Saliency based sensorless field- oriented control for permanent magnet synchronous machines in the whole speed range

In this paper, an approach is presented for full speed range sensorless control of permanent magnet synchronous machines (PMSM). While for small speed injection is used, the injection is switched off for high speed and the saliency information is given by the natural current ripple of the PWM. This approach uses the full model of the synchronous machine and the position information is obtained instantaneously without a filter or feedback. As the PMSM parameters are identified online, this approach provides plug and play capability.