch, two-state, dc-to-dc voltage-

sourced converters, by duality, as generic related current and voltage-sourcedconverters. By using ac and dc

circuit theory, the three basicconverters can be transformed to yield all known transfer functions and realizes a

proliferation of 33 topologies, three being previously unidentified topologies with unique characteristics. The

circuit based systematic unifying approach offers new insight and an alternative interpretation to the origin of

the 33 topologies including the Zeta, Cuk, ±Luo, CSC, Landsman, and Sepic converters.Converter time-

domain simulations and corresponding practical results of the three new topologies extol and culminate the

concepts and analysis presented.

ETPL

PE - 053

Generation and Analysis of Canonical Switching Cell DC-to-DC Converters








In this letter, the properties of three-level dc/dc converters when used as switch-mode power supplies are

investigated to see how they compare to those of two-level converters and to see if they can be used to

improve light load efficiency. The letter compares the two converters and uses experimental results to make

conclusions about light load efficiency.

ETPL

PE - 054

An Investigation on the Novel Use of High-Power Three-Level Converter Topologies to

Improve Light-Load Efficiency in Low Power DC/DC Full-Bridge Converters

Interleaved dc-dc converters have been widely applied, because of their benefits related to efficiency, size,

thermal management, modularity, and output current ripple cancellation. These converters present an

enhanced fault tolerance capability, but an open-circuit fault can leads to ripple beyond load requirements.

This paper presents a fault-diagnostic method for interleaved dc-dc convertersusing only the dc-link current

derivative sign features. The dc-link current derivative is thoroughly studied for both healthy and faulty

modes. Its sign variation during different time intervals defined by the number of switches in conduction mode

contains important information for open-circuit fault detection. The presented method is robust to transients

and current imbalance between phases and no additional sensors are required. A photovoltaic system

application is presented to validate this method.

ETPL

PE - 055

Open-Circuit Fault Diagnosis in Interleaved DC–DCConverters

Fuel cells are a prime candidate for alternative power source of future on-board power distribution systems

such as those for the more-electric-aircraft and electric vehicles. These systems are comprised of a large

number of power converters, often provided by a variety of manufacturers. Modeling and simulation are

powerful tools to evaluate the system-level behavior but, due to confidentiality of manufacturers, black-box

behavioral models of the converters are required instead of the conventional ones. This paper proposes a

black-box modeling and identification method of dc-dc converters with input current control for fuel-cell

power conditioning. The model is simple, requires low computational cost for simulation, and the

identification procedure is based on simple experiments. Moreover, the model does not represent the internal

structure of the converter, so it can be provided by the manufacturer while protecting confidential data. The

method is illustrated in detail and validated by making use of a commercial dc-dc converter specifically

designed for fuel-cell power conditioning.

ETPL

PE - 056

Black-Box Behavioral Modeling and Identification of DC–DC Converters With

Input Current Control for Fuel Cell Power Conditioning








An architecture of multiple-integrated converter modules sharing an unfolding full-bridge inverter with a

pseudo dc link (MIPs) is proposed for grid-connected photovoltaic systems in this paper. The proposed

configuration can improve the power conversion, the control circuit complexity, and the cost competitiveness.

The proposed MIP is composed of distributed flyback dc-dc converters (DFCs) and an unfolding full-bridge

inverter with an ac filter. The DFCs can eliminate the shading effect by using the individual maximum power

point tracking. In conventional flyback-type single-phase utility-interactive inverters, discontinuous

conduction mode and boundary conduction mode are popular because of the inherent constant current-source

characteristics more desirable for grid connection and of the simple procedures for the controller design.

However, the operating mode suffers from a large current stress of the circuit components, which leads to the

low power efficiency. To avoid this, the DFCs operate under continuous conduction mode that allows reduced

current stresses and increased power efficiency, as well as low material cost. The current control loop of

the converters employs primary-side regulation contributing to improvement of dynamics as well as the cost

reduction significantly due to the elimination of the high-linearity photocoupler device. Development of a new

dc-current loop that maintains the level of dc-current injection into the grid within the levels stipulated by

IEEE 1547 will be dealt as well. The performance validation of the proposed design is confirmed by

experimental results of a 200-W hardware prototype.

ETPL

PE - 057

Analysis and Design of Grid-Connected Photovoltaic Systems With Multiple-

Integrated Converters and a Pseudo-DC-Link Inverter

Switched power converters are used to interface the dc output in modern distributed power generation systems,

which are usually aggregated to the main grid to yield the necessary power using interconnected modules.

Synthesis, modeling, and stability analysis of interconnected systems using cascaded converters working under

sliding-mode control are considered in this paper. A systematic procedure to synthesize cascaded connection

of dc-dc boost converters is introduced. The approach is based on making each module to behave as a suitable

canonical element for power processing. Three different elements are considered, which are the dc power

gyrator, the dc transformer, and the dc loss-free resistor. These canonical elements are designed by means of a

sliding-mode control theory and then their dynamic behavior is studied in detail. The sliding-mode conditions

for each case are derived in closed form to obtain design-oriented criteria for selecting the parameters of the

system. The aforementioned canonical elements are compared to select the most suitable one for a distributed

power system. Simulation results ensure the correctness of the proposed approach. Experimental

measurements corroborate the theoretical predictions and the numerical simulations.

ETPL

PE - 058

Synthesis of Canonical Elements for Power Processing in DC Distribution

Systems Using Cascaded Converters and Sliding-Mode Control








This paper presents small-signal impedance modeling of grid-connected three-phase converters for wind and

solar system stability analysis. In the proposed approach, a converter is modeled by positive-sequence and

negative-sequence impedance directly in the phase domain. It is further demonstrated that the two sequence

subsystems are decoupled under most conditions and can be studied independently from each other. The

proposed models are verified by experimental measurements and their applications are demonstrated in a

system test bed.

ETPL

PE - 059

Impedance Modeling and Analysis of Grid-Connected Voltage-Source

Converters

A perturb and observe algorithm based on both the power-current characteristic of a photovoltaic (PV) panel

and the sliding-mode control of the input inductor current of an associated converter is investigated in a static

application. A single ended primary inductance converter (SEPIC) converter charging a battery from a PV

generator illustrates the procedure whose effectiveness is proved with experimental results. The reported

technique is appropriate for distributed maximum power point tracking of PV systems with output series

connected DC-DC switching converters. In these systems, each converter is supplied by an independent PV

panel at the input port whereas its output port is connected in series with the output ports of the

other converters. The proposed converter interconnection is based on a transformer-less SEPIC because of the

capability of thisconverter to step-up or step-down the input voltage. The resulting system allows maximum

power extraction from each PV source even in cases of non-uniform irradiance.

ETPL

PE - 060

Maximum power point tracking based on sliding mode control for output-series

connected converters in photovoltaic systems








The modular multilevel converter is a promising topology for high-voltage and high-power applications. By

using sub modules equipped with dc-capacitors excellent output voltage waveforms can be obtained at low

switching frequencies. The rated energy storage of the sub module capacitors is a driving factor of the size,

cost, and weight of the sub modules. Although the modular multilevel converter has been thoroughly

investigated in the literature, a more detailed analysis of the energy-storage requirements will provide an

important contribution for dimensioning and analysis of modular multilevel converters. Such an analysis is

presented in this paper. The analysis relates the power transfer capability to the stored energy in

the converter and the findings are validated by both simulations and experimental results. The required size of

the sub module capacitors in a 4.5 MW grid-connected converter is first calculated and the calculated

operating range is then compared with simulation results. The experimental results show that if the average

capacitor voltage is allowed to increase 10% above the nominal value energy storage to power transfer ratio of

21 J/kW can be achieved. It is concluded that the presented theory can relate the power transfer capability to

the energy storage in the converter and is thus a valuable tool in the design and analysis of modular

multilevel converters.

ETPL

PE - 061

On Energy Storage Requirements in Modular Multilevel Converters

This paper introduces innovative nonisolated and isolated soft-switched dc-dc topologies with the step-

up/down ability. The nonisolated topology is constructed by adding a small ac capacitor in parallel with the

main inductor of the conventional buck-boost converter and replacing its semiconductor devices with the

reverse-blocking switches. By using a novel control scheme, true zero-voltage switching is realized at both

turn-on and turn-off of the power switches irrespective of the input voltage, output voltage, or load value. The

isolated form of the converter is created by substituting the main inductor with an air-gapped high-frequency

transformer, similar to the flyback converter. In this case, two smaller ac capacitors are placed on both sides of

the transformer to realize soft switching as well as passive clamping; no extra clamping circuit is required. The

basic operation of the proposed partial-resonant convertersincludes four modes and is described in detail. The

comprehensive analysis of the topologies is carried out as well. Various experimental results in different

operating conditions are provided to verify the performance of the proposed power converters.

ETPL

PE - 062

Partial-Resonant Buck–Boost and Flyback DC–DC Converters








This paper is focused on the improvement of the control range of matrix converters operating with nonunity

input power factor. The analysis leads to the determination in closed form of a modulation strategy that allows

increasing the maximum output voltage compared to the traditional strategies under the same operating

conditions. The improvement of the control range is made possible by the information provided by the

measurement of load currents, which is usually available in electric drives. The feasibility of the new strategy

is verified by computer simulations and experimental tests.

ETPL

PE - 063

Range of the Linear Modulation in Matrix Converters

Pulse-width-modulated (PWM) voltage-source converters(VSCs) are gaining widespread acceptance in

modern power systems. It has been shown recently that full-scale high-power PWM VSCs can induce negative

electrical damping at subsynchronous frequencies. However, active reshaping of the VSC incremental output

impedance to minimize the negative impacts of a VSC on subsynchronous damping is not reported. To fill out

this gap, this paper presents: 1) an extended analysis of the output impedance of a PWM-based two-level VSC;

and 2) more importantly, three simple and robust active reshaping techniques to maximize the positive

electrical damping in the sub synchronous frequencies without affecting the converter control performance.

The first reshaping technique uses the grid voltage and an active-damping controller to generate active

impedance that modifies the VSC impedance in the sub synchronous range. The second reshaping technique

uses an internal active damping controller to modify the dynamics of the phase-locked loop, which has

significant contribution to the negative impedance of the VSC. The third reshaping technique combines the

first and second techniques. The proposed active mitigation methods show excellent performance in reshaping

the VSC impedance and inducing positive electrical damping to mitigate possible sub synchronous

interactions between the VSC and the power network. Further, the proposed compensators show robust control

performance at different output power levels of the VSC without significant impact on the converter control

performance. A theoretical analysis and comparative time-domain simulation and experimental results are

presented to verify the validity and effectiveness of the proposed techniques.

ETPL

PE - 064

Active Mitigation of Sub synchronous Interactions Between PWM Voltage-

Source Converters and Power Networks








This paper proposes a systematic sizing methodology for switched-capacitor DC/DC converters aimed at

maximizing the converter efficiency under the die area constraint. To do so, we propose first an analytical

solution of the optimum switching frequency to maximize the converter efficiency. When the parasitic

capacitances are low, this solution leads to an identical contribution of the switches and transfer capacitors to

the converter output impedance. As the parasitic capacitances increase, the optimum switching frequency

decreases. Secondly, optimum capacitor and switch sizes for maximum efficiency are provided. We show that

the overdrive voltage strongly impacts the optimum switch width through the modification of their

conductance. To support the sizing methodology, a model of the efficiency of switched-capacitor

DC/DC converters is developed. It is validated against simulation and measurement results in 65 nm and 0.13

μm CMOS, respectively. The proposed sizing methodology shows how the converter efficiency can be traded-

off for die area reduction and what is the impact of parasitic capacitances on the converter sizing.

ETPL

PE - 065

A Sizing Methodology for On-Chip Switched-Capacitor DC/DC Converters

This letter defines selective harmonic elimination pulse width modulation (SHE-PWM) formulations for

single-phase, interleaved converters. Through precalculated solutions, interleaved converters work at the same

operating point while eliminating multiple low-order harmonics. It is shown that multiple continuous solutions

can be acquired for three-level interleaved waveforms. Extending the method to multiple levels further

complicates the problem and reduces both the number and continuity of the solutions. Searching for solutions

when the maximum possible number of harmonics, that can be minimized using this PWM method, is reduced

confirms that such compromise can provide additional solutions with a minimal effect on the waveform’s

harmonic distortion. The SHE-PWM considerations are verified with simulations and experimental results.

ETPL

PE - 066

Theoretical Considerations for Single-Phase Interleaved Converters Operated

With SHE-PWM








This paper discusses wide range soft switching solutions to a pulse width modulation (PWM) three-level (TL)

dc-dcconverter suitable for industrial applications, and proposes four kinds of new PWM TL dc-dc converters.

The presented topologies have the following desirable features: all switches in each circuit sustain only half of

the input voltage; off state voltage of the switches is directly clamped by the input capacitors and no added

primary clamping devices, such as clamping diodes, flying capacitors, are required; and phase shifted control

method can be used to achieve wide output range. The leading switches in the converters can only realize

zero-voltage switching (ZVS), while the lagging switches can obtain ZVS or zero-current switching in

different converters. Principle of operation and theoretical analysis are discussed. Experimental results are

included to verify the feasibility and advantages of the new topologies.

ETPL

PE - 067

Wide Range Soft Switching PWM Three-Level DC–DC Converters Suitable for

Industrial Applications

Fuel cell stacks and photovoltaic panels generate rather low dc voltages and these voltages need to be boosted

before converted to ac voltage. Therefore, high step-up ratio dc-dcconverters are preferred in renewable

energy systems. A new Z-source-based topology that can boost the input voltage to desired levels with low

duty ratios is proposed in this paper. The topology utilizes coupled inductor. The leakage inductance energy

can efficiently be discharged. Since the device stresses are low in this topology, low-voltage MOSFETs with

small RDS(on) values can be selected to reduce the conduction loss. These features improve

theconverter efficiency. Also, the converter has a galvanic isolation between source and load. The operating

principles and steady-state analysis of continuous and discontinuous conduction modes are discussed in detail.

Finally, experimental results are given for a prototype converter that converts 25 V dc to 400 V dc at various

power levels with over 90% efficiency to verify the effectiveness of the theoretical analysis.

ETPL

PE - 068

Isolated High Step-Up DC–DC Converter With Low Voltage Stress








A solid-state transformer (SST) is a high-frequency power electronic converter that is used as a distribution

power transformer. A common three-stage configuration of an SST consists of ac-dc rectifier, isolated dc-dc

dual-active-bridge (DAB) converter, and dc-ac inverter. This study addresses the controller design issue for a

dc-dc DAB converter when driving a regulated single-phase dc-ac inverter. Since the switching frequency of

the inverter stage is much higher than that of the DAB stage, the single-phase inverter is modeled as a double-

line-frequency (e.g., 120 Hz) current sink. The effect of 120-Hz current by the single-phase inverter is studied.

The limitation of a PI-controller, low gain at 120 Hz, is investigated. Two methods are proposed to improve

the regulation of the output voltage of DABconverters. The first one uses a bandstop filter and feedforward,

while the second method uses an additional proportional-resonant controller in the feedback loop. Theoretical

analysis, simulation, and experiment results are provided.

ETPL

PE - 069

Closed-Loop Control of DC–DC Dual-Active-BridgeConverters Driving Single-

Phase Inverters

A behavioral average-circuit model that analyzes hybridconverters that include a switched inductor and

switched capacitors is presented. The model can be used to calculate or to simulate the average static,

dynamic, and small-signal responses of hybrid converters. The model is valid for all operation modes of the

switched capacitor converters(SCCs) operating in the continuous and discontinuous conduction modes of the

switched inductor converter and is compatible with circuit simulators that include dependent sources. The

model was verified with simulations and experimentally. The experimental converter included a

boostconverter followed by a ×3 SCC. Good agreement was found between the behavior of the proposed

average model, full circuit simulations, and experimental results.

ETPL

PE - 070

Simulation of Hybrid Converters by Average Models








The basic equations of high-voltage direct currenttransmission lines' ion current field are consisted of electric

field Poisson equation, ion current density equation and the current continuity equation, hence, the key to

calculating total electric field is to solve the non-linear differential equations, but the calculation process is

very complicated. A simple algorithm is proposed to solve the problem in this study. First, the charge

simulation method, an accurate numerical method, is employed to calculate the distribution of the electrical

fields of a conductor. Then, the thought of emission charge is referred to calculate total electric field strength,

this method does not need to adopt Deutsch hypothesis, and it avoids solving complex differential equations;

hence, the calculation process can be greatly simplified. Finally, it is found that the calculated values agree

satisfactorily with data measured on laboratory models and full-scale test lines.

ETPL

PE - 071

Simple algorithm for calculating the total electric field of high-voltage direct

current transmission lines

In this study, an improved particle-swarm-optimization (IPSO) method with dynamically changing inertia

weight and acceleration coefficients is employed in determining the installed capacity selection of

a hybrid energy generation system (HEGS). The studied HEGS, which includes wind power, photovoltaic

(PV) and fuel cells, is used to suppress the penalty bill caused by exceeding the contract power capacity with

the power company and to supply the backup power when needed. The objective is to achieve the optimal

ratio of the installed capacity of the HEGS, so that each energy source can make the best contribution in

the system, satisfy the load demand at a minimal installation cost and shorten the payback period. To realize

this objective, the payback period is selected as the optimization objective function by considering the

installation cost and cost recovery. In the IPSO, the penalty technique is designed to solve

the optimization problem with equality and inequality constraints for updating the particle's position and its

global best position. The proposed IPSO algorithm has been examined, tested and compared with other

methods on the optimization problem and proven to be more efficient in searching the global solution through

numerical simulations of a real case.

ETPL

PE - 072

Installed capacity selection of hybrid energy generation system via improved

particle-swarm-optimization








Accurate and reliable wind power forecasting is essential to power system operation. Given significant

uncertainties involved in wind generation, probabilistic interval forecasting provides a unique solution to

estimate and quantify the potential impacts and risks facing system operation with wind penetration

beforehand. This paper proposes a novel hybrid intelligent algorithm approach to directly formulate optimal

prediction intervals of wind power generation based on extreme learning machine and particle swarm

optimization. Prediction intervals with associated confidence levels are generated through

direct optimization of both the coverage probability and sharpness to ensure the quality. The proposed method

does not involve the statistical inference or distribution assumption of forecasting errors needed in most

existing methods. Case studies using real wind farm data from Australia have been conducted. Comparing

with benchmarks applied, experimental results demonstrate the high efficiency and reliability of the developed

approach. It is therefore convinced that the proposed method provides a new generalized framework for

probabilistic wind power forecasting with high reliability and flexibility and has a high potential of practical

applications in power systems.

ETPL

PE - 073

Optimal Prediction Intervals of Wind Power Generation

This paper presents a high efficiency, continuous conduction mode (CCM), zero voltage switching (ZVS)

bridgeless AC-DC power-factor-correction (PFC) converter for neighborhood electric vehicle (NEV) battery

charging. The converter operates in both pulse-width-modulation (PWM) mode and resonant mode each

switching cycle and utilizes standard average-current-mode control. This new modulation technique is

hereafter referred to as hybrid-resonant PWM (HRPWM). All the semiconductor devices of the proposed

converter realize soft-switching, nearly eliminating all switching losses and reducing electromagnetic

interference (EMI). Moreover, all the semiconductor devices can operate without voltage overstress for a wide

universal AC input voltage range. The converter architecture exhibit low in-rush current and implementation

of lightning and surge protection system is easy. The detailed operation of the proposed converter, along with

the stress analysis of the circuit components, and detailed loss analysis are provided. The feasibility of the

converter is confirmed by comparing an experimental prototype of the benchmark hard switched AC-DC boost

converter. Through experimentation and analysis, the proposed converter can achieve a total loss reduction of

15 %, at 70 kHz switching frequency, 120 V input, and 400 V/650 W output in comparison to the

benchmark AC-DC boost converter.

ETPL

PE - 074

A soft-switching bridgeless AC-DC power factor correction converter for off-

road and neighborhood electric vehicle battery charging








This paper introduces a novel isolated hybrid resonant converter with smooth transition between multiple

operating modes. With the simple addition of a bidirectional ac switch, the highly-efficient series resonant

converter operating in the discontinuous conduction mode (DCM) is combined with a phase-shifted full-bridge

buck converter and a pulse width modulated (PWM) boost converter in order to provide high power

conversion efficiency over a wide input-voltage operating range utilizing a simple topology and simple control

techniques. First, the topology is introduced and the converter's operating modes are discussed. Next, closed-

loop input-voltage controllers are designed for the different operating modes and a smooth transition technique

is introduced using a two-carrier modulation scheme. Experimental results are provided to verify the proposed

system using a 300-W prototype that achieved a 97.5% California Energy Commission (CEC) weighted

efficiency with a 30-V input including all auxiliary and control losses.

ETPL

PE - 075

A hybrid resonant converter utilizing a bidirectional GaN AC switch for high-

efficiency PV applications

A new interleaved three-phase PFC AC-DC singlestage multilevel is proposed in this paper. The proposed

converter uses a flying capacitor structure with standard phase-shift PWM to improve efficiency, particularly

at light load conditions. In the paper, the operation and its steady-state characteristics are explained and its

design is discussed. The feasibility of the new converter is confirmed with experimental results obtained from

a prototype converter.

ETPL

PE - 076

A new interleaved three-phase single-stage PFC AC-DC converter with flying

capacitor








Offshore wind energy is now seen as a key contributor for the future renewable energy mix. HVDC

technology is among the chief technologies enabling widespread use of offshore wind. Thanks to their

numerous advantages, voltage-source converter-based-HVDC (VSC-HVDC) systems are expected to be the

technology of choice. Unfortunately, most of VSCs are defenseless against dc-side faults, such as two-level

VSCs, and half-bridge modular multilevel converters. This paper proposes the buck-boost inverter-based-

HVDC system (BBI-HVDC) as a means to overcome the limitations of the classical VSC-HVDC systems. The

proposed configuration does not only provide sinusoidal three-phase voltage, but also provides complete

blocking capability of ac-side contributions during a dc-side fault. The latter is achieved by simply disabling

the gating signals to the switches upon fault detection. The performance of the proposed system is illustrated

during normal conditions, ac-side faults, and dc-side faults. A simulation case study comparing the

performance of the conventional HVDC converters with the proposed system during dc-side faults is

conducted. The simulation results reveal the promising performance under normal operation as well as a

significant decrease in the dcfault current due to the ac-side contribution blocking capability of the BBI-

HVDC system during dc-side faults.

ETPL

PE - 077

Bidirectional Buck-Boost Inverter-Based HVDCTransmission System With AC-

Side Contribution Blocking Capability During DC-Side Faults

The integration of high-voltage direct-current (dc) transmission lines in conventional alternating-current (ac)

systems would affect the indirect measurement of phasor measurement unit (PMU) devices since the concept

of phasors would not correspond to dc transmission circuits. The optimal PMU placement problem in ac/dc

systems subjected to the system observ ability is presented in this paper by applying a mixed-integer

programming model. In practice, the cost of each PMU is variable as a function of PMU measurement

channels. This attribute is incorporated in the proposed model as well. In addition, the number of PMU

measurement channels is deemed to be technically limited; thus, the common assumption concerning

allocation of one PMU device to a single node is relaxed. The objective in the proposed optimization model is

to minimize the total installation cost of PMUs when considering the observ ability

of ac/dc transmission systems in the base case and contingency conditions. Numerical analyses are conducted

for the IEEE standard test systems and a large-scale system, and the results are discussed.

ETPL

PE - 078

Observability of Hybrid AC/DC Power Systems With Variable-Cost PMUs








In this paper, a new single-phase wind energy inverter (WEI) with flexible AC transmission system (FACTS)

capability is presented. The proposed inverter is placed between the wind turbine and the grid, same as a

regular WEI, and is able to regulate active and reactive power transferred to the grid. This inverter is equipped

with distribution static synchronous compensators option in order to control the power factor (PF) of the local

feeder lines. Using the proposed inverter for small-to-medium-size wind applications will eliminate the use of

capacitor banks as well as FACTS devices to control the PF of the distribution lines. The goal of this paper is

to introduce new ways to increase the penetration of renewable energy systems into the distribution systems.

This will encourage the utilities and customers to act not only as a consumer, but also as a supplier of energy.

Moreover, using the new types of converters with FACTS capabilities will significantly reduce the total cost

of the renewable energy application. In this paper, modular multilevel converter is used as the desired

topology to meet all the requirements of a single-phase system such as compatibility with IEEE standards,

total harmonic distortion (THD), efficiency, and total cost of the system. The proposed control strategy

regulates the active and reactive power using power angle and modulation index, respectively. The function of

the proposed inverter is to transfer active power to the grid as well as keeping the PF of the local

power lines constant at a target PF regardless of the incoming active power from the wind turbine. The

simulations for an 11-level inverter have been done in MATLAB/Simulink. To validate the simulation results,

a scaled prototype model of the proposed inverter has been built and tested.

ETPL

PE - 079

Design and Implementation of an 11-Level Inverter With FACTS Capability for

Distributed Energy Systems








Voltage-sourced converter (VSC)-based static synchronous compensators (STATCOMs) are used for voltage

regulation intransmission and distribution systems. Unlike PWM-controlled STATCOMs, angle-controlled

STATCOMs are switched at line frequency to limit the system losses. In recent years, angle-controlled

STATCOMs have been deployed by utilities for the purpose of transmission system voltage regulation,

voltage stability improvement, and increasing operational functionality. Despite the superior feature on voltage

waveform quality and efficiency, the practical angle-controlled STATCOMs suffer from the over-current (and

trips) and possible saturation of the interfacing transformers caused by negative sequence current during

unbalanced conditions and faults in the utility. This paper specifically proposes a control structure to improve

the angle-controlled STATCOMs performance under unbalanced conditions and faults. The main

improvement is a substantial decrease in the negative sequence current and dc-link voltage oscillations under

power system faults by the proposed control. This eliminates the need to redesign the STACOM power

components to operate under fault current and dc-link voltage oscillations. The proposed control structure is

designed based on adding appropriate oscillations to the conventional angle-controller output that is the

control angle by which the VSC voltage vector leads/lags the line voltage vector. Since this control structure

uses two angles for controlling the VSC output voltage, it is called dual angle control (DAC).

PSCAD/EMTDC and experimental results verify the validity of the proposed control structure under

unbalanced system conditions and faults. The experiments were conducted on a transient network analyzer, a

unique hardware-based flexible actransmission system simulator which was designed to study system faults

and transients for a 2 × 100 MVA STATCOM field installation.

ETPL

PE - 080

Dual Angle Control for Line-Frequency-Switched Static Synchronous

Compensators Under System Faults

It is widely recognised that large amounts of limited controlled renewable generation in smart grids bring

major challenges. The increasing complexity to solve thetransmission expansion planning (TEP) problem

emphasises the need to face it with new models and more efficient optimisation techniques. In this research

work, a load shedding formulation is proposed, extended for the ACmodel that takes into account shunt

compensation additions to solve the TEP problem. This allows an integratedtransmission line and shunt

compensation planning that can be solved more efficiently. To solve the TEP problem, an improved version of

local particle swarm optimisation is used. Solutions obtained in very well-known test and realistic networks

demonstrate that this implementation can be very interesting for practical use.

ETPL

PE - 081

Expansion planning for smart transmission grids using AC model and shunt

compensation








When a high voltage direct current (HVDC) link connects two distinct power systems, the latter are usually

modelled by two infinite buses. However, in some context of use, the HVDC links are no longer separating

two systems but they are embedded into meshed AC systems in parallel with otherAC lines and interact with

other elements of the power system. This led us to enhance the control objectives by considering stability

requirements. In this context, the previous modeling assumption presents serious limitations. Instead, a more

efficient control model is used. It is developed such that the concerned dynamics of the system are taken into

account during the synthesis. It is shown how the controllers of the HVDC converters can be synthesised using

the control model mentioned above such that global grid performances are ensured, in addition to the local

objectives like power and DC voltage control. In order to avoid remote measures, an output feedback control

which uses only local measures is developed. The new controller is tested in comparison with the standard

vector control and a non-linear feedback linearisation control via simulation tests. The tests showed that the

controller synthesised using the new control model contributes to a better coordination of the control actions

and thus improve grid performances. In particular, the transient stability of the neighbour zone is a priori taken

into account at the synthesis level.

ETPL

PE - 082

Control of high voltage direct current links with overall large-scale grid

objectives

This paper considers optimal transmission switching (OTS) to reduce generation cost by removing lines from

service. A mixed integer program (MIP) has been proposed to solve the OTS problem, based on the linear

direct current optimal power flow (DCOPF) model. Because of excessive computation times for large, real

systems, the MIP model has been followed by some heuristics, also based on the DCOPF, to obtain near-

optimal solutions quickly. However, the approximations in the DCOPF model may lead to poor choices

of lines to remove from service. We assess the quality of line removal recommendations that rely on a

previously published, DCOPF-based heuristic, by estimating actual cost reduction with the exact ACOPF

model, using the IEEE 118-bus and 300-bus test systems with several demand levels. We also extend this

heuristic to be based on the ACOPF and compare the quality of its recommendations to those of the DCOPF-

based heuristic. The DCOPF-based heuristic performs very poorly in several cases, even leading to cost

increases sometimes. There is a need for approximations to the ACOPF which are accurate enough to produce

reliably good results for OTS heuristics, but fast enough for practical use.

ETPL

PE - 083

Accuracies of Optimal Transmission Switching Heuristics Based on DCOPF

and ACOPF








A modular and scalable series compensation technique for enhancing controllability and flexibility in

power transmissionin distributed power systems is proposed. The concept is based on paralleling multiple

static synchronous series compensators (SSSC) through daisy-chained transformers to perform reactive power

compensation, and thus control the amount and direction of the power flow over thetransmission link. Each

compensator unit is under an autonomous control for regulating its output voltage. Its output current is coupled

to another compensator unit through one of the daisy-chained transformers, so that thetransmission current is

shared among the parallel-connected compensators. Modeling, design, and analysis of a compensator unit and

the proposed multiparallel-connected SSSC (MSSSC) architecture in an elementary two-machine system will

be presented. A 3-kVA MSSSC test bed with three-parallel-connected compensator units for a single-phase

system has been built and evaluated. The steady-state and transient current-sharing characteristics in forward

and reverse power transmission over the transmission link will be studied. The response of the MSSSC system

with each compensator unit engaged sequentially will also be investigated.

ETPL

PE - 084

Paralleling Multiple Static Synchronous Series Compensators Using Daisy-

Chained Transformers

In this paper, a high-efficiency high power density LLC resonant converter with a matrix transformer is

proposed. A matrix transformer can help reduce leakage inductance and the ac resistance of windings so that

the flux cancellation method can then be utilized to reduce core size and loss. Synchronous rectifier (SR)

devices and output capacitors are integrated into the secondary windings to eliminate termination-related

winding losses, via loss and reduce leakage inductance. A 1 MHz 390 V/12 V 1 kW LLC resonant converter

prototype is built to verify the proposed structure. The efficiency can reach as high as 95.4%, and the power

density of the power stage is around 830 W/in3.

ETPL

PE - 085

LLC Resonant Converter With Matrix Transformer








A component level dc transformer is described in which no alternating currents or voltages are present. It

operates by combining features of a homopolar motor and a homopolar generator, both dc devices, such that

the output voltage of a dc power supply can be stepped up (or down) with a corresponding step down (or up)

in the current. The basic theory for this device is developed, performance predictions are made, and the results

from a small prototype are presented. Based on demonstrated technology in the literature, this dc transformer

should be scalable to low megawatt levels, but it is more suited to high current than high voltage applications.

Significant development would be required before it could achieve the kilovolt levels needed

fordc power transmission.

ETPL

PE - 086

A DC Transformer

Droop control is the basic control method for load current sharing in dc microgrid applications. The

conventional dcdroop control method is realized by linearly reducing the dcoutput voltage as the output

current increases. This method has two limitations. First, with the consideration of line resistance in a droop-

controlled dc microgrid, since the output voltage of each converter cannot be exactly the same, the output

current sharing accuracy is degraded. Second, the dc-bus voltage deviation increases with the load due to the

droop action. In this paper, in order to improve the performance of the dc microgrid operation, a low-

bandwidth communication (LBC)-based improved droop control method is proposed. In contrast with the

conventional approach, the control system does not require a centralized secondary controller. Instead, it uses

local controllers and the LBC network to exchange information between converter units. The droop controller

is employed to achieve independent operation, and the average voltage and current controllers are used in each

converter to simultaneously enhance the current sharing accuracy and restore the dc bus voltage. All of the

controllers are realized locally, and the LBC system is only used for changing the values of the dc voltage and

current. Hence, a decentralized control scheme is accomplished. The simulation test based on

MATLAB/Simulink and the experimental validation based on a 2 × 2.2 kW prototype were implemented to

demonstrate the proposed approach.

ETPL

PE - 087

An Improved Droop Control Method for DC Microgrids Based on Low Bandwidth

Communication With DCBus Voltage Restoration and Enhanced Current Sharing

Accuracy








DC arc fault introduces major safety concerns in a wide variety of components in dc networks. However, the

randomness and instability of dc arc makes it difficult to be detected. In this paper, an experimental system

was designed and tested at different load current, dc source voltage, and gap length to evaluate the impact of

each parameter to the dc arc. Based on the experimental results, characteristics in the electrical behavior were

studied and fault detection oriented analysis was conducted. A detection algorithm utilizing both time and

time-frequency domain characteristics was proposed to differentiate between dc arc fault and normal

condition. The detection algorithm was then realized on a digital signal processing board and tested to verify

the effectiveness. Experimental results show that the proposed algorithm can detect arc fault in a timely

manner and is free of nuisance trip from normal circuit operations such as load change condition.

ETPL

PE - 088

Characteristic Study and Time-Domain Discrete- Wavelet-Transform Based

Hybrid Detection of Series DC Arc Faults

This study investigates the design of a high-efficiency bidirectional single-input multiple-output (BSIMO)

power converter. According to the power management, the proposed BSIMO converter can operate at a step-

up state (energy release) and a step-down state (energy storage). At the step-up state, it can boost the voltage

of a low-voltage input power source to a controllable high-voltage dcbus and middle-voltage output terminals.

If there is redundant energy in the high-voltage dc bus, one can reversely transmit the energy. The high-

voltage dc bus can take as the main power, and middle-voltage output terminals can supply powers for

individual middle-voltage dcloads or to charge auxiliary power sources (e.g. battery modules). In this study, a

coupled-inductor-based BSIMO converter utilises only three power switches to accomplish the bidirectional

power control with the properties of voltage clamping and soft switching, and the corresponding device

specifications are adequately designed. As a result, the objectives of high-efficiency power conversion,

bidirectional energy transmission, high step-up/step-down ratios and various output voltages with different

levels can be obtained. The effectiveness of the proposed BSIMO power converter is verified by experimental

results of a kW-level prototype in practical applications.

ETPL

PE - 089

High-efficiency bidirectional single-input multiple-output power converter








High voltage direct current (HVDC) transmission systems are becoming increasingly popular when compared

to conventional AC transmission methods. HVDC voltage source converters (VSC) can offer advantages over

traditional HVDC current source converter topologies; as such, it is expected that HVDC-VSCs will be further

exploited with the growth of HVDC transmission. This study presents the DC fault ride through capability and

new static synchronous compensator (STATCOM) modes of operation for the recently published alternate arm

converter, intended for the HVDC market. Operation and fault ride through of the converter during a local

terminal to terminal short circuit of the DC-link is demonstrated; during the fault STATCOM operation is also

demonstrated.

ETPL

PE - 090

DC fault ride-through capability and STATCOM operation of a HVDC hybrid

voltage source converter








Most mature converters topologies for ac power conversion are inverter types, which require relatively short

lifetime electrolytic capacitors. The cost, size, and weight of the converter are thus limited. While alternative

solutions based on the single-phase direct ac-ac topologies are subject to zero crossing constraints, which

prevent them from replacing the inverter with low reliability. In this paper, a novel virtual quadrature source-

based sinusoidal modulation approach is proposed. Also, improved single-phase-based direct ac-actopologies

are derived based on the high-frequency link concept. As a result, ac voltage output with arbitrary amplitude,

phase, and frequency can be synthesized only using the single-phase-based topologies. This feature eventually

enables the converters to perform functions such as power line conditioning and electrical ac motor drives.

Since no large dc link electrolytic capacitor is required, system reliability can be enhanced. Furthermore, the

cost and the size are reduced. The proposed approach and the circuits are presented and analyzed in detail.

Both simulation and experimental results show the effectiveness of the proposed concept and the converters

when applying to power line conditioning and electrical ac motor drive applications.

ETPL

PE - 091

Virtual Quadrature Source-Based Sinusoidal Modulation Applied to High-Frequency

Link Converter Enabling Arbitrary Direct AC-AC Power Conversion

As inverter-fed motor drives generate fast-switching voltage pulses, the transmission-line effects on long

motor cable and motor stator windings lead to overvoltage on the cable and motor terminals, as well as inside

motor stator windings, and also an increase in the common-mode current. Such phenomenon would cause

premature failure of motor and cable insulation. A general protective measure is the use of a passive filter,

such as RC and RLC filter, to reduce the voltage surges by matching the cable impedance and/or altering the

rise time of the voltage pulses. However, passive filters are bulky and lossy. This paper presents an active

motor terminal filter with energy recovery function that can achieve the same functions as the passive filters,

but consumes much less power. The proposed filter recovers energy gained from suppressing motor terminal

voltage surges and regenerating the recovered energy back to the whole system. An experimental filter has

been built and evaluated on a 1-hp three-phase motor drive system. A comparative study into the performance

among commonly used RC filter and RLC filter and the proposed filter will be given.

ETPL

PE - 92

Use of Synchronous Modulation to Recover Energy Gained From Matching

Long Cable in Inverter-Fed Motor Drives








As the development of isolated bidirectional full-bridge dc-dcconverter (IBDC), the dead-time effect has

become an apparent issue. This paper presents a comprehensive theoretical analysis and experimental

verification of dead-time effect in the IBDC. Besides the internal power transfer and phase drift phenomena

mentioned in previous works, there are also many other novel phenomena caused by the dead time, such as

voltage polarity reversal and voltage sag phenomena, etc. The paper gives a detailed switching

characterization of the IBDC with dead-time effect in all operation states. On this basis,

the transmission power characterization is analyzed comprehensively. Compared to the traditional theoretical

model, the transmission power model with dead-time effect is not a strictly monotone increasing function, the

relation curve is not symmetric around the median axis, and the zero point is not achieved at zero phase-shift

ratio. In addition, in different operation states, the characterization is also different. Finally, experimental

results verify the theoretical analysis.

ETPL

PE - 93

Dead-Time Effect of the High-Frequency Isolated Bidirectional Full-Bridge

DC–DC Converter: Comprehensive Theoretical Analysis and Experimental

Verification

This paper reviews recent advances of key components in isolated bidirectional dc-dc converter (IBDC) and

discusses potential of IBDC based on advanced components. The concept of safe operation area of IBDC is

proposed and clearly defined, which is determined by the intersection of the effective operation areas

of transmission power, current stress, and current root mean square. By analyzing efficiency and power

density characteristic, this paper points out that the efficiency optimization of IBDC needs to give way to the

power density optimization. On this basis, a novel synthetic discrete optimization design methodology of

IBDC based on advanced components for battery energy storage system (BESS) is proposed. Finally, an

experimental prototype is implemented, and some design suggestions for hardware optimization are provided.

The experimental results verify the effectiveness of the designed BESS and show that the practical

applications of next-generation high-frequency conversion system are expected with the appearance and

application of advanced components.

ETPL

PE - 94

A Synthetic Discrete Design Methodology of High-Frequency Isolated

Bidirectional DC/DC Converter for Grid-Connected Battery Energy Storage

System Using Advanced Components








The configuration of parallel inverter system (PIS) with common dc link and no isolation measure is proposed.

The gate control signals for switches in parallel inverters are synchronised to achieve ideal parallel operation

status. Adopting the double loop control method which is composed of an outer voltage loop and an inner

current loop, PIS has good dynamic response and robustness. In addition, the circulating current caused by the

delay time of control signal transmission is studied in detail. The proposed operation method is easy to be

implemented on the digital control board using digital signal processing and field programmable gate array.

The simulation and experimental results are presented to demonstrate the validity and features of the proposed

operation method.

ETPL

PE - 95

Operation method for parallel inverter system with common dc link

A new integrated circuit for motor drives with dual-mode control for EV/HEV applications is proposed. The

proposed integrated circuit allows the permanent magnet synchronous motor to operate in motor mode or acts

as boost inductors of the boost converter, and thereby boosting the output torque coupled to the

same transmission system or dc-link voltage of the inverter connected to the output of the integrated circuit. In

motor mode, the proposed integrated circuit acts as an inverter and it becomes a boost-type boost converter,

while using the motor windings as the boost inductors to boost the converter output voltage. Moreover, a new

control technique for the proposed integrated circuit under boost converter mode is proposed to increase the

efficiency. The proposed control technique is to use interleaved control to significantly reduce the current

ripple and thereby reducing the losses and thermal stress under heavy-load condition. In contrast, single-phase

control is used for not invoking additional switching and conduction losses under light-load condition.

Experimental results derived from digital-controlled 3-kW inverter/converter using digital signal processing

show the voltage boost ratio can go up to 600 W to 3 kW. And the efficiency is 93.83% under full-load

condition while keeping the motor temperature at the atmosphere level. These results fully confirm the

claimed merits for the proposed integrated circuit.

ETPL

PE - 96

Integrated Inverter/Converter Circuit and Control Technique of Motor Drives

With Dual-Mode Control for EV/HEV Applications








This study presents voltage magnitude and frequency control of a three-phase voltage source inverter for

distributed generations to achieve a seamless transfer between grid-tied mode and intentional islanding mode.

When the grid is normal, the inverter works in grid-tied mode. On the contrary, when the grid fault occurs, the

breaker connecting the inverter to the grid must be turned off and the inverter just supplies the power for local

loads. By varying the frequency and the magnitude of the inverter output voltage, an output power control,

with which the output active and reactive power can be precisely controlled, is presented. To improve the

transient response, a virtual inductor with high-pass filter in synchronous d-q frame is proposed. The

effectiveness of the virtual inductor is explained by the frequency response of the inverter. Finally,

experimental results are given to verify the effectiveness of the scheme.

ETPL

PE - 97

Voltage magnitude and frequency control of three-phase voltage source inverter

for seamless transfer

A high-frequency (HF) isolated dc/ac converter including an unfolding line connected inverter can be used as

the interface between a small-scale alternative energy generation system and the utility line. This paper

presents the review of operation of several different topologies of HF isolated dc/ac converters. They are

designed for illustration purpose and compared for their performance. It is found that the dual-LCL series

resonant dc/ac converter can maintain zero-voltage switching (ZVS) operation for all switches with low line-

current total harmonics distortion (THD) and high efficiency. Experimental results on a 500-W prototype

converter are included for validation purpose.

ETPL

PE - 98

A Comparison Study of High-Frequency Isolated DC/AC Converter Employing

an Unfolding LCI for Grid-Connected Alternative Energy Applications








Three-phase current reconstruction technique using dc current information in conventional two-level inverters

can be used for the purpose of cost reduction and sensor fault tolerance. A novel phase current reconstruction

scheme, with reduced immeasurable area and common mode voltage, is proposed in this paper. A tristate

pulse-width modulation technique has been employed, in which three adjacent switching states are used to

construct the reference voltage. The active switching states are arranged at the edge and the center of a PWM

cycle. Fixed sampling and simultaneous three-phase currents can be easily achieved with very little hardware

and software requirements. A detailed analysis of the effects of nonidealities leads to regional modifications of

the switching sequence resulting in almost the whole hexagon as the feasible area. The usefulness of the

proposed reconstruction algorithm has been verified by experimental results obtained from a 4-kW induction

motor drive system. Smooth transitions between the redundant and fault-tolerant modes were observed.

ETPL

PE - 99

A Three-Phase Current Reconstruction Technique Using Single DC Current

Sensor Based on TSPWM

In this study a novel modulation technique is proposed to reduce common mode leakage current in a three-

phase Z-Source inverter used in a photovoltaic (PV) system. The proposed method reduces common mode

current as well as common mode voltage (CMV); moreover, it reduces inverter output current total harmonic

distortion at high switching frequencies. At first, previously presented techniques are summarised. Then,

proposed technique is presented theoretically. Finally, conventional space vector modulation and the proposed

modulation technique are simulated for a 10 kW PV power generation system. The validity of the proposed

modulation technique is verified through MATLAB/Simulink. Simulations are performed for different load

power factors and switching frequencies with considering real application parameters to provide a certain

comparison between conventional and proposed modulation techniques. The results are analysed considering

both CMV, leakage current and inverter output current quality, and the results verify effectiveness of the

proposed technique.

ETPL

PE - 100

A novel reduced leakage current modulation technique for Z-source inverter

used in photovoltaic systems








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