Research And Design Of Double PMSM Speed Synchronous Control System

With the continuous development of technology and modern industry,the double permanent magnet synchronous motor(PMSM)drive system has the advantages of high power and high efficiency.It is more and more widely used in industrial applications such as electric vehicles,robots,shipborne guns,and well lifts.However,if the speeds of the two motors are not synchronized,it can cause serious problems easily such as large mechanical loss and shaft fatigue.Therefore,improving the speed synchronization accuracy has important research significance and application value for dual-motor control.This article completes the mathematical model of permanent magnet synchronous motor,comparison of common speed synchronization control algorithms,improvement of cross-coupling control algorithm and experimental verification,etc.The specific content is as follows:(1)Establish the mathematical model for permanent magnet synchronous motor,and introduce the space vector pulse width modulation(SVPWM)technology.Verify the validity and feasibility of the model through MATLAB/Simulink.The simulation results show that:SVPWM technology has high voltage utilization rate and the single-motor system has fast response speed.This can make the foundation for the follow-up dual-motor speed synchronous control.(2)For the problems of the traditional dual-motor mechanical structure synchronization method,the structure is complicate and easy to wear.Research is carried out for electric synchronous speed control method with simple mechanical structure.Four speed synchronization control structures of parallel,master-slave,virtual spindle,and cross-coupling are established.Finally,four speed synchronization control algorithms are verified via Simulink.The speed synchronization time and synchronization error of the four electrical synchronization methods are compared with load and load added suddenly.The simulation results show that: by adopting a cross-coupling structure and selecting an appropriate coupling coefficient,the system has better speed synchronization performance.(3)For the problems that it takes a long time for the dual motors to reach a given speed when starting with a load and the dual-motor speed synchronization error is large,the recovery time is long when the load is applied suddenly in dual-motor control,this paper designs a variable reaching law sliding mode cross-coupling control algorithm.Add variables for improvement on the basis of the exponential approaching law.Design the speed synchronous compensator under the cross-coupling structure.Then compare with traditional PI cross-coupling algorithm and ordinary cross-coupling algorithm.Dual-motor simulation models with three different algorithms are built.Simulation results show that: The algorithm in this paper has high speed synchronization accuracy and small synchronization error time when start with load and load applied suddenly.(4)The physical platform of the dual-motor speed synchronous control system is designed,including dual-motor system mechanical structure,drive board,dual-motor control software.Transplant the variable reaching law cross-coupling algorithm into the program.The experimental results show that the dual-motor physical system can get the expected requirements of the simulation results.