Analysis and Quantification of Position Sensor Offset Error in Feedforward Controlled PMSMs

Abstract

Permanent Magnet Synchronous Machines (PMSM) are popular in transportation electrification applications due to their inherent torque density and ease of control. In torque control applications, field-oriented control (FOC) ensures optimal torque production. However, PMSMs require a rotor position information for FOC, achieved with sensors such as encoder, resolver or linear hall sensor. Feedforward controlled FOC being one key form of PMSM control, the position sensor signal accuracy is paramount. Due to the harsh environments experience by systems in the transportation segment, the position sensor has the potential to misalign from the initially calibrated alignment. This paper focuses on the effects of such position sensor misalignment on feedforward-controlled drives. A novel quantification strategy to detect the failure mode has been presented with analytical details. The methodology is verified through simulation and validated by experimental results. Moreover, a brief analysis-contrasting the effects of position sensor misalignment on feedback and feedforward-controlled drives are presented.