Maximum Torque per Ampere Control Algorithm for an Interior Permanent Magnet Synchronous Motor Drive Reflecting the PM Flux Linkage Variations

This paper presents a Maximum Torque per Ampere (MTPA) control algorithm for an interior permanent magnet synchronous motor (IPMSM) drive considering the PM flux linkage change due to permanent magnet (PM) temperature variation. Reluctance torque and PM torque are generated from an IPMSM and parameter variations affect development of torque, efficiency and reliability of IPMSM drives. In this paper, a PM flux linkage are estimated in real time via a Gopinath style stator flux linkage observer and a torque error correction factor is calculated from the estimated PM flux linkage. A 2-dimensional (2D) MTPA look-up table (LUT) is developed to achieve the MTPA trajectory reflecting PM flux linkage variation for compensating torque error occurred by parameter variation. The proposed IPMSM control algorithm is verified through simulations and experiments.