Accuracy improvement of maximum torque per ampere control for interior permanent magnet synchronous motor drives reflecting PM flux linkage variations

An algorithm for an interior permanent magnet synchronous motor (IPMSM) drive to improve the accuracy of maximum torque per ampere (MTPA) control reflecting variations in the permanent magnet (PM) flux linkage is proposed in this paper. In IPMSM drives, reluctance and PM torque are generated, and both the efficiency and developed torque of IPMSM drives are directly affected by parameter variations. A stator flux linkage observer estimates PM flux linkage in real time, and a correction factor for torque error compensation is computed. The MTPA trajectory is formed into a two-dimensional look-up table (LUT), which is used to allow the MTPA trajectory to correct the torque error caused by parameter changes. In this paper, the proposed torque error compensation IPMSM control method is implemented and confirmed by simulation and experimental results.