Research On PMSM Deadbeat Current Prediction Control And Current Error Elimination

In recent years,with the rapid development of control technology and manufacturing technology of permanent magnet materials,Permanent Magnet Synchronous Motor(PMSM)has been widely used in the fields of defense aviation,medical equipment,robots and automobiles because of its excellent characteristics,such as simple structure,high power factor and fast dynamic response,so the research of PMSM servo control system has important practical value and significance.PMSM servo control system is composed of position loop,speed loop and current loop,which the current loop is the core of the whole control system,and its performance directly determines the dynamic,static performance and control accuracy of the system.There are shortcomings such as slow dynamic response and large torque ripple for the PMSM control system with the current control loop as the PID mode.In this paper,the deadbeat current prediction control algorithm is studied and applied to the current loop control of PMSM servo control system.The specific contents of this paper are as follows:First of all,studying the PMSM structure and classification,coordinate transformation theory and PMSM vector control technology to lay the foundation for the simulation of PMSM servo control system;Considering sampling delay,the deadbeat current prediction control algorithm is deduced based on the mathematical model of PMSM.Designing speed loop with a PI control mode,and simulation and comparison analysis of current control loop control mode for PI control and deadbeat current prediction control to verify that the current prediction control has excellent control performance as the inner loop of the control system;Then,considering the deadbeat current prediction control algorithm is a model-based control algorithm whose control accuracy depends on precise motor parameters.The current error appears when the controller motor model parameters are inconsistent with the actual motor parameters.To eliminate the current error,the PMSM parameter estimation method based on extended EKF is proposed.This method eliminates the current error by ensuring that the controller motor model parameters are synchronized to the estimated values of the motor parameters,and the current error is eliminated;Finally,Designing hardware and software for PMSM servo control system,the hardware part mainly designs power supply circuit,three-phase bridge drive circuit,current sampling circuit and encoder circuit;The software part mainly designs the main program module,speed loop module,current loop module,and SVPWM module.In conclusion,the research of the deadbeat current prediction control improves the dynamic performancc of the PMSM control system and solves the problem of large torque ripple of the traditional vector control.The research of the current error elimination method analyzes the influence of model parameter error on the current error of the control system,and then solves that problem from the root,further improves the static performance of the deadbeat current prediction control.