Impact of Position Measurement Delay Angle on Performance of PMSM Drives for Electric Power Steering in A Wide Speed Range

Permanent magnet synchronous motor (PMSM) provides the power source to electric power steering (EPS) system, which determines the steering feeling. Thus, the control performance of the PMSM drives is critical for EPS system. The position measurement delay angle plays a significant role in PMSM drives, especially when the motor rotating in the deep flux weakening (FW) region with higher speed. In this paper, impact of the position delay angle on performance of the PMSM drives for EPS in a wide speed range has been elaborated. The influence of such delay angle has been analyzed based on the voltage and current constraint boundaries of the motor in various rotation speed. Then, calibration and compensation of the position measurement delay angle have been carried out followed by. According to relative experiment results, it can be confirmed that the motor can operate stably in a wide speed range with an appropriate compensation of the delay angle. On the contrary, the motor will be out of control in deep FW region without position measurement delay angle compensation.