Abstract:

To improve the interruption performance of DC circuit breakers in photovoltaic systems, a self-triggered hybrid DC circuit breaker(HDCCB) based on coupled inductors is proposed, which uses a miniature circuit breaker as the mechanical switch. Based on the experimentally measured arc volt-ampere characteristics, an interruption model of the proposed HDCCB is established. The coupled inductors reduce the rise rate of the fault current, thereby limiting its peak value. In addition, advancing the turn-on instant of the IGBTs shortens the overall interruption time of the circuit breaker. At high voltage levels, the voltage division and current limiting capabilities of the inductors contribute to high-capacity interruption. The results show that the proposed breaker interrupts a 15 kA current in 4.45 ms at a 1 500 V voltage level.

Key words: hybrid DC circuit breaker, self-triggered, coupled inductor, interruption time