A Comprehensive Review of State-of-the-Art Maximum Torque per Ampere Strategies for Permanent Magnet Synchronous Motors

Permanent magnet synchronous machines (PMSMs) have become highly favored propulsion devices due to their exceptional merits, such as high efficiency and torque density. To operate the motor and drive in an efficient region, maximum torque per ampere control has drawn a great deal of interest among loss minimization strategies. Due to the presence of high nonlinearity and sensitivity to machine parameters, MTPA control strategy requires high robustness and reliability. This paper presents a comprehensive review of the present–day technological developments related to MTPA techniques for PMSM drives. The problems associated with MTPA techniques of PMSM, such as magnetic saturation effect, cross–coupling effect, temperature effect, are systematically summarized to outline the challenges in optimal current angle searching and stator current minimization. Additionally, in terms of machine parameter dependency, the MTPA techniques of PMSM are categorized into machine parameter–dependent and machine parameter independent. Furthermore, the recent advances of MTPA techniques are assessed, and the distinctive features of different methodologies are highlighted.