The Research On Anti-disturbance Control Algorithm Of PMSM Servo System

Servo system is a motion control system which ccurately follows or repeat amotional procedure. Permanent magnet synchronous motor (PMSM) has theadvantages such as small size, needless of excitation current, littler stator current andstator resistance loss, strong overload ability, etc. Vector control is an elegant controlmethod for the speed regulation of PMSM. It can simplify the motor torque controland achieve good dynamic performance. So a servo system based on PMSM vectorcontrol method is widely used in industry power system. In many cases, it needs workwith varying load and moment of inertia in many industrial scenes. Thus, a servodrive system of PMSM with strong anti-disturbance performance is necessary torestrain the effects of the disturbance factors such as load changes.Firstly, the mathematical models both in three-phase static coordinate system andtwo phase rotated coordinate system are analyzed in this paper, and a study on thecommonly used principle of PMSM vector control technology is carried. Then,combining the advanced anti-disturbance control strategy, an anti-disturbancecontroller for PMSM servo system is designed by changing the structure of PID andsetting the PID parameters.To restrain the adverse influences of the varying load and the moment of inertiabring to the performance of the PMSM servo system, combined with the AutoDisturbance Rejection Controller (ADRC) with changed PID structure, themathematical model of PMSM and the structure of the servo system control, the speedloop and position loop based on the ADRC controller are designed to realize theaccuracy of the PMSM servo system, rapid response, and robustness.With the thought of "identifying disturbances before compensating settings ", atorque observer is designed for the load torque estimation and compensation based onthe principle of the reduced-order observer. Inertia identification strategy of PMSMbased on the Gradient correction identification method is designed and the PIcontroller parameters are set through the value of identification. The improved anti-disturbance performance of PMSM servo system is achieved through settingparameters.Finally, on the basis of the work above, a set of PMSM servo control systembased on TMS320LF2812is developed, and experiments have been conducted toverify the validity of the algorithm to the disturbance.