UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
UNC-Charlotte's Power Engineering Teaching lab
B. Chowdhury
Panel Session Title: Existing and Proposed Power Systems Laboratories for the Undergraduate Curriculum
PES GM 2015
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UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Outline• Background - Energy
Production & Infrastructure Center (EPIC) and its role in education
• Innovative features of Lab• Traditional experiments• New experiments• Example experiment:
Investigating 3-phase OH line • Example experiment: Solar PV
panel characterization
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UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
EPIC and its Role
• EPIC and its role in energy education– Founded by the energy industry for workforce
development and applied research in energy– Cluster hirings (6 new faculty members hired within last
three years in power and energy)– Energy concentration – College revamping curriculum to
add an energy concentration across most disciplines.– The lab is the result of the new focus on interactive classes
and lab work– EPIC scholarships/assistantships
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UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Innovative Features
• Equipment can be configured to create exercises for– Electric machines and drives– Power systems– Smart grid concepts, microgrid management, distributed
generation, renewable energy integration, energy storage, etc.• From basic electromagnetic (fluxes and field) properties to
renewable energy-centric microgrid operation.• Individual racks may be interconnected to form full power
system models with generation, distribution and loads.• Equipment may be wheeled into the classroom for
demonstrations.
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Traditional Experiments in The Power System Laboratory
Experiment DescriptionPower measurements in R-L-C loads
Wattmeters are used to measure power in three-phase wye- or delta-connected loads.
Three-phase transformers
Three-phase transformer connections, e.g., delta-wye, wye-wye, etc. are studied. In addition, open- and short-circuit tests reveal transformer model parameters.
Generator synchronization
Synchronous generators are synchronized to the grid using different synchronizing techniques; phase sequence is examined.
P and Q control with synchronous machines
Excitation control is used to control active and reactive powers at the terminals of a synchronous machine. Over- and under-excited operations are examined.
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
New Experiments in The Power System Lab - Partial List
Experiment Description
Transmission line performance, fault studies, line protection
ABCD parameters; line performance calculations;short circuits; reactive power compensation;series/parallel connection of lines of unequal lengths.
Grid-tied and off-grid PVtechnologies
Testing the optimum tilt in response to the sun’s angle; I-V characteristics; off-grid PV system in direct power mode and storage mode; anti-islanding.
Grid-tied and off-grid windtechnologies
WT control concepts; operating at varying wind speeds; optimum operating points under changing wind conditions; response to high and low voltage “fault-ride-through”; operating off-grid wind with energy storage.
Smart grid controlExploring hybrid systems using wind and PV power in a microgrid; voltage control using SCADA; protection issues in the distribution network with DG.
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Transmission line benchFeatures:• Line length (model): 150km/300km• R, L, C representation.• May be varied.• May be loaded with R, L, C loads• Adjustable 3-phase power supply• Metering
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Transmission line model and performance
• Operate the line under no-load, surge impedance loading, and short-circuit conditions for the two line lengths to derive line performance data:– Voltage increase on open-circuit lines– Voltage drop as a function of line length– Voltage drop as a function of power factor– Capacitive and inductive power losses on a line– Phase shift on a line
• Design reactive (L and C) compensation with varying loads.• Verify system performance under symmetric and
unbalanced faults (SLG, LLG, LL) • Set protective relays (OC, distance, differential, etc.)
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Example experiment: Investigating 3-phase overhead line
• Investigate behavior of an overhead line under– no load, matched load and short circuit conditions– determine line efficiency.– Students will connect the lines to C, L and mixed
loads, and attempt to compensate reactive power in the lines.
• Determine SIL for the two line lengths– Adjust RLoad at the receiving end to match set
value of P.
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Lab station showing hardware for PV experimentation
Features:Complete system• 10-W polycrystalline solar
module• 500-W halogen lamp with
dimmer;• Three 120 VA independent solar
emulators.
• Solar charge controller• Lead-acid batteries.
• Off-grid inverter and grid-connected inverter.
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Solar PV Panel Characterization
• Experiment: Recording characteristics• In this experiment, we measure the solar module’s V/I
characteristic at various irradiances.
3 panels (emulators) can be connected in series or parallel
V
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UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Features• Rotor with three blades• Wind vane• Generator (permanent magnet
synchronous generator)• Rectifier• Slip-rings• Charge regulator or controller• Rechargeable storage battery• Inverter
Lab setup for experimenting with small wind technology
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Simple experiments at varying speeds
Objectives
• To understand the relationship between wind speed and generator power
• Exercise - Determine the generator's maximum power at wind speeds of 8, 10 and 12 m/s.– Verify that the relationship between maximum
generator power and wind speed is cubic– Verify that the load must be adjusted according to the
wind speed in order to maximize the generator power
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Lab setup for experimenting with grid-tied wind technology
Features• Wind emulator
• 1 kVA DFIG unit with two controlled inverters
• Emulation of wind and airfoil geometry
• Adjustable blade pitch
• Manual and automatic synchronization.
• Automatic control of active and apparent power, frequency and voltage
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Speed-dependent power control characteristic
Wind power characteristics (red)Theoretical curve (green )Control characteristic (blue)
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Experiment goals• Effects of pitch angle adjustment
– Operate the WT at varying wind speeds
• WT’s dynamic response in the partial load range– Determine the influence of load on speed– Determine optimal operating points for the
generator
Large wind power plant experiments
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Learning about the smart grid
• Generation coordination• Automation (sensors, controllers and
communication equipment)• Smart metering• Microgrid control• Demand response
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Features:• Smart meters SCADA Remote sensing units• Protection relays PV emulator Wind emulator• Energy storage Inverters Conventional
generation• Flexible loads
Smart grid setup
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Conclusion
• Student class projects• Senior design projects• Class demo• Lab currently serving two courses (power
systems, motors and drives)• Will be used to design a 1-hour lab course in
advanced topics in power (renewable energy, smart grid, distribution automation, etc.)
UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Other Labs – SG lab
• Smart Grid lab• 3 RTDS racks for real time simulations• Opal-RT Hypersim real-time simulator• IBM Blade server for dense data storage and real-time data
collection through gateways – Power Amplifiers & Communications– Relays, RTUs, DFRs and instruments – Data Storage & SCADA Gateways – Interoperability and Security Tools
• Used primarily for grad research and for demo to undergraduate classes
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UNC-Charlotte's Power Engineering Teaching lab
UNC-Charlotte: College of Engineering
Other Labs – Flex Lab
• Flexible power laboratory– Variable frequency / voltage research and test lab– 1.5 MVA, 480 V, 3 phase / 1200 A supply– Possible medium voltages: 12.4 kV / 200 A supply– Dielectric HV (150 kV) test bay– 690 V, 1 MVA Converter B-t-B test bay – High current (2 kA), low voltage test bed– 200 kW B-t-B Motor-Generator dyno set – Drive testing
• Will be used primarily for research and for demo to undergraduate classes
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