Sliding Mode Control Of Single Stator And Double Rotor Disk Counter Rotating Permanent Magnet Synchronous Motor

With the gradual improvement of the requirements of various industries on the level of electrification,in order to meet people’s diversified and refined requirements for motors,a variety of new motor structures are emerging.In addition to the traditional DC motor,asynchronous motor and synchronous motor,various motor structures with high electromechanical energy conversion are also proposed one after another.Single stator double rotor disc counter rotating permanent magnet synchronous motor（PMSM）is composed of one stator and two rotors.The structure makes the motor compact,small volume,high power density,symmetrical electrical parameters,easy to control and so on.It is very suitable for application in places where there are space and weight restrictions on the drive system.Therefore,the motor is applied in electric vehicles,ships,torpedoes,underwater vehicles and wind power generation extensive.Dual rotor contra rotating PMSM can be regarded as two PMSMs with identical parameters in reverse series.Because the motor has only one stator and a set of three-phase windings,a set of three-phase side inverter can be used to control the two rotors to rotate in opposite direction synchronously.When a set of three-phase inverter is used to control two rotors in counter rotating PMSM,if the stator current and the magnetic field produced by the rotor are out of step,the two rotors will be out of step,and then the control system will collapse.The work and main structure of this paper are as follows:（1）This paper studies the achievements of domestic and foreign experts and scholars on the motor structure design and motor control strategy of contra rotating PMSM.By comparing the traditional PMSM theory,the mathematical model of the motor is established,which provides a theoretical basis for the control of the motor.（2）According to the existing literature,the vector control strategy based on field orientation is studied,and the model of contra rotating PMSM under the strategy is built,which verifies the accuracy of the established contra rotating PMSM model,and lays the foundation for the follow-up work.The reason of out of step of contra rotating PMSM under asymmetric load change is analyzed.The feasibility of real-time closed-loop control of corresponding rotor under different working conditions is verified through corresponding simulation experiments.The results show that the motor can operate stably.（3）Based on the above control method of real-time selection of closed-loop control corresponding rotor,the voltage feedforward decoupling control method is proposed to replace the current feedback decoupling control in traditional vector control,so as to eliminate the coupling term behind the d-q axis current,so as to remove the coupling effect caused by the speedω₁andω₂and weaken the steady-state error of the system;in order to reduce the chattering caused by traditional sliding mode,the speed loop adopts the combination of auto disturbances rejection control（ADRC）and integral sliding mode control（ISMO）to improve the global robustness of the system,suppress the overshoot and oscillation of vector control system,and improve the dynamic and steady-state performance of the system.