Research On Cooperative Control System Of Two-motor Based On CANopen Protocol

Permanent magnet synchronous motor(PMSM)is widely used for its high efficiency,high starting torque and good stability at low speed.With the large number of long-distance and high-power transport equipment being designed and manufactured,two-motor or even multi-motor drive system has gradually become the mainstream.In the process of transportation,with the change of load,the output power of two motors in the two-motor drive system will be unbalanced,and the operation efficiency and reliability cannot be guaranteed.In addition,the long distance between two motors has a higher requirement on the communication ability of the control system.In this paper,aiming at the drive system of two-PMSM with rigid connection of output shaft and aiming at the power balance,a two-motor-drive cooperative control system is designed,and CANopen protocol communication is adopted to ensure the speed and accuracy of data transmission.The structure characteristics of PMSM are introduced.The mathematical model of PMSM in synchronous rotating coordinate system is established.The vector control scheme of i_d=0 is used to control the PMSM.The vector control simulation model is built,and the simulation results show that the model has good speed and torque control effects.The torque deviation coupling control strategy is proposed for the two motor drive system with rigid connection of output shaft to realize the power balance of two PMSMs.The architecture of CAN bus communication and its application layer protocol CANopen are analyzed.Hardware configuration for the master station controller.Based on CM CANopen module,a master-slave communication program is programmed to realize the communication between master station controller and permanent magnet synchronous motor driver.The control program of the two-drive cooperative control system is designed,including the start-stop control program,cooperative control program,compensation program of given speed and protection program.By calling different subroutines to achieve the required functions of the system.The monitoring interface of the upper computer is designed to realize the remote monitoring and automatic control of the two-driven cooperative control system.The experimental platform of two-motor drive system was built.The influence of given speed difference on the output torque of two motors is verified by experiments.The experiment of load mutation is carried out,and the results show that compared with the system using parallel control scheme,the two-motor-drive cooperative control system can adjust the torque difference of the two motors to 10%rated torque within 0.5s,and it has better power balance effect.The failure simulation test results show that the system has high security.The two-motor-drive cooperative control system was applied to the mine scraper conveyor and the field test was carried out.The results show that the designed control system has better practicability.