Torque error compensation of SPMSM drives with a stator flux linkage observer including low speed operation

A compensation algorithm targeting for torque development from a surface mounted permanent magnet synchronous machine (SPMSM) including a low speed operation is presented in this paper. As known, PM flux linkage in SPMSM is varied by temperature. Because a Maximum Torque Per Ampere (MTPA) look up table (LUT), a control algorithm used for minimizing copper losses, is generated using calculated permanent magnet flux linkage, change of permanent magnet flux linkage yields torque error of a SPMSM drive. In the manuscript, estimated permanent magnet flux linkage is obtained using a stator flux observer. The torque error is corrected using the estimated permanent magnet flux linkage. The proposed algorithm is implemented and verified in simulation and experiment