1 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
2 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
3 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
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.
Traditional Experiments in The Power System Laboratory Experiment Power measurements in R-L-C loads Description Wattmeters are used to measure power in three-phase wye- or delta-connected loads. Three-phase transformers Generator synchronization P and Q control with synchronous machines Three-phase transformer connections, e.g., delta-wye, wye-wye, etc. are studied. In addition, open- and short-circuit tests reveal transformer model parameters. Synchronous generators are synchronized to the grid using different synchronizing techniques; phase sequence is examined. Excitation control is used to control active and reactive powers at the terminals of a synchronous machine. Over- and underexcited operations are examined.
New Experiments in The Power System Experiment Transmission line performance, fault studies, line protection Lab - Partial List Description ABCD parameters; line performance calculations; short circuits; reactive power compensation; series/parallel connection of lines of unequal lengths. Grid-tied and off-grid PV technologies 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 wind technologies Smart grid control 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. Exploring hybrid systems using wind and PV power in a microgrid; voltage control using SCADA; protection issues in the distribution network with DG.
Transmission line bench Features: 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
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.)
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 R Load at the receiving end to match set value of P.
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 gridconnected inverter.
Solar PV Panel Characterization Experiment: Recording characteristics In this experiment, we measure the solar module s V/I characteristic at various irradiances. I 3 panels (emulators) can be connected in series or parallel V
Lab setup for experimenting with small wind technology Features Rotor with three blades Wind vane Generator (permanent magnet synchronous generator) Rectifier Slip-rings Charge regulator or controller Rechargeable storage battery Inverter
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
Lab setup for experimenting with gridtied 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
Speed-dependent power control characteristic Wind power characteristics (red) Theoretical curve (green ) Control characteristic (blue)
Large wind power plant Experiment goals experiments 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
Learning about the smart grid Generation coordination Automation (sensors, controllers and communication equipment) Smart metering Microgrid control Demand response
Smart grid setup Features: Smart meters SCADA Remote sensing units Protection relays PV emulator Wind emulator Energy storage Inverters Conventional generation Flexible loads
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.)
20 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
21 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