Adaptive controller for an MTPA IPMSM drive system without using a high-frequency sinusoidal generator

A maximum torque/ampere (MTPA) interior permanent magnet synchronous motor (IPMSM) drive system that does not require a high-frequency sinusoidal generator is proposed. By using a band-pass filter, the high-frequency variation of the output mechanical power, which is proportional to the slope of torque to advance angle, can be obtained. After that, the high-frequency variation of the output mechanical power and the amplitude of the stator current vector are inputted into a fuzzy-logic controller. By using the fuzzy-logic controller, the advance angle of the MTPA for an IPMSM can be automatically determined. In addition, an adaptive speed controller is designed to improve the transient responses, load disturbance responses, and tracking responses of the closed-loop MTPA drive system. A digital signal processor, TMS-320LF-2812, is used as the control centre to execute the adaptive speed controller and the MTPA searching algorithm. Experimental results validate the correctness and feasibility of the proposed method. The proposed drive system can be applied for air conditioners, adjustable speed fans, and other industry drives.