Permanent Magnet Synchronous Motors Vector Control System Based On Integral Sliding Mode Variable Structure With A Torque Observer

PMSM (permanent Magnet Synchronous Motors) is known for its light weight, high reliability, low loss, which is widely used in the field of motor control such as air conditioning, electric cars, compressor etc.In the PMSM control system, PI controller is typically used in traditional double closed-loop control (speed and current loop). Although PI controller has good effect on solving linear problems, it can not solve the nonlinear problem.Since the characteristics such as multi-variables, strong coupling of PMSM remains many nonlinear factors including Current coupling, parameter perturbation and external disturbances.In terms of nonlinear problem of PMSM speed control, This dissertation introduces the sliding mode variable structure control theory and the traditional design method in detail, and analyze the reasons which caused the chattering of control methods as well as solutions.designing an integral sliding mode variable structure speed controller based on an torque observer. The advantage of integral is that it is able to eliminate the noise, the advantage of sliding mode variable structure control is that it does not need the precise parameters of the system, combination with the two method’s advantage we can get higher performance when we have selected the appropriate control law and sliding mode surface at the same time a torque observer has been built which is able to realize real-time observation of load torque change. Based on the Lyapunov stability theory the stability of the structure of integral sliding mode variable speed controller and the load torque observer has been analyzed.Studying and researching the comparison with traditional PI controller in the rated speed, the load change and the system parameters on the platform of MATLAB/Simulink in view of the integral sliding mode speed controller based on variable structure PMSM observer.The simulation results show strong anti-interference ability, better robustness using the control strategy based on integral sliding mode speed torque observer.Finally, making the relevant experiment on the PMSM control system experimental platform,using TI company’s TMS320F2812 as controlling chip. The experiments results verified the feasibility and superiority of the integral sliding mode variable structure of speed control system based on PMSM torque observer presented in this dissertation.