Research On Torque Observation And Compensation Control Of Permanent Magnet Synchronous Motor

Compared with other motors, Permanent Magnet Synchronous Motor (PMSM) has the advantages of low inertia, high torque-current ratio, low noise, no excitation loss. Moreover, with the development of permanent magnetic materials, especially the Nd-Fe-B, PMSM has been used more and more widely.In actual operation, the performance of PMSM can be affected by various uncertainties, the greatest impact on system performance is the changes in the load torque. Sliding mode control is insensitive to parameters, and has the advantages of good robustness to external disturbance and fast dynamic response etc. So, it has been applied in motor control. In this paper, a sliding mode control algorithm based on the PMSM vector control has been proposed, and the effectiveness of the design verified by simulation.Firstly, analyzes the PMSM mathematical model at different coordinates and the conversion among them, then, build the system model for vector control. Based on these, using MATLAB / SIMULINK simulation to verify the correctness of the model.Then, designs load torque observer using adaptive control and reduced-order control, the result has been using observed by simulation.Next, based on the analysis of sliding-mode control theory and chattering, designs a load torque observer, reduces the system chattering. Designs compensation control to compensate for the speed, carries out simulation result. By the simulation results, the observer can make fast response to the changes of load torque, the chattering can be controlled well, the compensation control compensates the load torque disturbance well, improves the performance of system.At last, concludes research done in whole paper, pointed out the lack of research and some directions for improvement.