Sensorless speed control of salient rotor PM synchronous motor based on high frequency signal injection and Kalman filter

The paper presents an approach to sensorless speed control of a salient rotor permanent magnet synchronous motor, based on a high frequency signal injection scheme improved by the use of Kalman filtering. The rotor position estimation error signal is extracted from both the d- and q-axis components of the high frequency current in the estimated rotor position reference frame. Then it is processed by a Kalman filter which yields position and speed estimates, based on a parameter independent mechanical model. The problem of carrier recovery is addressed and a simple but effective solution is presented and analysed. Realistic simulations accounting for the inaccuracy of the digital implementation are presented and discussed.