1、零线电流产生的骒貉缭塄原因1. The cause of zero line current occuring根据国家标准GB17625.1-2003《电磁兼容 限值 谐波电流发射限值(设备每相输入电跽啻猢崇流≤16A)》限值要求,对以上设备谐波限值很低,造就产品3次谐波含量很大,由于3次谐波矢量方向角度一致,使用寿命次谐波向零线叠加,造成零线电流过大,。单体功率极少,单体而言,造成的危害可以忽略不计,但当相当多的单体一起使用时,零线电流大得惊人(严重时超过相线电流的两倍)According to limit value stipulated by national standard GB17625.1-2003 “Electromagnetic compatibility--Limits--Limits for harmonic current emissions(equipment input current≤16A per phase)”, the harmonic current limit value regulated for above equipment stated under item 3 is very low, it makes the 3rd order harmonic current capacity large, also because the 3rd order harmonic current is consistent in vector, direction and angle, the working life of sub harmonic current overlay to zero line, these makes the current of zero line over flow. Power capacity of single equipment is low and we could ignore its damage, but when a great amount of equipments are used at the same time, current of zero line will be great (it will be more than twice of the phase line in serious situation).