DSOGI Based Rotor Position Estimation for DTP-PMSM Considering DC Bias

The traditional position observer is susceptible to DC bias caused by measurement error and parameter change in sensorless control at medium and high speed. Therefore, an improved flux observer based on bisecond-order generalized integrator is proposed in this paper. By constructing a specific harmonic current feed quantity in the harmonic subplane and using a double second-order generalized integrator (DSOGI) to get the feedbacks of the injected current, the DC bias error caused by sampling error and motor parameter change is eliminated. Finally, the feasibility and effectiveness of the proposed observer are verified by taking the two-three-phase permanent magnet synchronous motor as an example.