Center for Microgrid Research Assets

The St. Thomas microgrid is a real-world industry-grade microgrid housed within the Center for Microgrid Research. The microgrid is located on the University of St. Thomas campus in St Paul, Minnesota. The microgrid can operate in: (1) grid-connected mode, (2) island-mode and (3) seamlessly transition from grid-connected to island modes and vice versa. The UST microgrid is a 3 Phase, 4 Wire, 480 Volt (Vac) system. The microgrid consists of the following energy assets:

• A 48-kWdc solar Photovoltaic (PV) array on McCarthy Gym.
• A 3 Phase/480Vac Princeton Power GTIB-125 inverter converts the dc energy into ac. This inverter is capable of 0 to 1 leading/lagging power factor operation
• A 500Vdc-396 kWh Valve Regulated Lead Acid (VRLA) battery storage system. The Battery inverter is a 3 Phase/480Vac bi-directional Princeton Power GTIB-125. The inverter is capable of grid-following and grid-forming and 0 to 1 leading/lagging power factor operation
• A 3 Phase/480Vac 50-kW Cummins diesel genset (C50D6C/UC2F) controlled by Woodward EasyGen 3200XT
• A connection to Xcel Energy (utility) through a 300 kVA 13.8kV/480V substation transformer. An interconnection agreement is in place between UST and Xcel Energy.
• A 3 Phase 320kVA (0.8-1.0 power factor lagging) computer-controlled RL load controllable in steps of 1 kVA.
• Indoor and outdoor test-bays at 480/208V Three Phase and 120V Single Phase
• Relays and Protection Systems SEL 451s and RTAC 355

The Center offers utilities, industry, manufacturers and universities access to state-of-the-art lab space and cyber-physical platforms. There is no alternative for testing at full power and actual load levels before implementation.

The Center’s cyber-physical test platforms offers users the entire gamut from low-power/low-voltage all the way up to full power testing. We can help you reduce the risks of deployment and optimize the performance of microgrid hardware, communications, and security. We are happy to solve your biggest energy challenges together.

Cyber-Physical and Hardware-in-the-Loop Testing:

• Relay-in-the-Loop: Low-voltage and low-current relay testing
• Controller-in-the-Loop: Controller testing via modeling and communication
• Power-Hardware-in-the-Loop: Up to 30kVA/480Vac or 22kW/400Vdc

Full-power testing:

Built-in test bays in the microgrid allow industry partners to literally “plug-in” their systems to test near-commercial products or futureproofing current commercial products. Testing can be done at 480/208V Three Phase and 120V Single Phase up to 125 kW. Other power and voltage combinations are possible, reach out to explore possibilities.

The Center can help our industry collaborators with creating computer models of devices and testing them in real-time fashion. We can help you test software, communication, and control systems.

Hardware-in-the-Loop and Real-time Modeling Capabilities:

• Relay-in-the-Loop: Low-voltage and low-current relay testing
• Controller-in-the-Loop: Controller testing via modeling and communication
• Power-Hardware-in-the-Loop: Up to 30kVA/480Vac or 22kW/400Vdc
• Power Hardware in the Loop:
  • OPAL RT OP4510 Real time simulator
  • Ametek MX-30 30 KVA power amplifier
  • Capable of emulating different sources/loads
  • Models can be implemented in Matlab/Simulink or HYPERSIM
  • Computer Controlled Load Bank 320 kVA 0.8 Power Factor

The Center supports partnerships with state and regional companies in the development of distributed energy resources and microgrids. The microgrid is available for on-site testing, usage, or training. Many combinations of sources/loads are possible given the microgrid’s flexibility.
In addition, the Center has multiple high voltage, and power test equipment for usage by interested parties. Test equipment for pre-compliance testing of near commercial products. The Center supports distributed energy resources and microgrid software as well.

The Center supports industry partners in understanding and addressing requirements of industry standards such as: IEEE 1547-2018 and IEEE 1547.1-2020, UL 1741 and UL1741SA, IEEE 2030.7, IEC61000-3-2 and IEC61000-3-12 for Harmonic measurement, and IEC61000-3-3 and IEC61000-3-11: Voltage fluctuation / flicker measurement

Dc/ac inverters or dc-coupled devices can be tested using the Ametek TerraSAS Solar Array Photovoltaic Simulator. The simulator is rated for up to 45kWdc and up to 600Vdc. It can simulate hundreds of individual solar panels from industry-leading companies and different series/parallel array combinations. It provides high resolution I-V curve simulates static and dynamic conditions for solar insolation and temperature.

Electric-vehicle chargers, dc/ac inverters, or dc-coupled devices can be tested using the NH Research: NHR 9300 High-Voltage Battery Simulator. This simulator can be used as a battery Emulator, battery Tester, charger Emulator, charger Tester, or ultra-capacitor. The NHR9300 is a bidirectional dc source that can deliver up to 100 kW and up to 1200Vdc.

Ac and dc devices can be tested using the Ametek MX-30. The MX-30 is capable of operating in both ac and dc modes. In the ac mode, it can be a single-phase or three-phase source or load (4 quadrant). The MX-30 can operate between 0-300 Vac (Line-neutral), 16-819 Hz frequency range, and 0-1 power factor. It can deliver or absorb up to 30 kVA or 10 kVA per phase in three phase mode (10 kVA in single-phase mode). In dc mode, the MX-30 can operate between 0-400 Vdc and supply up to 3 dc outputs (20kW for 1 output or 6.5 kW per output for 3 outputs).

Other dc sources include: (1) Magna-Power TSD600-40 which can supply up to 25 kWdc and can operate between 0-600 Vdc and 0-40 Adc, (2) Magna-Power TSA 1000-10 which can supply up to 10 kWdc and can operate between 0-1000 Vdc and 0-10 Adc

Other ac sources include: (1) Pacific Power (360 AMXT – UPC32 + Mag. Module) which can supply up to 6 kVA and can be operated between 0-338 Vac (L-N) and 45-5000 Hz Freq. range

Our state-of-the-art data acquisition systems range from few Samples/sec up to GigaSamples/sec. We can help you capture and analyze data to study the performance of your device-under-test. Few examples of our capabilities:
Power Quality Analyzers and Oscilloscopes

• Yokogawa WT3000E
• Fluke 435
• LeCroy GHz 20GS/S 4 channel Oscilloscopes and Others
• High Quality Relay Oscillography
• Timestamp: GPS Antenna clock

The versatile UST microgrid can be configured as a ‘flight simulator’ to expose operators to different operational scenarios. The state-of-the-art equipment provides hands-on training opportunities in a highly controlled environment that ensures that your staff’s skills and knowledge are up-to-date. We offer private hands-on workshops and training sessions on specific equipment or the entire facility and on topics such as distributed energy resources and microgrids.