Short Circuit Performance and Current Limiting Mode of a Monolithically Integrated SiC Circuit Breaker for DC Applications up to 800 V

This paper presents the short circuit performance of a novel SiC circuit breaker device, which is based on the “thyristor dual” functionality. The developed device structure is motivated with regard to manufacturing aspects and electrical requirements. Furthermore, the basic “thyristor dual” operation is elaborated on the basis of quasi-static electrical measurements of a fabricated prototype. The proposed self-sensing and self-triggering devices make auxiliary circuitry like sensors and micro-controllers expendable and practically have no propagation delay. As a result, short circuit clearance within 122 ns at 800 V is demonstrated in experiments. Moreover, by utilisation of a third device terminal, a temporary current limiter functionality can be obtained. The scalability of the current limit value is discussed on the basis of measurements in time domain. The maximum current limit value achieved is 7.4 times higher than the trigger current level of the circuit breaker device. Additionally, the same circuit configuration which is used for the current limiting mode, allows to remotely reset the circuit breaker after it turned to blocking-state. This opens up a wide range of possibilities to enhance the circuit breaker with intelligent functionalities.