A cost effective hybrid circuit breaker topology for moderate voltage applications

Abstract

Compared to mechanical circuit breakers, with respect to speed and life, solid state circuit breakers based on modern high power semiconductors offers considerable advantages. During a short circuit the voltage profile of the power grid can be improved since the fault current is reduced. The distortion in voltage caused by a three-phase short circuit can be limited to fewer than 100 μs. In this paper, a theoretically approached active thyristor circuit based on a new hybrid topology of connecting the semiconductor devices in series and parallel is proposed. This permits an increase in supply voltage and fault clearance without arcing. In turn, and to get benefit from a current limitation, the circuit breaker is realized with the extinction of an electrical arc when the breaker is opened. Hence the proposed topology has led to a wider integration of solid state circuit breakers (SSCB) in existing power grids because of their cost effective nature when compared to turn-off semiconductor devices.