Overview of Sensorless Control Strategies for Electric Vehicle Traction IPMSM

Sensorless control of electric drives can eliminate the use of position sensor during operation, thus increasing reliability and decreasing cost of the drive. Many methods have been proposed and commercialized in industrial applications such as fans, pumps and home appliances. In case of electric vehicle (EV) traction application encoder is normally used, hence sensorless control provides back-up in case of encoder failure. The aim of the paper is to provide an overview of sensorless control methods used or likely to be used on EV traction motors. Overall, EV motors have high power density and can operate under heavy saturation, thus not every sensorless method is suitable, and operating range is likely to be limited in sensorless mode. Our goal is to identify which sensorless control techniques are more suitable to be embedded in the control of EV traction motor.