Nonlinear PI controller for interior permanent magnet synchronous motor drive

This paper develops a high performance PI based controller for interior permanent magnet synchronous motor (IPMSM) drive. The performance indices which have been utilized as objective function are zero steady-state error, minimum speed deviation, and minimum settling time of the IPMSM drive. In this paper, a new method is used for tuning the PI controller. The optimal behavior of drive can be achieved by considering two control strategies: maximum torque per ampere (MTPA) control strategy in constant torque region and flux-weakening (FW) control strategy in constant power region. The nonlinear behavior of the IPMSM drives makes it difficult to tune the coefficients of the controller. This paper deals with tuning of the coefficients of the controller. In this paper a proportional-integral controller is utilized which is very simple applicable with high performance. Whereas, using the proposed tuning method, the problems that arise from conventional PI-controller, especially in nonlinear system, have been omitted.