By analyzing the current researches of high voltage vacuum switch
the necessity and feasibility to research and develop 126 kV double-break vacuum circuit breaker are demonstrated
and some countermeasures are presented against the defects of the conventional double-break vacuum switch.Consequently
a new type of 126 kV double-break vacuum circuit breaker is proposed
and theoretical analysis illustrates its better voltage distribution in each break to avoid the adverse influence of voltage-sharing capacitance in parallel with each break.A permanent magnetic actuator with high moving precision is applied to the double-break vacuum circuit breaker to ensure the synchronization of double-break action.