Measurement and discussion of inductance distortion caused by magnetic saturation for sensorless control of IPMSM

This paper considers the inductance spatial distribution of Interior Permanent Magnetic Synchronous Motors (IPMSM) in various load conditions. The IPMSM machine possess a unique relationship between phase inductance and rotor position, that make it possible to implement sensorless control by extracting rotor position information from the inductance distribution. During the past two decades, many sensorless control methods for IPMSM drive based on magnetic saliency have been proposed. However, the inductance varies with the load conditions and the motor structure, which causes the sensorless control performance to be degraded. This paper reports on a high-frequency voltage signal injection method of measuring the phase inductance, and focuses discussion on the inductance spatial distribution including magnetic saturation.