Experimental Challenges in Maximum Torque Per Ampere Control of Indigenous Interior Permanent Magnet Synchronous Machine and its Solutions

This paper presents the experimental implementation of Maximum Torque per Ampere (MTPA) control for an Interior Permanent Magnet Synchronous Motor (IPMSM) developed indigenously, where knowledge of motor parameters was initially lacking. The paper discusses the resolution of various challenges encountered in IPMSM speed control. These challenges include limitations imposed by high direct axis inductance ($\mathrm{L}_{\mathrm{ds}}$) and quadrature axis inductance ($\mathrm{L}_{\mathrm{q}}$) on per phase stator voltage, which restrict the motor’s speed and loading capacity below levels specified by the manufacturer. Additionally, the paper addresses issues related to motor starting and the intricate implementation of the MTPA algorithm in a DSP microprocessor. The strategies adopted to overcome these challenges are discussed, and experimental results are provided to illustrate the efficacy of the implemented MTPA control strategy.