Asymmetric Parameter Influence Analysis in PMSM Position Sensor Offset Error Diagnosis

The position sensor signal is a crucial measurement in field-orientation based torque-controlled permanent magnet synchronous machine-drive systems. Accurate diagnosis of position sensor faults in torque-controlled PMSM applications such as electric powertrain and electric steering systems upholds the performance of such safety-critical systems. However, varying environmental factors, manufacturing process, and aging leads to physical motor parameters varying with respect to parameters used in position sensor fault diagnosis. Such parameter variation threatens the integrity of the fault diagnosis system with false positives or false negatives. This paper investigates how such asymmetric parameter variation may influence position sensor offset error diagnosis paving the way for strategies to mitigate such false positives or false negatives. The presented analysis is supported by simulation and experimental results.