导电油脂对轴承电压影响的研究

Influence Research of Conductive Grease on Bearing Voltage

轴承电腐蚀一直是电机需要克服的难题,特别是对于乘用车用永磁同步电机,由于PWM控制技术的应用,直流母线电压平台和控制器开关频率的提高,使得电机发生轴承电腐蚀的风险越来越大。现结合理论分析和实验验证,对导电油脂如何影响轴承电压进行分析,以及导电油脂对轴承电腐蚀的抑制效果进行可靠性验证。研究发现:导电油脂对轴承电压的峰峰值影响较小,但能够降低轴承电压的平均值,使得轴承发生电腐蚀的概率降低,从而抑制轴承电腐蚀。以上研究具有工程实用性,可以应用并指导电机设计。

The electric corrosion of motor bearing has always been a difficult problem to overcome,especially for passenger car PMSM.Due to the application of PWM control technology as well as the increase of DC bus voltage platform and controller switching frequency,the electric corrosion risk of the bearing is increasing more and more.Based on theoretical analysis and experimental verification,this paper analyzes how the conductive grease affects the bearing voltage,and verifies the reliability of inhibition effect of conductive grease on bearing electric corrosion.It is found out by research that the conductive grease has a little effect on peak-to-peak value of the bearing voltage,but it can reduce the average value of bearing voltage and then reduce the electric corrosion probability of the bearing,so as to inhibit electric corrosion.The above research has some engineering practicability and can be used to guide the design of motors.