Research On Online Parameter Identification And Anti-disturbance Control Of PMSM

Permanent magnet synchronous motors have the advantages of high efficiency,large torque,and good speed performance,and are widely used in manufacturing,electric vehicles,industrial production and other fields.The permanent magnet synchronous motor is a complex system with time-varying parameters.When load disturbance or internal parameter perturbation occurs,it will affect the steady-state error,dynamic performance and speed range of the permanent magnet synchronous motor.This article takes the salient pole permanent magnet synchron.ous motor as the controlled object,and combines sliding mode variable structure control,load torque observation and moment of inertia identification to improve the anti-disturbance performance and robustness of the permanent magnet synchronous motor.The main research contents are as follows:First,the mathematical model and vector control strategy of permanent magnet synchronous motors are introduced.For traditional PI speed controllers,when load disturbances occur,there are problems such as weak anti-disturbance performance and poor dynamic response.Combined with sliding mode variable structure control methods,By improving the exponential reaching law function in the controller,a sliding mode speed controller is designed to replace the traditional PI speed controller.The results show that the proposed method can effectively improve the response speed and anti-interference performance of the system.Secondly,in view of the influence of load disturbance or internal parameter perturbation on the control of permanent magnet synchronous motor,a sliding mode load torque observer is designed,and the load torque observer is established with the speed and load torque as the observation object.The load torque value is fed forward and compensated to the torque current,and a variable gain algorithm is added.The simulation results show that the designed observer can well observe the load torque,and the use of feedforward compensation control strategy can effectively improve the robust performance of the system.Thirdly,in view of the problem that the load disturbance will cause the moment of inertia to change and cause the performance of the control system to decrease,combined with the model reference adaptive algorithm,the moment of inertia simulation model is built to identify the moment of inertia,and a variable adaptive gain algorithm is designed to improve the moment of inertia.Identification performance,reducing the influence of load disturbance on the moment of inertia identification.The simulation verifies the feasibility of the variable adaptive gain algorithm and the control system under this control strategy has better anti-interference performance.Finally,the motor-pair drag-in-the-loop simulation platform is used to verify the control strategy under different working conditions.The results show the correctness and feasibility of the control strategy proposed in this thesis,and it has good dynamic response performance and robustness.