Design and Experimental Verification of an Efficient SSCB Based on CS-MCT

A novel solid state circuit breaker (SSCB), which uses the cathode-short MOS-controlled thyristor (CS-MCT) as the main switch to achieve high power efficiency, is proposed for direct current (dc) microgrid protection. The proposed SSCB features the commutating circuit with a one-shot triggering characteristic and a compact size, which makes the SSCB realize a simple tripping process and easy integration. Furthermore, the SSCB charges the commutating capacitor and offers the interruption capability before the main switch is turned on. This avoids the possible failure of the breaker under the fault that occurs at the initial stage of the turn-on of the main switch, thus providing highly reliable and robust interruption capability for the SSCB. Circuit analysis and design guidelines are discussed in detail through the mathematical modeling. Moreover, the practical value and the feasibility of the SSCB are validated by 600-V/15-kW prototype experiments and further verified in dc microgrids through simulations.