Research On Direct Torque Control Of Permanent Magnet Synchronous Motor Used In Vehicle Based On Fuzzy Logic

With the development of automotive electrification,motors have been widely used in various automotive systems,such as: electric drive systems,power steering systems,etc.Permanent Magnet Synchronous Motor(PMSM)has the advantages of high efficiency,high power density and high torque density,and is widely used in the automotive field.As a kind of AC motor,high-performance motor control strategy plays an important role in the performance of permanent magnet synchronous motor.Direct Torque Control(DTC)of permanent magnet synchronous motor has the advantages of simple structure and fast dynamic response,but it also has the defect of large torque ripple.In view of the large torque ripple of PMSM-DTC,this paper introduces fuzzy control to optimize DTC,and uses fuzzy control to adjust the angle,amplitude,angle and amplitude of the voltage vector to optimize the traditional direct torque control.The main research contents are as follows:A method of fuzzy adjustment voltage vector angle control is proposed.When the magnitude of the flux linkage and torque errors are different,the fuzzy output voltage vectors of different angles can realize precise control.The method for determining the optimal domain of input is given,and based on the role of zero voltage vector in fuzzy control,it is pointed out The design of the fuzzy control system should include the zero voltage vector reasonably.The simulation shows that compared with the traditional DTC,the direct torque control based on the fuzzy adjustment of the voltage vector angle can effectively reduce the electromagnetic torque ripple and improve the control performance of the system.In order to further reduce the torque ripple,a two-input fuzzy controller is designed to adjust the duty cycle of the voltage vector.In order to suppress the pulsation of the flux linkage in the power generation state of the motor and increase the flux linkage error as the input of the fuzzy controller,an improved two-input fuzzy controller is proposed to adjust the duty cycle control of the voltage vector.The simulation shows that compared with the purely refined torque and flux error levels,the fuzzy adjustment of the duty cycle of the voltage vector can obtain better control performance.The idea of cooperative control is adopted,a fuzzy controller is used to adjust the angle and amplitude of the voltage vector at the same time,the torque error and stator flux error are used as the input of the controller,and the fuzzy controller is used to output the angle and amplitude of the voltage vector at the same time.By designing the torque error membership function when the speed is negative,a fuzzy control system for adjusting the angle and amplitude of the voltage vector based on the adaptive switching of the positive and negative speed is proposed.The simulation shows that the fuzzy adjustment of the voltage vector angle and amplitude control can achieve better performance than the fuzzy adjustment of the voltage vector duty cycle control.Real-time verification of the fuzzy control algorithm based on the single-chip microcomputer platform.The fuzzy control code can be optimized by reducing the number of output sample points,sorting fuzzy rules,and pre-defined output membership arrays,without affecting the control accuracy.,Effectively reduce code running time and improve real-time performance.