Partial discharging measurement to detect early insulation damage during electrical drive unit operation

Authors

R. Cremer - FEV CRELTEC GmbH, Power Diagnostix Systems GmbH

Summary

In electrical drive units there is the risk of insulation damage at high voltage operation above 350 DC. This is getting more severe in 800 V DC applications. Increasing partial discharging (PD) in inverters and e-motors indicates in such applications weakening of insulation material. FEV CRELTEC developed a measurement system with Power Diagnostix Systems, which enables to measure partial discharging during electrical drive unit (EDU) operation. This system and its application are presented here. Based on initial defined values of partial discharging, the weakening during operation can be detected in development, in Type certification and in EOL testing as a quality level. In service with this system and method, quality can be verified in service-workshops as a preservice signal to avoid unplanned consequent vehicle repair.