变频冰箱引起GFCI跳闸的原因分析和解决方案探讨

Cause analysis and improvement of GFCI trip caused by refrigerator with inverter

本文研究了变频冰箱引起GFCI(接地故障电路中断器)跳闸的原因:GFCI除了对工频泄漏电流敏感外,还会对更高频率的泄漏电流敏感,这些都能够引起GFCI跳闸。变频冰箱中变频电路产生的具有高dv/dt特性的共模电压,通过压缩机驱动线在箱体内与电源线之间分布电容,以及通过压缩机定子绕组与压缩机外壳之间的分布电容,而形成高频共模电流,再流出电源线而形成很大的高频泄漏电流,触发GFCI跳闸。提出了两个对策措施,解决了GFCI跳闸的问题:其一是将箱体内的压缩机驱动线与电源线分开走线,减小耦合;其二是在压缩机舱电源线上施加滤波器。

This paper studies the cause of GFCI (ground fault circuit interrupter) trip caused by refrigerator with inverter: In addition to being sensitive to power frequency leakage current,GFCI is also sensitive to higher frequency leakage current,which can trigger GFCI trip.The common mode voltage with high dv/dt generated by the inverter circuit,through the distributed capacitance between the compressor drive line and power line,also through the distributed capacitance between the stator winding and the compressor shell,became high frequency leakage current,and GFCI tripping is triggered.Two countermeasures can solve the GFCI trip problem: One is to separate the compressor drive line and the power line in the refrigerator case.The other is to apply a filter to the power line in the compressor cabin.