Direct Tuning Strategy for Speed Controlled PMSM Drives

This paper deals with a numerical method devoted to the design of Proportional Integral (PI) controllers in Permanent Magnets Synchronous Motor (PMSM) drives. The proposed method for tuning of PI controllers is based on a suitable manipulation of the system transfer functions to achieve "closed form" expressions for the parameters of speed, torque and flux PI controllers. By using the proposed approach the designer of motor drive PI controllers would be allowed to choose both the crossover frequency and the system phase margin, yielding more flexibility in the design procedure and achieving directly the PI controller parameters as integral and proportional gains. Including non idealities, such as inverter dead-time and filtering used in current and speed real-time data acquisition, and allowing the desired phase margin to be selected, best evaluation of PI-type controller parameters is likely to be achieved, with more accurate and predictable effects on the actual motor drive performance.