MTPA Control of IPMSM With Self-Correction of Parameters Equivalent Base Current

Abstract

This paper describes a simple and computationally efficient maximum torque per ampere (MTPA) control method for interior permanent magnet synchronous motor (IPMSM) drives to enhance overall drive efficiency. To calculate MTPA current references accurately, a self-correction of parameters equivalent base current is developed for IPMSMs, which exhibit significant variation in flux linkage and quadrature axis inductance due to temperature and magnetic saturation, but show negligible variation in direct axis inductance during normal operating conditions. In addition, this novel MTPA control law helps to avoid the formation of memory-intensive look-up tables (LUTs), complex computation of actual motor parameters, and several types of MTPA indicators, which are widely used to deal with parameter variations for MTPA operation. Consequently, the proposed method can provide accurate MTPA current references readily and in real-time, enabling rapid MTPA control with less computational burden compared to conventional MTPA methods. Simulation and experimental results validate the simplicity, efficacy, and robustness of the proposed MTPA technique which proves to be a great alternative for implementation in low-cost industrial IPMSM drives for numerous applications.