Solid State Circuit Breakers for Microgrids
Project Innovation + Advantages:
Illinois Institute of Technology (IIT) will develop autonomously operated, programmable, and intelligent bidirectional solid-state circuit breakers (SSCB) using transistors based on gallium nitride (GaN). Renewable power sources and other distributed energy resources feed electricity to the utility grid through interfacing power electronic converters, but the power converters cannot withstand a fault condition (abnormal electric current) for more than a few microseconds. Circuit faults cause either catastrophic destruction or protective shutdown of the converters, resulting in loss of power reliability. Traditional mechanical circuit breakers are too slow to address this challenge. The team’s proposed SSCB technology offers a programmable response time to as short as one microsecond, well within the overload-withstanding capability of power converters, and enables a distribution system-level ability to isolate a fault from the rest of the power system before renewable power generation is interrupted. Their design produces a 1000x decrease in response time and 5x reduction in cost in comparison to commercial mechanical circuit breakers. If successful, such devices could be used to help protect microgrids and enable higher penetration of renewable energy sources.