A scaled-down microgrid laboratory testbed

The demand for microgrids is growing rapidly since it is able to integrate distributed generation, reduce peak-load profile and transmission power losses, and increase customers´ power reliability. Microgrid infrastructures and testbeds are built or under construction globally. A 13.8-kV 4.75-MVA microgrid laboratory testbed is being built and initially tested at the University of Arkansas. However, applying and debugging new control schemes and algorithms directly in a large-scale high-power testbed poses considerable safety risks and could even damage testbed equipment. Computer-based simulations (e.g., using Matlab/Simulink^TM, PSCAD^TM) of a microgrid including several power electronic converters are time consuming and sometimes the degree of modeling may not be able to reveal some hardware experimental problems. Therefore, a low-cost, scaled-down microgrid laboratory testbed is proposed in this paper for pre-validation of new microgrid concepts before full-power implementation. Power electronic circuit hardware design, the differences with the high-power prototype and hardware test results are presented to demonstrate the feasibility and shortage of the proposed ideas.