Research On Pulsation Suppression Of Direct Torque Control Of PMSM Controlled By Super-Twisting Sliding Mode Control

In order to solve the problem of the reduction of non-renewable resources,countries are continuously increasing investment and research on new energy vehicles,and the research fever of electric vehicles has been increasing year by year.Permanent Magnet Synchronous Motor(PMSM)as the core drive motor has also received widespread attention.The optimization and improvement of the motor control system can effectively improve the dynamic and static performance of the motor and improve the output performance of the motor.As we know,controlling the motor is controlling the output torque of the motor.At present,there are mainly two types of motor control strategies that are widely used: Field-Oriented Control(FOC)and Direct Torque Control(DTC).Among them,FOC is to control the output torque indirectly by controlling the current in the DC axis of the motor,and the DTC can directly control the output torque,so the implementation process is simpler.Researchers have made great progress in applying DTC to PMSM,but there are still problems to be solved,among which the main problem is the output torque ripple of the motor,which seriously affects its application in the motor controller of actual electric vehicles,so it is of great significance to optimize the research of torque ripple problem.In this paper,the DTC system of PMSM is taken as the research object,and the suppression method of torque ripple is researched.Two improvement measures are proposed.The first is the introduction of Super-Twisting Sliding Mode Control and space.Space Vector Pulse Width Modulation(SVPWM)is used to optimize the calculation of the given output torque and actual voltage output of the control system;the second is to introduce a fuzzy control theory to design a fuzzy speed PI controller to improve the speed in the original system The problem of fluctuations.Firstly,the mathematical model of PMSM is established,the basic principle of traditional DTC is analyzed and its simulation model is constructed.By analyzing the simulation results combined with the theory of DTC,the existence of traditional DTC is illustrated.The objective reason and inevitability of moment pulsation.Secondly,the control relationship between super-twisting sliding mode control principle and DTC is analyzed,and combined with the SVPWM,a DTC strategy based on super spiral sliding mode algorithm is designed,and a simulation model is constructed based on this It is verified that compared with the traditional DTC strategy,this improved control strategy can greatly reduce the torque and stator flux amplitude pulsation existing in the traditional DTC.Finally,a fuzzy speed controller was introduced to replace the traditional PI speed controller to solve the problem of speed fluctuations in the previously designed system,and simulation methods were used to verify that the original supercoil control system can reduce the torque flux fluctuations of the torque while maintaining the speed play an optimization role.