A Fast Acting Solid-State Circuit Breaker for Electrical Power Systems

Added capabilities for U.S. military ground, air, and sea vehicles have increased electrical power demands and the potential for extremely large fault currents. Fast and reliable means to limit fault currents and isolate faulted sections are required to meet these emerging power needs. We propose to develop an extremely fast, Silicon Carbide (SiC) based Solid State Circuit Breaker (SSCB) which is capable of high voltage, current, and power. This will allow large loads to be isolated quickly, enabling the move to greater electrical power system capacity. By also allowing greater operating temperature, our SSCB can be installed in harsh environments, such as the engine compartment, with minimal demand on vehicle thermal management systems. During Phase I, we developed and demonstrated a 1.2 kV, 200 A SSCB, and testing was completed at voltages up to 120 V, currents up to 100 A, and junction temperatures up to 185 deg C. We showed that the SSCB can isolate a fault within 2.5 microseconds, which is much faster than the 10 to 20 ms possible with electromechanical relays. During Phase II, we will continue to mature this technology by scaling the design for 500 A continuous current rating, improving current density, and demonstrating field operation in prototypical ground vehicle power system equipment.