Remote Power Hardware-in-the-Loop Capability Demonstrated
A new journal article by researchers at Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy Laboratory (NREL) is available online through IEEE Transactions on Industrial Electronics. Their research demonstrated a novel co-simulation architecture that uses the power hardware-in-the-loop (PHIL) technique to evaluate the impacts of emerging technologies on distribution systems, which is important for both manufacturing and utility industries.
The NREL and PNNL team demonstrated the geographically flexible architecture which provides the capability to perform remote PHIL testing—physically separating the simulation from the hardware being tested. This removes the need to convert existing grid models to a new platform or to conduct in-field trials.
Power system and power electronic applications commonly use hardware in-the-loop (HIL) simulation—to prototype, design, and test protection equipment and power electronic controllers. PHIL simulation extends this concept to power components that requite high power flows between the real component and the simulated electric circuit running on the simulator. This technique is used to test power converters, generators, etc., and involves scenarios in which the simulation environment virtually exchanges power with real hardware.
To simulate feeder-wide power flow, thermal models of houses, and stochastic patterns of other loads, a software model called GridLAB-D runs in actual time. Housed at PNNL in Richland, Wash., it supplies voltage parameters to NREL's Energy Systems Integration Facility (ESIF). In the ESIF, located in Golden, Col., two actual, residential-scale, advanced solar inverters interact with the grid simulator, reproducing the simulated points of common coupling voltages. The NREL inverters then send current measurements to GridLAB-D, updating the software distribution system model.
By increasing the understanding of interactions among multiple devices and the larger power grid, this work supports successful integration of increasing amounts of distributed energy resources, such as solar photovoltaics, electric vehicles, and demand response, into the electric power system. For electric utilities, these interactions affect distribution system reliability and operations, such as voltage regulation, power quality, protection coordination, and equipment wear. This work also helps address manufacturers’ concerns about the ability of distributed energy products to perform as designed in a wide range of real-world scenarios.