Speed characteristics of an improved feedforward compensationauto disturbance rejection control servo system
                                           JIANG Wei1, ZHANG Wenhua1, QIU Xinguo2, ZHENG Ying2
    (Key Laboratory of E&M., Ministry of Education & Zhejiang Province,Zhejiang University of Technology, Hangzhou 310014, China)

Abstract: Aiming at the problem of rotational speed performance and torque ripple of permanent magnet synchronous motor (PMSM),the effects of PMSMs speed start response characteristics, system output torque and torque ripple on the steady state characteristics of the system were studied. In order to improve the response time and speed operation of the system,a mathematical model and a motion equation of the servo system which based on the improved feedforward compensation active disturbance rejection control strategy were established,and the speed loop and the current loop control strategy were designed.By using the extended state observer (ESO),speed and system disturbance were estimated for real time and the parameter of both were corrected. And the acceleration feedforward compensation was used to compensate the disturbance of PMSM.The proportion and integral coefficient were adjusted by using the expert control idea.The Matlab was used to simulate the theoretical analysis, and the speed response time, torque output and the disturbance resistance before and after improvement were tested on the test and control machine.The results indicate that the improved control strategy can achieve fast speed response and better steadystate accuracy, making the system have stable output torque and good disturbance resistance.

Key words: permanent magnet synchronous motor（PMSM）; active disturbance rejection; parameter correction; feedforward compensation