Study On Modular Series Vacuum Circuit Breaker

In this paper, a kind of modular series vacuum circuit breaker is presented after the analysis of the multi-break vacuum circuit breaker in the background and research status at home and abroad. The multi-break vacuum circuit breaker is designed by multiple modular vacuum switch unit connected in series. This novel multi-break vacuum circuit breaker can improve the voltage level significantly. The control unit for modular vacuum circuit breaker use optical fiber technology, which can be used in the low potential terminal and control the electronic operation mechanism of the circuit breaker. Bistable state permanent magnetic mechanism is chosen as the operating mechanism. The structure of double-break vacuum circuit breaker can be designed as T, Y, double column type or vertical type. U type, vertical parallel type and vertical type arrangement is used for triple-break vacuum circuit breaker.Electromagnetic transient analysis software platform, ATP is used to set up a simulation platform for the multi-break vacuum arc model. Simulation is operated with voltage sharing capacitor and without voltage sharing capacitor to interrupt the fault current. Based on the results of the simulation, under the condition of power frequency voltage and large current, multi-group experiments are compared. The experiments contain multi-break vacuum circuit breaker interrupt simultaneously and asynchronously, each break interrupt with and without the voltage sharing capacitor, each break interrupt with different value voltage sharing capacitor. Compared with the simulation results, the significant factors for breaking capacity of the multi-break vacuum circuit breaker depend on the simultaneously interrupt of the operating mechanism and the voltage sharing between the two breaks. Therefore, the operation mechanism need low dispersion design, and the voltage sharing capacitor need to choose appropriately. These two factors will become to significant factors for vacuum circuit breaker break successfully. For double-break vacuum circuit breaker, when voltage sharing capacitor is more than the certain value, the equalizing effect is not obviously changing with the capacitor value. Considering economic operation, the experiment model uses1000pF to2000pF capacitor value as the double-break vacuum circuit switch capacitance.