IGCT-based Solid-State Circuit Breaker Coordination using Delay Compensation for DC Protection

DC microgrid systems can provide opportunities for enhanced power transfer and improved efficiency against their AC alternatives, while also posing risks like higher di/dt faults. Such hazardous scenarios demand extreme reliability from the protection systems in place. Solid-state circuit breakers (SSCBs) boast the device performance needed to meet μs-fast-tripping requirements and can allow for contained/localized fault zones by means of mutual coordination. This paper evaluates the coordination structure between six packaged breaker units, implemented using multiple SSCBs. A methodology for trip-curve approximation using delay-compensation is described, and equations illustrating individual delay elements are provided. Coordination between breakers in three possible fault scenario locations in a DC switchgear is simulated. This paper presents these modeled results before finally verifying them with experimental findings.