Abstract:

A fast vacuum switch in parallel with a power electronic component containing IGCT is used in the conventional current injection DC circuit breaker to achieve the task of breaking the rated current and short-circuit current of the circuit breaker. In response to the phenomenon of commutation failure caused by the natural transfer of fast vacuum switch breaking current to IGCT power electronic components during the rated current breaking process of a single break DC circuit breaker, as well as the possibility of arc reignition at the break of the fast vacuum switch under high short-circuit current breaking conditions, an improvement design method is proposed to form a double break DC circuit breaker by connecting two fast vacuum switches in series.And the boundary capability analysis on the main parameters that affect the breaking performance of two fast vacuum switches is conducted. Through simulation and experiment verification, the double break DC circuit breaker can effectively eliminate the phenomenon of commutation failure and arc reignition, which can improve the reliability of the circuit breaker and the feasibility of practical engineering applications.

Key words: fast vacuum switch, IGCT module, double-break, commutation, arc reignited