It fundamentally realizes the zero - current - break control for three phase contact system 基本实现同步分断（三相电流过零分断） 。
5.
1 balanced three - phase currents flowing in the three - phase symmetric winding will produce a rotating magnetic field 平衡三相电流流过三相对称绕组产生一旋转磁场。
6.
The device has considered its practical functions , which include chinese character parameter , waveform display for three - phase current , fixed value and retain of failure information 装置考虑了实用功能设计。具有汉字参数、三相电流波形显示，整定值、故障信息的保留等功能。
7.
If balanced three - phase current flow through these three - phase distributed windings , a rotating magnetic field of constant amplitude and speed will be produced in the air gap and will induce current in the rotor circuit to produce torque 如果平衡型三相电流流经这三相分布式绕组，将在气隙中产生振幅及速度稳定的旋转磁场，并会诱发电流在转子回路产生转矩。
8.
This paper introduces the three situations where the asymmetry of three - phase current takes place and proposes the calculation methods of the annexed line losses and of loss reduction when the addition of the three - phase current load is not equal to zero because of the asymmetry of the three phase load 摘要阐述了三相不对称电流的三种情况，并提出了因三相负载不对称而引起的三相电流相量之和不为零时的附加线损的计算方法及降损措施。
9.
We utilize the mutual inductor to take a sample to the three - phase current , and sample which is enlarged , rectified , filtered , is send into pic single chip microcomputer to deal with . the size of three - phase current on the line is calculated out , which offer the accurate value for the change of controls the equipment state 利用互感器对三相电流取样，然后通过放大、整流、滤波，实现交直流转换，送入pic单片机处理，计算出温室输电线上三相电流大小，为控制设备状态的改变提供精确数值依据。
10.
Wp - le series intelligent power instrument input and measurement parameter scope include : dc voltage , dc current , ac single phase voltage , single phase current , tri - phase voltage , tri - phase current , single phase active power , single phase reactive power , tri - phase active power , tri - phase reactive power , single phase active electric energy , single phase reactive electric energy , tri - phase reactive electric energy , power factor power frequency and so on Wp le系列智能电力仪表输入及测量电参数范围包括：直流电压直流电流交流单相电压单相电流三相电压三相电流单相有功功率单相无功功率三相有功功率三相无功功率单相有功电能单相无功电能三相有功电能三相无功电能功率因数cos工频频率等。
