三相开关 meaning in English

three phase switch
threephase switch

Three kinds of the usual methods of rotor flux estimation are compared and analyzed , and the method of rotor flux estimation based on the voltage model is studied in detail . and the output phase voltage is reconstructed by means of the dc - bus voltage and the switching states of the inverter , the effect of the dead time and saturating voltage - drop of the switches on flux estimation is discussed . and the method of synchronizing instant speed identification is also studied deeply
本文对三种常用的转子磁链观测方法进行了对比分析，在此基础上着重研究了基于电压模型磁链观测方法，分析了利用直流母线电压和逆变器三相开关管的状态进行输出电压重构方法，讨论了死区时间和开关管饱和压降对磁链观测结果的影响，深入研究了同步瞬时转速辨识方法。