Research on effect of circuit parameters on breaking characteristics of mechanical DC circuit breaker

Abstract

Whether fault current can be broken quickly and reliably depends on dynamic characteristics of LC resonant commutation branch of mechanical DC circuit breaker.Thereby, the breaking characteristics of mechanical DC circuit breaker based on LC resonant commutation are studied in this paper. The topological structure and action time sequence of mechanical DC circuit breaker based on LC resonant commutation are introduced firstly. Transient voltage and transient current equations of mechanical DC circuit breaker based on LC resonant commutation are deduced on the basis. The influence of fast mechanical switch contact gap, resonant capacitor C, charging voltage of resonant capacitor C, resonant inductance L, solid-state switch turn-on time and other parameters on fault current, breaking time and other breaking characteristics are studied finally, thereby providing feasibility basis for parameter design of LC resonant commutation branch.