17 Integration of Distrubuted Generation

1 7 INTEGRATION OF DISTRIBUTED

Room 6.1

1.7 INTEGRATION OF DISTRIBUTEDGENERATIONThursday, 15th September(8 30 10 30)(8.30 - 10.30)Chair: Paola PetroniR: Stefano Massucco

171 Integration of variable generation into the grid - Scheduling aspects - P. Batra

172 Strategies and methods for the optimal integration of distributed genereration plants into the LV and MV distribution network: ENEL distribuzione experience and future prospectives - S. Botton, F. Cazzato, M. Di Clerico, D. Di Martino, F. Marmeggi

173 The distribution networks and the large diffusion of renewables power plants: the situation of Italian electric system. - S. Botton, F. Cazzato, M. Di Clerico

174 Performance evaluation of an auxiliary distributed control scheme for overvoltage mitigation - A. Mehrizi-Sani, R. Iravani

175 Active distribution networks: definition, present status of implementation and operation practices - C. D’Adamo, C. Abbey, S. Jupe, B. Buchholz, F. Pilo

176 Intelligent platform for supervision and control of distributed generation and customer demands in active distribution networks - T. Pfajfar, A. Souvent, J. Smid, M. Sepic, M. Jerele, F. Katrasnik, I. Papic

177 Monitoring and control of a smart distribution network in extended real-time DMS framework - S. Bruno, M. La Scala, U. Stecchi,

178 Active distribution networks: MV voltage profi les and loading limits for a large penetration of renewable GD - M. Cresta, F.M. Gatta, A. Geri, L. Landolfi, S. Lauria, M. Maccioni, M. Paulucci

Strategies and methods for the optimal integration of distributed generation plants into the LV and MV distributed generation plants into the LV and MV distribution network: Enel Distribuzione experience and future prospectives

Simone Botton, Fabio Cazzato, Domenico Di Martino, Marco Di Clerico, Federico Marmeggi

Enel Distribuzione SpA

CIGRE’ International Symposium, 13-15 September 2011 - Bologna (Italy)

Uso: Interno

i f i iStrategies for DG integration

MV and LV networks designed to distribute

energy from HV t k t d

Growth of DG due to high incentives

network to end users

DG NEEDED TO BE DG NEEDED TO BE CONNECTED AND

INTEGRATED TO THE DISTRIBUTION

NETWORKS

DEVELOPMENT OF DETAILED METHODS AND STRATEGIES FOR THE IDENTIFICATION OF THE STRATEGIES FOR THE IDENTIFICATION OF THE

CONNECTION SOLUTIONS TO THE NETWORK

2

Uso: Interno

h i f h i l iChoice of the connection solution

Basic principlesTechnical standards and

regulatory requirements

saturation level of the network

requirements must be fulfilled

i l d l f h krational development of the network

quality of supply

3

Uso: Interno

h i f h i l iChoice of the connection solution

Min. cost / technical acceptable criteria

A solution for the connection of a user/ producer such that the level of economic and technical works to be executed is less than other

possible connection solutions. This solution may also include works p yon existing network. This solution must also be:

TECHNICALLY FEASIBLE

ACHIEVABLE

ABLE TO ACCOMMODATE THE FULL POWER REQUIRED BY THE USER

COMPATIBLE WITH TECHNICAL AND OPERATIONAL STANDARDS IN USE

4

Uso: Interno

h i f h i l iChoice of the connection solutionCharacteristics of the DG to be connected

Detection of load / generation scenarioPlanned network

CHOICE OF CONNECTION POINT AND SCHEME

Regulatory constraints on voltage level of the connection

SOLUTION IDENTIFIED

feasibilty study

successful?YESYES

CHOICE OF ANOTHER CONNECTION POINT NONO

level of the connection

IDENTIFIEDsuccessful?

EVALUATION OF POSSIBLE NETWORK REINFORCEMENTS

EVALUATION OF NEW NETWORK

INFRASTRUCTURES

5

REINFORCEMENTS INFRASTRUCTURES

Uso: Interno

ibili diFeasibility studies

Voltage changes (slow, rapid, absolute values)

Main tests to be

performed

Network capacity

DG's contribution to fault currentsperformed DG s contribution to fault currents

Compatibility with the neutral grounding systems

Tests must be performed on a network in standard and healthy

conditions (N conditions)

For every test, network conditions to take into account and limits to consider are established

6

Uso: Interno

Feasibility studiesFeasibility studiesVoltage changes

Conditions must be fulfilled for every node of the network at the same voltage level of the connection solution

Tests are performed taking into account the worst load / generation scenarios

Test types MV network LV network

Slow voltage changes ≤ ±5% Vn ≤ ±8% Vn

Rapid voltage changes ≤ ±6% Vn ≤ ±4% Vn

Absolute value ≤ ±8% Vn ≤ ±8% Vn

7

EN 50160

Uso: Interno

Feasibility studiesFeasibility studiesNetwork capacity

Tests must check whether the contribution of DG to be connected is likely to exceed the thermal capacity of the cond cto sconductors.

Within a min load / max generation scenario, following conditions must be fulfilled:must be fulfilled:

80% Ilth on MV networks with generation and loads

100% Ilth on MV networks with only generation

60% Ilth on LV networks60% Ilth on LV networks

8

Uso: Interno

Feasibility studiesFeasibility studiesSaturation of transformers

Th fl th h th t f t t d th 90% f The power flow through the transformer must not exceed the 90% of its rated power in networks where the power flows from low to higher

voltage levels

Yearly minimum power on the transformer

( )Power expected to be injected on

the network by DG (P )(Pcmin) the network by DG (Pimm)

Pimm-Pcmin < 0,9 Pn

9

Uso: Interno

Feasibility studiesFeasibility studiesDG's contribution to fault currents

The contribution of DG in terms of fault currents must keep the values of short circuit currents in the network:

compatible with the characteristics of network breakers

compatible with the network protection system

within the limit value of I2t for the conductors

On the MV network, is checked also that the contribution of DG to the phase to earth fault current do not exceed the limits of compensation for the neutral grounding systems installed in primary substations.

10

Uso: Interno

d di d i fDG dedicated infrastructures

In order to better integrate the DG, in conditionof network’s saturation, DSO has to:

design new networks (primary substations and underlying grid) with the main purpose to collect DG

build MV networks with underground or overhead cables, in order to achieve less environmental impact and a better quality of supplyimpact and a better quality of supply

install innovative protection systems able to manage informations from DG plants

install optic fibres, in order to implement a fast and reliable communication system

11

Uso: Riservato

Thanks for your attention!

12


The distribution networks and the large diffusion of The distribution networks and the large diffusion of renewables power plants: the situation of Italian electric system

Simone Botton, Fabio Cazzato, Marco Di Clerico

Enel Distribuzione SpA

CIGRE’ International Symposium, 13-15 September 2011 - Bologna (Italy)

Uso: Interno

h l iThe Regulatory Scenario

AEEG Res. 99/08 and 179/08

(Code for Active Connections)since

1/01/2009

• MV/LV connection fees are calculated on a lump-sum basis

Big penalties to SOs

• Producers with HV or MV connection can build network plants for their connection

• Big penalties to SOs for connection delays

AEEG Res. 125/10since /

(Modification to Code for Active Connections)since

1/01/2011

• Actions to avoid opportunistic behaviour by • Actions to avoid opportunistic behaviour by “developer” of connection requests

• Introduction of “Open Season” in order to allow an organic development of the network

2

Uso: Interno

h h i l iThe Technical Scenario

Technical Scenario on distribution networks is substantially unchanged since 2008:

• Connection rules: Italian Standard “CEI 0-16”HV / MV Connection rules: Italian Standard CEI 0 16

• Approved extension to the CEI 0-16 issued by single operators

HV / MV connections

Evolution of Technical Scenario on distribution networks is in progress:

• At this time connection rules are issued by single network operators

N It li St d d t b bli h d

LVconnections

• New Italian Standard to be published

3

Uso: Interno

i fIncentives for PV

1st feed-in premium

2nd feed-in premium

3rd feed-in premium

4th feed-in premiump

2006-2007

p

2007-2010

p

Jan to May 2011

p

From June 2011

Incentives issued by 2nd feed-in premium tariff scheme were highly remunerative and can be seen as the first reason of the “DG” explosion in It lItaly.

Other factors are:

• simplified authorization procedures for renewable energy sources plantssimplified authorization procedures for renewable energy sources plants

• regulatory framework incentivizing renewable energy sources

4

Uso: Interno

l i f h i ib d iEvolution of the Distributed GenerationEnel Distribuzione Network – no. of connection requests vs

quarter of the year

6,0007,000 2007 2008 2009 2010

MV network

+ 3 400% + 3 400% 2011

quarter of the year

1 0002,0003,0004,0005,000 + 3.400% + 3.400%

fromfrom 2007 2007 toto 20102010

01,000

1° 2° 3° 4° 1° 2° 3° 4° 1° 2° 3° 4° 1° 2° 3° 4° 1° 2°

40,000

50,000 2007 2008 2009 2010

LV network

+ 1.200% + 1.200% fromfrom 2007 2007

2011

10,000

20,000

30,000 fromfrom 2007 2007 to2010to2010

5

03° 4° 1° 2° 3° 4° 1° 2° 3° 4° 1° 2° 3° 4° 1° 2°

Uso: Interno

l i f h i ib d iEvolution of the Distributed GenerationEnel Distribuzione Network

10,000 5,763 6,000

7,829

6,000

8,000

3,000

4,000

5,000

762238

698 1,034

2,142

0

2,000

4,000

1,147

292 534 730

1,453

0

1,000

2,000

MV connections per year MV connections per year [No][No]

Connected generation Connected generation power per year.power per year.

0Ante 2007 2007 2008 2009 2010 2011* Ante 2007 2007 2008 2009 2010 2011*

[ ][ ] p p yp p yMV network [MW]MV network [MW]

6

*Updated on 08.09.2011

Uso: Interno

l i f h i ib d iEvolution of the Distributed GenerationEnel Distribuzione Network

105 215

125,000 1,449 1,500

71,870

105,215

75,000

100,000

664 750

1,000

1,250

0 2,287

19,310

34,414

0

25,000

50,000

- 12 135

271

0

250

500

LV connections per year LV connections per year [No][No]

Connected generation Connected generation power per yearpower per year

0Ante 2007 2007 2008 2009 2010 2011* Ante 2007 2007 2008 2009 2010 2011*

[ ][ ] p p yp p yLV network [MW]LV network [MW]

7

*Updated on 08.09.2011

Uso: Interno

l i f h i ib d iEvolution of the Distributed GenerationOn going connection requests on Enel Distribuzione Network

31.859 MW

Total

86 852 on going requests

13.494 MW

86.852 on going requests

53.492 MW

5.884 MW

927 MW 1.328 MW

PV Wind Biomassesand biogas Hydro

Other / not renewable

78 879 4 208 2 616 822 327N b

8Updated on 12.09.2011

78.879 4.208 2.616 822 327Number

Uso: Interno

h i lTechnical Issues

Strong increase of DG is going to have a strong impact on the distribution network in terms of:

• network planning;

t ti f th t k• saturation of the network;

• operation of the network (energy dispatching and reverse flow conditions);

• system security and stability.system security and stability.

Where distribution network is going to be saturated, transmission network operator is also involved in the definition of possible network reinforcement.

9

Uso: Interno

di i b dCoordination between DSO and TSO

The spread of DG is going to have a growing impact even on National

Transmission Network 80

100

08

2009 2010

Transmission Network.

40

60

80

20

0

Revpow

e

Dedica

infrast Hconne

5 2 179

60

32

67 65 67

0

20

verse er flow

s

ated DG

tructures

HV

ections

Coordination between the DSO and the TSO needed in order to ensure

Connection requests to TSO for Connection requests to TSO for new MV/HV transformations new MV/HV transformations

dedicated for DGdedicated for DG[No vs. quarters of the year][No vs. quarters of the year]

that network security and continuity of the electrical system are not

compromised

10

compromised.

Uso: Interno

flReverse power flows – year 2010

3,500

4,000

2,500

3,000

1,500

2,000

0

500

1,000

9% 7%0

Totale sezioni AT/MT Italia

Inversione >1% Inversione >5%HV/MV transformers

Reverse flow for > 1% of a year’s time

Reverse flow for > 5% of a year’s time

11

Uso: Interno

i i lCritical Areas

As defined by Regulatory Act 125/10

14 RED (critical) areas Pimm-Pcmin>0,9*Pn

61 Orange areas

14 Yellow areas

Pimm>Pcmin

Pimm>0,5*Pcmin

18 White areas remaining areas

Plus other 590 smaller critical areas identified in non critical Provinces

Updated on 30/06/2011

Open seasons started on 01/08/2011 (3

12

p / / (months duration) only in red areas

Uso: Interno

i k b lActions taken by Enel

• Definitions of new procedural modalities for connections, in accordance with the modifications of TICA;

• revision of procedures for defining technical solutions for the connection of DG;

• definitions of new procedural modalities on how to carry on authorization processes;

• definitions of new procedural modalities on how to design and realize network installations by users, and Enel’s trial criteria;y , ;

• innovative devices and reliable communication systems to be installed in DG dedicated network infrastructures;

• pilot tests on Smart Grids infrastructurespilot tests on Smart Grids infrastructures.

n° 7 HV/MV substations alreadybuilt in the South of Italy for DGconnections.

13

Uso: Interno


14


Performance Evaluation of an Auxiliary Distributed Control

Scheme for Overvoltage MitigationScheme for Overvoltage Mitigation

Ali Mehrizi‐Sani | Reza Iravani*[email protected] | [email protected] I

Bologna CIGRE SymposiumSeptember 15 2011September 15, 2011

OutlineOutline

Motivation and Control ObjectivesMotivation and Control Objectives

P d C t l St t iProposed Control Strategiy

Results and Applications

Conclusions and Contributions

2 of 20

MotivationMotivation

Microgrid controllers should ensure thatMicrogrid controllers should ensure that– Trajectory does not violate the operational constraints– Each unit tracks its set point as closely as possibleEach unit tracks its set point as closely as possible

Existing strategies are not sufficient because microgridsO t l t th i li it d h li it d– Operate close to their limits and have limited resources

– Embed entities susceptible to overcurrents and overvoltages– Experience frequent topology changesExperience frequent topology changes– Do not possess well‐utilized characteristics of large systems

3 of 20

Proposed Strategy

A strategy to mitigate the transients of a unit to ensure

Proposed Strategy

A strategy to mitigate the transients of a unit to ensure independent and close tracking of its set point– Not based on communicationNot based on communication

4 of 20

Trajectory ShapingTrajectory Shaping

Consideration of Dynamic Limits of DevicesConsideration of Dynamic Limits of Devices

ChallengesAvoid violating dynamic limits– Avoid violating dynamic limits• With a small overshoot

– Achieve a fast response

5 of 20

• Without changing the existing controller

Proposed SolutionProposed Solution

Set Point ModulationSet Point Modulation– Improving the dynamic performance of the system without

changing existing controllersg g g

6 of 20

Proposed SolutionProposed Solution

Set Point ModulationSet Point Modulation– Improving the dynamic performance of the system without

changing existing controllersg g g

7 of 20

ApproachApproach

Introduction to the ConceptIntroduction to the Concept– Manipulating the response by temporarily manipulating the set

pointp

Unmanipulated responseUnmanipulated response

x(t)

x2

Manipulated x(t)

x2

x

x1

x2

Manipulated response

x

x1

8 of 20

Time

x2

Time

Set Point Modulation

Best Strategy


Best Strategy– Choose T1 so that the peak of the response equals the reference– Choose T2 to be the time of this peakChoose T2 to be the time of this peak

x(t)

9 of 20t


Best Strategy



x(t)

10 of 20T1 tp t


Best Strategy



x(t)

11 of 20T1 tp t


Best Strategy



x(t)

12 of 20T1 tp t


Best Strategy



x(t)

13 of 20T1 tp t

Alternate StrategyAlternate Strategy

Finite State MachineFinite‐State Machine– Manipulate the set point based on the trend of response and its

sampled valuesp

SPAACE /speɪs/: Set Point Automatic Adjustment with Correction Enabled– Based on local signals– Independent of model

Robust with respect to changes in system parameters– Robust with respect to changes in system parameters

14 of 20

Study System IStudy System I

IEEE 34 Bus Test FeederIEEE 34‐Bus Test Feeder– Added 3 DG units– Is operated in grid‐connected modeIs operated in grid connected mode

846

848

844

846

DG2

800 816 824858

834 860 836 840

842

DG3

DG2

828 830 854 852

832888 890

3

DG1

15 of 20

Case Study ACase Study A

Set Point ChangeSet Point Change– Step change for DG2 from 0.91 pu to 1.09 pu– DG1 and DG3 unchangedDG1 and DG3 unchanged

16 of 20

Study System IIStudy System II

IEEE 13 Bus Unbalanced Test FeederIEEE 13‐Bus Unbalanced Test Feeder

17 of 20

Case Study BCase Study B

Load SwitchingLoad Switching– Resistive 1 pu load switched off

1.5

0 5

1

V (p

u)

0 0.2 0.4 0.6 0.8 10.5

Time (s)

18 of 20

ConclusionsConclusions

By appropriately designing its trajectory it is possibleBy appropriately designing its trajectory, it is possible and safe for a system to operate closer to its limits.

SPAACE is effective in mitigating transients:– Step change in current: Mitigating an overshoot of 37%Step change in current: Mitigating an overshoot of 37%– Load energization: Eliminating a peak of 1.15 pu– Load de‐energization: Stabilizing oscillatory behavior of voltage– Black start‐up: Reducing the settling time by 45%

19 of 20

A ti Di t ib ti N t k D fi iti Active Distribution Networks: Definition, present status of implementation and

operational practices

Dr Samuel Jupe (Parsons Brinckerhoff)On behalf of CIGRE Working Group C6.11

Convenor: Christian D’AdamoSecretary: Chad Abbey

Session 1.7: Integration of distributed generation

Bologna, 15 September 2011 0

OverviewOverview

•Introduction•Introduction

•Global definition of active distribution networks•Global definition of active distribution networks (ADNs)

•Current status of deployment and future operational practicesoperational practices

•Stakeholder recommendations•Stakeholder recommendations

•Summary and future work


•Summary and future work

IntroductionIntroduction

W ki G C6 11•Working Group C6.11•August 2006 – August 2010•27 members and experts representing 14 countries

•Terms of Reference:•Global definition of Active Distribution Networks (ADNs)( )•Current status of deployment•Stakeholder recommendations


Shared global definition• Active distribution networks (ADNs) have systems in

Shared global definitionActive distribution networks (ADNs) have systems in place to control a combination of distributed energy resources (DERs).

• DERs are defined as generators, loads and storage.

Distribution system operators (DSOs) have the• Distribution system operators (DSOs) have the possibility of managing the electricity flows using a flexible network topology.flexible network topology.

• DERs take some degree of responsibility for system support which will depend on a suitable regulatorysupport, which will depend on a suitable regulatory environment and connection agreement.


Actual status of deploymentActual status of deployment• 24 flagship projects across the worldags p p ojects ac oss t e o d• Analysed according to:

• Integration level

• Enabling technologies

• Application

• Benefits

• Research and development needs

K fi di• Key findings: • Limited use of communications for DER remote operation


• Limited control of low voltage networks

Future operating practicesFuture operating practices

• Network operators’ priority ranking:• Network operators priority ranking:• Protection systems (Most important)y ( p )

• Safety

• Fault level management

• Communication

• Intentional islanding

A ill i i i (L t i t t)


• Ancillary service provision (Least important)

Stakeholder recommendationsStakeholder recommendations

• Grid operation• Grid operation

S t l i• System planning

• Regulatory environment

• Awareness building



• Grid operation:• Grid operation:

Re ie protection s stems• Review protection systems

• Updating Grid CodesUpdating Grid Codes

• Communication systems to support data exchange

• Mechanisms in place for grid users to provide ancillary servicesancillary services



• System planning:• System planning:

Proacti e dialog e of s stem planners ith• Proactive dialogue of system planners with stakeholders

• Consider all energy forms in system planning

• Consider move to meshed network topologies

Move to probabilistic grid based approaches• Move to probabilistic grid-based approaches



• Regulation and awareness building:• Regulation and awareness building:

Mechanisms for connection of DER• Mechanisms for connection of DER

• Allow grid operators to integrate DER into gridAllow grid operators to integrate DER into grid operations

• Educate grid users on grid operation

Feedback loop from operation to planning• Feedback loop from operation to planning


Summary and future workSummary and future work

• Overview of activities of CIGRE WG• Overview of activities of CIGRE WG C6.11:

Global definition of acti e distrib tion net orks• Global definition of active distribution networks• Actual status of deployment and future operation• Stakeholder recommendationsStakeholder recommendations

• Activities countinued in CIGRE Working• Activities countinued in CIGRE Working Group C6.19:

The planning and optimisation of active distribution• The planning and optimisation of active distribution systems, Convenor: Fabrizio Pilo


Thank you for listening!Thank you for listening!

• Full report now available:• Full report now available:

CIGRE Working Gro p C6 11 “De elopment and• CIGRE Working Group C6.11: “Development and Operation of Active Distribution Networks”, Technical Brochure No. 457, April 2011Technical Brochure No. 457, April 2011

• Any questions?Any questions?

• Contact: Samuel Jupe jupes@pbworld com• Contact: Samuel Jupe [email protected]


I t lli t l tf f i i d t l fI t lli t l tf f i i d t l fIntelligent platform for supervision and control of Intelligent platform for supervision and control of distributed generation and customer demands in distributed generation and customer demands in

active distribution networksactive distribution networks-- SUPERMEN SUPERMEN --

Tomaž Pfajfar, 2e A d j S t EIMVAndrej Souvent, EIMVJanez Šmid, Iskra MIS

Marko Šepič, Solvera LynxMarjan Jerele, Elektro Gorenjska

Franci Katrašnik, University of LjubljanaIgor Papič, University of Ljubljanag p y j j

Cigrè International Symposium THE ELECTRIC POWER SYSTEM OF THE FUTUREIntegrating supergrids and microgrids ,13-15 September 2011 - Bologna

11

Elektroinštitut Milan Vidmar, Ljubljana, SloveniaElektroinštitut Milan Vidmar, Ljubljana, Slovenia

The SUPERMEN projectThe SUPERMEN projectThe SUPERMEN projectThe SUPERMEN project

The project addresses distributed generation impacts on distribution network by implementing the concept of virtual power plant.

1. Study, development and demonstration of smart grid infrastructure.

The main objectives of the project:

2. Demonstration of basic applications for supervision and control of distributed resources and energy management.

3. To build an ICT infrastructure for further development and demonstration pof new services and applications.

The project focuses mostly on small distributed energy resources in LV and p j y gyMV distribution networks.

22


System ArchitectureSystem ArchitectureSystem ArchitectureSystem Architecture

The system consists of:

• Point-of-Common-Coupling Interfaces (PCCI)• Virtual Power Plant Control C t (VPP CC)Centre (VPP CC)

Standard protocols are used:

PCCI - VPP CC: IEC 61850VPP CC - DSO/TSO CC: IEC 60870-5-104/101, IEC 60870-6 ICCP VPP CC - users: HTTP / HTTPS (WEB services, WEB portal)

33


PointPoint ofof CommonCommon Coupling InterfaceCoupling InterfacePointPoint--ofof--CommonCommon--Coupling InterfaceCoupling InterfaceVPP CC

PCCIPCCI is used for a standardized connection ofmicro and small generation of electricity from

MiBox

IP,IEC 61850

bus,

SPA

,...

Otherdevices

micro and small generation of electricity fromdistributed resources to the distribution network.

PCCI functionalities include:• Remote monitoring and control

Mod

Modbus

Modbus

de ces

g• Power quality monitoring according to EN50160• Communication with the control center

Measuring Centre

Modbus

• Possibility of controlling compensation devices• Various protection functions

I/O Analog

44

I/ODI / DO

Analog input


Virtual Power Plant Control CentreVirtual Power Plant Control Centre softwaresoftwareVirtual Power Plant Control Centre Virtual Power Plant Control Centre softwaresoftware

The main functions of the VPP CCThe main functions of the VPP CC software:• Two-way communications with PCCinterfaces (data acquisition controlsinterfaces (data acquisition, controls, alarms)• Two-way communications with DSO’s or TSO’s control center’s systemsTSO s control center s systems (EMS/SCADA/DMS)• Applications and user interfaces for:

• DG operatorsDG operators• VPP operators

• System configuration and usermanagementmanagement• Data archiving and event logging

55

The concept of aggregation allows joint appearance on the energy and ancillary services market.


Demo system configurationDemo system configurationDemo system configurationDemo system configuration

66


ResultsResultsResultsResults

PCCI was developed using protocolIEC 61850 including two way DGIEC 61850, including two-way DGunit control and data acquisition.

Vi t l l t ftVirtual power plant software wasdeveloped using service orientedarchitecture.

The demo system was set up forfurther development and testing ofp gnew services and applications.

77


Thank you for your attention!Thank you for your attention!Thank you for your attention!Thank you for your attention!

Andrej SouventAndrej SouventEE--mailmail: : [email protected]@eimv.si

TelefonTelefon: +386: +386 ((0)10)1 474474 29032903TelefonTelefon: +386: +386--((0)10)1--474474--29032903

88

Sergio Bruno, Massimo La Scala, Ugo Stecchig , , g

Dipartimento di Elettrotecnica ed ElettronicaPolitecnico di Bari ItalyPolitecnico di Bari – Italy

Smart Grids at Politecnico di Bari This paper presents some preliminary results of an on This paper presents some preliminary results of an on-

going project on smart grids partially funded by Regione Puglia (3 years, about 1.3 M€ budget)Puglia (3 years, about 1.3 M€ budget)

It involves the Politecnico, two local energy distribution utilities (gas and electricity), and one SMEutilities (gas and electricity), and one SME

AMGAS is the local distributor for natural gas in the city of Bari (around 350 000 inhabitants and 115 000of Bari (around 350,000 inhabitants and 115,000 customers, 80,000 m3/h)

AMET is the electricity DisCo for the city of Trani about AMET is the electricity DisCo for the city of Trani, about 65,000 inhabitants and 35,000 customers

Path towards a smart distribution gridI thi th di t ib ti t i l di AMETIn this path many distribution systems, including AMET, face a tough challenge traditionally passive networks traditionally passive networks built with a straightforward radial (or multi-radial)

configurationconfiguration minimal ability of monitoring and controlling power flows

The distribution systems undergo profound modifications due to distributed energy resources (DERs), smart

t i (th d l t f t t i lmetering (the deployment of smart meters is nearly completed in Italy), storage/PHEVs It is crucial to exploit such chances derived by the naturalIt is crucial to exploit such chances derived by the natural development of the grid

In the next future…M i f ti t ICT t l More information, sensors, measurements, ICT, control resources and actuators will be available to Distribution Network Operators (DNOs)Network Operators (DNOs) allowing to implement advanced monitoring and control functionscontrol functions

SCADA/EMS (or DMS-Distribution Management System) is naturally fit for dealing with all these new elementsy g

Advanced DMS can be the core of a smart distribution grid, but most of monitoring and control tools must be re-adapted

new operative and technical requirements and availability of new control resources must be taken into account

Proposed scheme for AMETADMSADMS

• CVR: Conservative Voltage Regulation• SE: State Estimator• VVO: Voltage – Var Optimization• SMS: Storage Management System• ODPF: Optimal Distribution Power Flow

DISTRIBUTION NETWORK

RCS

ULTC

SE

• EDA: Environmental Data Acquisition• ONR: Network Reconf iguration• MMS: Maintanance Monitoring System• AR: Adaptive Relaying• CA: Contingencies Analysis

SM: Switch ManagementCVR

ADMS

Signals from RTUsSCs

DG

DGSF

DA

ODPF

ONR

VVO

AR

• SM: Switch Management• FPFS: directional Fault and Power

Failure System• SDF: Supply and Demand Forecast• TP: Topology Processor• SC: Short Circuit analysis

CA

SMS

EDA

AMR

MDI

MMS

Signals from RTUs

AMI

SCAD

°°TP

FPFS

AR

SM

• CVP: Capacitor/Voltage regulatorPlacement

• OTS: Operator Training Simulator

DISTRIBUTION NETWORK• ULTC: UnderLoad Tap Changer

SDF

CA

Real time concentrator

AMR

AMR

concentrator

SERVER

CVP

SC• RCS: Remote Controlled Switches• DG: Distributed Generation• SCs: Switching Capacitors• SF: Storage Facilities

AMI

OTS

Off‐lineEnvironmentalMonitoringStations

• MDI: Meter Data Integration• AMR: Automatic Meter Reading

GIS INTERFACE

CONTROL CENTER

Three Phase Optimal Power FlowO ti i ti d ti t l i th Optimize active and reactive control resources in the presence of unbalanced conditions (and in the extended real-time operating framework)real time operating framework)

Based on a Distribution Load Flow simulating software (OpenDSS by EPRI)(OpenDSS by EPRI)

Unbalanced conditions Object-oriented environment improved representation ofObject oriented environment, improved representation of

loads and other components Include new control variables and devices Load curtailment / active control Volt-Var Optimation (VVO)Volt Var Optimation (VVO) Conservative Voltage Regulation (CVR)

AMET distribution gridHV/MV t ti l 900 b 1000 li 500 HV/MV representation only, 900 buses, 1000 lines, 500 load nodes, 100 switches (60 controllable)

About 35 MW peak load demand About 35 MW peak load demand Scarce penetration of DERs, but fast growth of

photovoltaics (more than 60MW requested)photovoltaics (more than 60MW requested) Deployment of smart meters is 95% completed (AMI is a

proprietary system)proprietary system)Feeder

#Transfor

merImax[A]

Smax[kVA]

1 TRA 187 64702 TRA 187 6470DISTRIBUTION

SUBSTATION

SUBTRANSMISSION NETWORK

SLACK 150kV

3 TRA 187 64704 TRA 187 64705 TRB 85 29406 TRB 104 36007 TRB 85 2940

SUBSTATION

BUS B 20kV

BUS A 20kV

TR A30 MVA

TR B25 MVA

7 TRB 85 29408 TRB 187 64709 TRB 85 294010 TRA 128 443011 TRA 128 4430

FEED

ER 2

FEED

ER 4

FEED

ER 6

FEED

ER 9

FEED

ER 10

FEED

ER 11

FEED

ER 3

FEED

ER 1

FEED

ER 7

FEED

ER 5

FEED

ER 8

Load control35% l d i ti TRA d f d #3 35% load increase, congestion on TRA and feeders #3, #5 and #8

Penalty functions constraint power flows on transformers Penalty functions constraint power flows on transformers and currents on each feeder

convergence after 12 iterations about 3540 kW to be convergence after 12 iterations, about 3540 kW to be curtailed (about 8.4% of total active power)

S1 S2 I1 I2 I3 I4 I I6 I I8 I9 I10 I11iter S1[kVA]

S2[kVA]

I1[A]

I2[A]

I3[A]

I4[A]

I5[A]

I6[A]

I7[A]

I8[A]

I9[A]

I10[A]

I11[A]

0 33641 12906 157.6 159.2 193.0 149.7 90.7 89.8 38.3 109.6 45.4 133.4 101.11 33620 12903 157.5 159.2 192.9 149.5 90.7 89.8 38.3 109.5 45.4 133.3 101.02 30380 12490 142 5 153 6 176 0 132 5 82 2 90 0 38 4 105 3 45 5 115 7 85 92 30380 12490 142.5 153.6 176.0 132.5 82.2 90.0 38.4 105.3 45.5 115.7 85.93 29688 12444 139.9 152.1 173.1 129.8 82.6 89.9 38.3 104.1 45.3 113.6 83.94 29716 12457 139.9 152.1 173.2 130.0 82.8 89.9 38.3 104.1 45.3 113.9 84.2

… … … … … … … … … … … … … …10 30026 12511 140 7 152 0 173 6 132 5 84 4 89 9 38 4 103 8 45 5 116 1 86 710 30026 12511 140.7 152.0 173.6 132.5 84.4 89.9 38.4 103.8 45.5 116.1 86.711 30013 12515 140.6 152.0 173.5 132.4 84.4 89.9 38.4 103.9 45.5 116.0 86.712 30013 12519 140.6 152.0 173.5 132.5 84.5 89.9 38.4 103.9 45.5 116.0 86.8

Conservative Voltage RegulationMi i i ti f ti h d t th b t ti Minimization of active power exchanged at the substation

Load models: 50% fixed impedance model, 25% constant active power and quadratic reactive 25% linear activeactive power and quadratic reactive, 25% linear active power and quadratic reactive

Control variables: reactive power

d

iter # Ctot [p.u.] Cobj[p.u.] CV [p.u.] P1 [kW] P2 [kW]

0 13 7249 1 0000 12 7249 24544 7039outputs and tap changers setpointsA ti

0 13.7249 1.0000 12.7249 24544 70391 363.7793 0.7181 363.0612 21374 57952 27.6412 0.9848 26.6564 22174 75593 44.3911 1.1482 43.2429 24217 80964 43 7079 1 1422 42 5658 24063 8097 Active power

decrease of about 8%4 43.7079 1.1422 42.5658 24063 8097... ... ... ... ... ...15 1.2374 0.8367 0.4007 22724 635916 0.9331 0.8451 0.0881 22724 642417 0.9313 0.8443 0.0870 22712 6422

Volt-Var OptimizationI f di t ib t d i j ti l d t Increase of distributed power injections can lead to counter-flows and be cause of overvoltages

VVO aimed at constraining voltages in 1 0 1 05 VVO aimed at constraining voltages in 1.0-1.05 Control variables: reactive power outputs and tap

changers setpointschangers setpoints1,08

u.]

Before VVO

After VVO

1,08

.u.]

1,04

1,06

ge m

agni

tude

[p.u

1,04

1,06

age

mag

nitu

de [p

.

1

1,02

min

imum

vol

tag

1

1,02m

axim

um v

olta

Before VVO

After VVO

0,981 2 3 4 5 6 7 8 9 10 11

Feeder #

0,981 2 3 4 5 6 7 8 9 10 11

Feeder #

After VVO

ConclusionsS t id ll t b i ti it i d Smart grids allow to embrace innovative monitoring and control schemes

Most of approaches can be derived by standard Most of approaches can be derived by standard methodologies (OPF) that must be adapted for integrating new operative requirements and resourcesintegrating new operative requirements and resources

Smart meters are probably the most innovative contribution to smart distribution systemsy

Computation is never an issue, especially in extended real-time domain, but time requirements of the communication system can be a relevant bottleneck

The transition from simulation to implementation is the hardest step because of interoperability issues

A ti Di t ib ti N t k MVActive Distribution Networks: MV Voltage Profiles and LoadingVoltage Profiles and Loading

Limits for a Large Penetration of ts o a a ge e et at o oDG

M Cresta F M Gatta A Geri L Landolfi S LauriaM. Cresta, F.M. Gatta, A. Geri, L. Landolfi, S. Lauria, M. Maccioni, M. Paolucci

Page: 1 of 13

Paper: Active Distribution Networks: MV Voltage Profiles and Loading … Authors: M. Cresta, F.M. Gatta, A. Geri, L. Landolfi, S. Lauria,

M. Maccioni, M. PaolucciPresented by: Marco Maccioni

Outline

1 I t d ti1. Introduction2. Simulated distribution network3. Case studies4 C l i4. Conclusions

Page: 2 of 13



Introduction - 1• Nowadays, a continuously growing amount of DG has to

be integrated in MV and LV distribution networksbe integrated in MV and LV distribution networks• At individual MV network level, installed DG can cause

strongly variable bidirectional power flows on MV feedersstrongly variable bidirectional power flows on MV feeders,if it is comparable to network load

• Active MV networks pose new problems to DistributionActive MV networks pose new problems to DistributionSystem Operators:

– protective relaying– short circuit current increase– sustained feeder operation (islanding) after line dropping

l d MV d LV f d– overloads on MV and LV feeders– variability of MV and LV voltage profiles– low power factor at the interface of bulk power system

Page: 3 of 13



low power factor at the interface of bulk power system

Introduction - 2• This paper presents a parametric study on an

i ti MV t k i T i (It l ) d bexisting MV network in Terni (Italy), owned byA.S.M. Terni S.p.A., a public-owned municipal

tilitutility• Aims of the study are:

– evaluating the effect of a DG increase up to networklimits

– pointing out the factors which define the maximumallowable values of DG in operations

Page: 4 of 13



Simulated Distribution Network• 20/10 kV network owned by A.S.M. Terni S.p.A.:

three primary substations 156 MVA transformerU U

P.S . Terni Ovest

– three primary substations, 156 MVA transformercapacity612 km network extension (35% underground cables)– 612 km network extension (35% underground cables),570 MV/LV substations supplying 64000 customerswith 250 MW contractual power and 500 MWh average

G

GG

G G

G

GU U U U U

P.S . Villa Valle P .S . Ex S it

p gdaily energy demand

– loads supplied at MV level are essentiallyresidential/tertiary. Maximum load, registered in 2010,was 47 MW

– installed DG connected at MV level is about 45 MW(60% of it biomass or gas-fired thermal cycle, 36% PV,4% hydro) while 2 5 MW (PV) is connected at LV level

Page: 5 of 13



4% hydro), while 2.5 MW (PV) is connected at LV level

Case Study I – 1• Potential upper constraints for DG penetration:

maximum loading of feeders– maximum loading of feeders– alteration of voltage profiles along the feeders– increase of short-circuit currents (not considered in this study)increase of short circuit currents (not considered in this study)

• DG penetration was investigated starting from themaximum load condition and DG disconnected

• Four cases reported:– max load + 25% of DG installed– max load + 50% of DG installed– max load + 100% of DG installed

i DG ( dditi t th d f h f d f ti– maximum DG (addition at the end of each feeder of an activepower injection, up to the limits defined by constraints above)

Page: 6 of 13



Case Study I – 2• Results refer to the MV network originated by ‘Villa Valle’

PS (40 MVA 150/20 kV transformer four main MV feeders)PS (40 MVA 150/20 kV transformer, four main MV feeders)

Page: 7 of 13



Case Study I – 3Voltages and power flows at ''Villa Valle'' PS and through MV feeders

Page: 8 of 13



Case Study II – 1• Loadability evaluation carried out on a 20 kV feeder

belonging to ''Terni Ovest'' PSbelonging to Terni Ovest PS• Three line loading patterns, obtained adding at different

locations six DG blocks each rated 2 16 MW arelocations six DG blocks, each rated 2.16 MW, arecompared:

– Case A: the whole 13 MW DG installed at the end of feeder– Case B: two DG blocks installed every third of the feeder– Case C: a single DG block installed every sixth of the feeder

Page: 9 of 13



Case Study II – 2

Page: 10 of 13



Conclusions - 1• Considering steady-state constraints only, the

A S M t d t DG i fA.S.M. system can accommodate DG in excess ofnetwork load, and actually it can afford a 100 MW

fl ( di t 150 MW f MVreverse flow (corresponding to 150 MW of MV-and LV-connected DG)

• The main limiting factor in steady-state conditionsis the presence of bottlenecks in practically all thefeeders of the network

• Assuming constant active power injection by theg p j yDG, voltage profiles can be kept under control bymeans of the HV/MV transformer load tap changer

Page: 11 of 13



p g

Conclusions - 2• Because of the variable nature of several types of

DG t ti ti l l i d t l tDG, statistical analyses are required to evaluatevoltage fluctuations at MV and LV level

• The power factor seen at HV bulk delivery pointbecomes lower than 0.9 as soon as DG injectionattained 25% of planned capacity, involvingsignificant potential costs for the distributioncompany

Page: 12 of 13



Thanks for the attention!

Page: 13 of 13



Date post:	30-Apr-2017
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