Determination of the high frequency inductance profile of surface Mounted Permanent Magnet synchronous motors

Accurate knowledge of the high frequency inductance profile plays an important role in many designs of sensorless controllers for surface inductance. A special algorithm is used to decouple the cross-coupling effects between the d-axis and the q-axis, which allows mounted permanent magnet (SMPM) synchronous motors. This paper presents an AC+DC measurement method for determination of the d-axis and q-axis high frequency inductance profiles of SMPM synchronous motors. This method uses DC currents to set a desired magnetic working point on the motor laminations, and then superimpose balanced small AC signals to measure the incremental a separate determination of the d, q inductance profiles as functions of the d, q currents. Experimental results on a commercial SMPM motor using the proposed method are presented in this paper.