Improved Rotor Position Estimator with a New Inductance Estimation Method for IPMSM Sensorless Drive

This paper proposes a novel inductance estimation method based on a signal injection to improve a position error estimation performance of sensorless control by using a rotation matrix for interior permanent magnet synchronous motor. Using the rotation matrix method for estimating a rotor position error has advantages as wide estimation range and satisfy with linearity of the position error. However the estimated position error is calculated from voltage value containing model based inductance value that when the model based inductance are different from the real motor inductance, the estimated position error will be inaccurate. In order to obtain the accurate motor inductance value for an accurate position error, this paper proposes a novel inductance estimation method which is possible to independently identify d-axis and q-axis inductance in offline and online. Through simulation results, the effectiveness of the proposed inductance estimation method is verified.