A Surge Voltage Free Solid-State Circuit Breaker with Current Limiting Capability

Abstract

During the current interruption of the conventional DC solid-state circuit breakers, significant surge voltages are introduced across the semiconductor switches for absorbing the energy stored in the system inductance. For this reason, the semiconductor devices in the solid-state circuit breakers are required to be overdesigned in their voltage ratings, which increases the material costs and conduction losses of the breakers. Besides, to perform selective protection in DC systems, inductive reactors are installed to limit the current increment during the breaker standby phase. However, this method retards the current breaking speed of the breakers and aggravates their surge voltage issue. To address these problems, a new Surge Voltage Free Solid-State Circuit Breaker with current limiting capability has been proposed. By properly isolating its fault source, the proposed breaker can interrupt fault current with faster speed without inducing surge voltage on its switches. Furthermore, with separate energy absorption methods of system and current-limiting inductors, the proposed breaker does not trade its isolation speed for the fault current limiting capability. Simulation models along with an experimental prototype is used to prove the technical feasibility and practical value of the proposed circuit breaker.