利用L-C串联谐振启动大电机及无功补偿的低压开关柜

An LV Switchboard Using L-C Series Resonance Starting Large Size Motor and Reactive Compensation

一种在三相大电机的供电线路中串入谐振频率为 5 0Hz的L C串联电路 ,利用启动时L C串联电路的暂态过程较长 ,启动大电机以减小启动电流 ,而当启动完成后进入稳态 ,谐振频率为 5 0Hz的L C串联电路对于 5 0Hz的工频电流的阻抗约为 0的特点 ,实现三相交流大电机自动限流启动。启动完成后利用接触器将启动电路切除 ,将电容器切换为无功补偿电容的低压开关柜的设计原理。

Design principle of an LV switchboard was proposed.An L C series circuit of resonance frequency 50Hz was connected to power supply line of a large size three phase motor.The L C series circuit helps to reduce starting current of the machine and to achieve automatically limit current starting.The starting circuit will be removed by a contactor and the capacitor will be converted to a reactive compensation capacitor after starting.