电动汽车高压母线Y电容对漏电流的影响分析

Analysis of the Influence of Y Capacitor on Leakage Current in High-voltage Busbar of Electric Vehicles

电动汽车高压部件具有很强的传导电磁干扰噪声,受电磁兼容法规的影响,大部分的高压部件都会在直流高压母线上使用可滤除共模噪声的Y电容。但多个Y电容并联在高压母线后,在整车高压上电的瞬间会产生较大的漏电流,进而影响整车的绝缘阻抗并带来安全问题。该漏电流的大小主要受高压母线电容容值、预充电阻阻值、Y电容容值等参数影响。文章通过理论计算和仿真分析,阐述各个参数之间的关系,为整车工程师设计Y电容限值提供参考依据。

The high-voltage components of electric vehicles have strong conducted electromagnetic interference noise.Due to the influence of electromagnetic compatibility regulations,most high-voltage components use Y-capacitors on the DC high-voltage busbar to filter out common mode noise.After multiple Y capacitors are connected in parallel to the high-voltage busbar,a large leakage current will be generated at the moment of high-voltage power on the entire vehicle,which will affect the insulation impedance of the vehicle and bring safety issues.The magnitude of the leakage current is mainly influenced by parameters such as the capacitance value of the high-voltage busbar,the pre charging resistance value,and the capacitance value of the Y capacitor.This article will elaborate on the relationship between these parameters,providing a reference basis for vehicle engineers to design Y capacitance limits.