Online parameter-estimation-based speed control of PM AC motor drive in flux-weakening region

This paper presents an online parameter-estimation-based high-speed control of an interior permanent-magnet synchronous motor (IPMSM) drive. The controller designed from standard linear d-q axis motor model with constant parameters will lead to an unsatisfactory prediction of the performance of an IPMSM owing to the magnetic saturation of this motor, particularly, at high-speed conditions. In this paper, an adaptive backstepping-based control technique has been developed for an IPMSM, wherein system parameter variations, as well as field control, will be taken into account at the design stage of the controller. The operating speed limit of the motor is expanded with the proposed parameter-estimation-based field control (PEFC). The complete drive is successfully implemented in real time for a laboratory 1-hp motor using digital signal processor board DS1102. The performance of the proposed drive is tested both in simulation and experiment at different operating conditions. A performance comparison of the proposed PEFC with the constant-parameter-based field control is also provided. The robustness of the controller for high-speed applications is evidenced by the results.