Research On Direct Torque Control System Of Switched Reluctance Motor Based On Active Disturbance Rejection

Switched reluctance motors have been used in various fields such as industry and life due to their low price,simple structure,high reliability and many other advantages.However,due to its own double salient structure and nonlinear saturation of the magnetic circuit,the torque ripple phenomenon is more pronounced compared with other motors,which also limits its promotion.Therefore,how to effectively suppress torque ripple has become a hot research topic in recent years.Aiming at the SRM torque ripple and the shortcomings of the traditional controller,based on the analysis of the control strategy,this thesis proposes a control method based on the combination of auto-disturbance rejection technology and improved model prediction direct torque.First of all,this thesis introduces the current development status of model predictive control,direct torque control and active disturbance rejection control,and analyzes the working principle,mathematical model and basic control strategy of SRM.Secondly,the principle of DTC is introduced.Aiming at the problem of excessive torque ripple in the SRM commutation zone and low voltage vector resulting in low control accuracy,the traditional DTC is improved by expanding the sector and increasing the voltage vector,and selecting in the commutation zone Appropriate pre-selected voltage vector avoids the introduction of negative torque,and combined with model predictive control to select the optimal vector from the pre-selected voltage vector to reduce torque ripple.Aiming at the contradiction between the system’s rapidity and overshooting that traditional PI control cannot take into account,at the same time,in order to reduce parameter setting,linear active disturbance rejection is selected as the speed outer loop controller of the SRM system to improve the system response speed and improve the system overshoot problem.Using Matlab/Simulink for simulation analysis,by comparing the simulation waveform to verify the proposed improved model predictive direct torque control can effectively suppress torque ripple.It also compares and analyzes the effects of LADRC and PI control,and verifies that the response speed is faster in the SRM system and can reduce system overshoot.Finally,TMS320F28335 is used as the main control chip to build a system experiment platform and verify system performance.The experimental results show that the improved model prediction direct torque control based on active disturbance rejection control can effectively suppress the torque ripple and improve the control effect of the system.