Study of a new detection technology for sensorless PMSM drive with flux linkage observer

In this paper, a new sensorless detection scheme for PMSM is presented. This detection scheme consits of PMSM´s mathematical model and the flux-linkage observer. The mathematical model is used to approximate the nonlinear system of PMSM. Due to the current modification scheme with error-correction fashion, as detailed in this paper, the actual rotor position and the machine speed can be estimated even in the transient state, and the sensorless drive system has a good robustness to the motor parameter´s variation. The proposed detection scheme is not only to reduce the speed estimate error largely, but also to stabilize the PMSM system. The high performance of the proposed sensorless algorithm is verified by the simulation results of PMSM.