Development of a Nonlinear Speed Controller of IPMSM Drive Incorporating MTPA with Mechanical Parameter Estimation

This paper presents a nonlinear controller based speed control of an interior permanent-magnet synchronous motor (IPMSM) incorporating maximum torque per ampere based flux control. The controller designed from standard motor model with constant mechanical parameters will lead to an unsatisfactory prediction of the performance of an interior permanent magnet motor owing to the change of mechanical parameter particularly for different load conditions. In this work, an adaptive backstepping based control technique has been developed for an IPMSM, wherein field control will be taken into account at the design stage of the controller. Thus, it is robust to dynamic uncertainties and does not require knowledge of the mechanical system parameters. The proposed controller incorporates both torque and flux controls. In addition the controller can reject any bounded immeasurable disturbances entering the system. Voltage level control inputs are designed using backstepping design methodology. The performance of the proposed drive is tested in simulation at different operating conditions, it is found that it can compensates all the electromechanical parameters variation so that no priori knowledge of real parameters is required. The robustness of the controller and its prospective real-time industrial drive application is evidenced by the results.