引发中线开路的原因及危害分析

由于非线性负荷的作用,可使中线电流中含有大量的3次谐波分量.中线电流还有可能超过相线电流,使某些连接点因为发热而被烧断,造成中线开路.分析r中线开路的原因,给出了儿种常用的低压电器电流波形和谐波测试数据.对中线开路后负载电压的变化进行了计算,结果表明负荷较轻的一相会出现过电压.

Analysis on Harm and Reason of Neutral Line Open Circuit

Because of action of the nonlinear load,a large number of third harmonic component would exist in the neutral line current.Moreover,the neutral line current perhaps was bigger than the phase line current,so that some junctions temperature increased,which caused the circuit opened in neutral line,and made the neutral line break.Several common current waveforms and harmonic test datas of low voltage apparatus were given.The changes of load voltage had calculated after the neutral line opened,the results indicated that the over voltage would be produced in the phase of lower load.