Non-fault Detection Method Based on Additional Capacitive Control of the Resistance-Capacitance Hybrid DC Circuit Breaker

A fault identification method for the DC distribution network is proposed based on the resistance-capacitance hybrid DC circuit breaker (DCCB) with additional capacitor discharge characteristics to avoid the DC distribution network reclosing on a permanent fault. According to the topology structure of the resistance-capacitance DC circuit breaker proposed in this paper, an additional capacitor control branch is introduced, and the different working principles of the capacitor pre-charging stage, commutation stage, breaking stage, fault nature discrimination stage and Energy release stage are analyzed in detail; In the case of single-pole grounding fault, the difference in the additional capacitor voltage change between transient fault and permanent fault during the release of residual energy of the capacitor is used to realize the fault nature discrimination before reclosing. A four-terminal 10kV DC distribution system simulation model is built on the PSCAD/EMTDC platform to verify the effectiveness and correctness of the adaptive reclosing scheme through simulation and experimental analysis.