Active Control of Pyrofuse in Circuit Breaker with State Estimation of Current-Limiting Fuse

Compact and cost-effective DC circuit breakers are becoming increasingly crucial as the prevalence of household solar panels and electric vehicles for a sustainable society. For this demand, a current-limiting fuse, which can limit current flow, and a pyrofuse, which physically interrupts circuits by detonating gunpowder, have been focused on as practical and compact components. This paper presents an active control of a pyrofuse in a compact circuit breaker consisting of a current-limiting fuse and a pyrofuse in series connection. The system interrupts fault currents by first limiting the current through the current-limiting fuse and then activating the pyrofuse to interrupt the circuit. The pyrofuse is activated based on a real-time estimation of the current-limiting fuse, developed in our previous research, which detects the end of the current-limiting by utilizing a real-time current data. This system safely interrupts fault currents that each component alone is unable to handle. The effectiveness of this breaker has been validated through experiments, with the interruption of a fault current of 1.7 kV and 10 kA occurring within 8.3ms.