零线电流过大

1、应用场合1. Applicable Condition 目前已大量应用于：LED显示屏、广告牌、LED路灯、景观照明、电池化成检测系统、电源生产老化系统、商场、体育馆、舞台、大型商业综合体等场所行业。Currently zero current eliminator could be used to eliminate over flow of current of zero line for LED display screen, advertising board, LED street lamp, landscape lighting, battery formatting inspection system, manufacturing and aging system of power, emporium, stadium, stage and large-scale complex etc.

2、常见造成零线电流过大的电子设备1. Electrical Equipments Which Often Encounter Zero Current Over Flowl 各种开关电源设备（计算机、电视机、显示器等）；l Various switching power equipment(computer, television, display screen etc)l 变频器的大量应用（变频空调、电机节能等）；l Equipment with mass frequency converter (inverter air conditioner, energy saving motor etc.)l 各种新光源（LED灯、节能灯、荧光灯等）；l Various new illuminants (LED lamp, energy saving lamp, fluorescent lamp etc.)l 办公设备（复印机、传真机等）；l Office equipments( duplicating machine, fax machine etc.)l 家用电器（洗衣机、显示屏、微波炉等）；l Household appliances (washing machine, display screen, micro-oven etc.)l 电子设备（手机充电器等整流设备）l electronic equipments (rectifying appliances such as phone charger etc)

3、零线电流产生的原因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).