Research On PMSM Sensorless System Based On BackStepping Adaptive Control

With the characteristics of simple structure, reliable running, small size, light weight, high efficiency, high energy density, Permanent magnet synchronous motor (PMSM) has good prospects in industrial and agricultural production, aerospace and national defense. Nowadays, the research on the control of PMSM is a hot research topic. Based on the PI control strategy and location sensor, traditional PMSM control system has some shortcomings, such as high cost, decreased robustness and heavy reliance on running environment, thus novel control methods which can overcome these problems should be researched.Since the model of PMSM is nonlinear, strongly coupled and time variable, a backstepping adaptive control method of PMSM is proposed. First a linear reference model is used to give the performance evaluation of the control system. By defining the virtual control and applying Lyapunov stability theory, the stability of the system can be guaranteed. Then the control law and parameter updating law are derived. For fault of traditional drive system, such as relying on high-precision sensor, this thesis studies on the sensorless technology. Compared with traditional position or speed sensor control system, a novel sliding-mode speed observer is introduced in the thesis. With electromotive force estimated by S-type functions, the chattering caused by high frequency switching control can be decreased in the presented control system. The rotor position and speed can be observed eventually.The simulation model for the control system above is established and the performance of the whole system is analyzed. The results show that the system achieves high dynamic performance and good robustness.