Simplified fuzzy-logic-based MTPA speed control of IPMSM drive

This paper presents a simplified fuzzy-logic-based speed controller of an interior permanent-magnet synchronous motor (IPMSM) drive for maximum torque per ampere (MTPA) of stator current with inherent nonlinearities of the motor. The fundamentals of fuzzy logic algorithms as related to motor control applications are illustrated. A simplified fuzzy speed controller for the IPMSM drive has been found to maintain high performance standards with a much simpler and less computation-intensive implementation than a nonsimplified fuzzy-based algorithm. Contrary to the conventional control of IPMSM with d-axis current equal to zero, a nonlinear expression of d-axis current has been derived and subsequently incorporated in the control algorithm for maximum torque operation. The efficacy of the proposed simplified fuzzy-logic-controller (FLC)-based IPMSM drive with MTPA is verified by simulation as well as experimentally at dynamic operating conditions. The simplified FLC with MTPA is found to be robust for applications in IPMSM drives. The complete vector control scheme is implemented in real-time using a digital signal processor (DSP) controller board DS 1102 in a laboratory 1-hp IPM synchronous motor.