Study on effect of voltage distortion on insulation of variable-frequency adjustable-speed traction motor

Voltage distortion accelerates insulation aging of variable-frequency adjustable speed traction motor. The paper focuses on analysis of accelerating thermal, mechanical and electrical aging process caused by distortion. A simulation system, including variable-frequency power sources and direct self-controlled (DSC) traction motor, has been set up. With this system, the distortion of power sources influenced by parameters of inverter power source and operating condition has been studied, which makes it possible to take insulation deterioration into consideration while setting DSC parameters. Also, insulation deterioration of traction motor resulted from voltage distortion are discussed, which gist for insulation design. Finally, this work would offer basic theory for research of insulation destruction mechanism of variable-frequency motor.