Arcing Time of a DC Circuit Breaker Based on a Superconducting Current-Limiting Technology

Abstract

A dc circuit breaker (DCCB) based on a superconducting current-limiting technology was proposed for the interruption of short-circuit fault currents in high-voltage dc (HVDC) systems. The proposed DCCB includes a superconducting current-limiting module (SCLM), which is used to limit fault currents, and an interrupter module (IM), which uses a self-excited oscillation method to interrupt the limited current. The objective of this paper is to determine methods that reduce the arcing time of the proposed self-excited oscillation-type DCCB. The self-excited oscillation-type circuit breaker alone is generally unable to interrupt the fault current when it exceeds 8 kA. However, the proposed DCCB can interrupt a fault current of 30 kA when using the SCLM, which can limit a 30-kA fault current to approximately 3.5 kA within 2.5 ms. The arcing time of the IM was also significantly reduced as a result of the greatly reduced interrupting current. The effects of the IM parameters, including the commutation capacitance C 2 , the commutation inductance L 2 , the arc power loss coefficient N, and the arc time constant θ on the arcing time were analyzed. The arcing time can be reduced by increasing C 2 and N and reducing L 2 and θ.