Development and Implementation of a Nonlinear Controller Incorporating Flux Control for IPMSM

This paper presents a nonlinear controller based speed control of an interior permanent-magnet synchronous motor (IPMSM) incorporating maximum torque per ampere (MTPA) 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 parameters 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 parameters of the system. 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 adaptive backstepping based nonlinear controller is tested both in simulation and experiment for a 5 hp motor at different operating conditions. The results show that it can compensate all the mechanical parameters variation due to changing operating condition so that no priori knowledge of realtime parameters is required. The robustness of the controller and its prospective real-time industrial drive application is evidenced by the results.