Research On Effective Flux Linkage PMSM Direct Torque Control System Based On Active Disturbance Rejection

With the development of permanent magnet technology,the application of permanent magnet synchronous motors in the field of industrial control has become more extensive.Due to the promotion and application of electric vehicles in the market,permanent magnet synchronous motors,a high-performance power equipment,will surely become more Popular research objects.Among the various control strategies of permanent magnet synchronous motors,direct torque control has become a popular motor control research strategy due to its fast response speed and convenient control.While traditional direct torque control has many advantages,it is also accompanied by large torque ripples and changes in motor parameters at low speeds that affect the system.At the same time,direct torque control needs to rely on the stator flux linkage to calculate the electromagnetic torque,while the stator flux linkage cannot Sensors are used for measurement,and a sliding mode observer is often used to observe the stator flux.While solving the anti-disturbance ability of the motor,it has brought about an increase in stator flux chattering.In view of the problems in the direct torque control system,this thesis firstly takes the direct torque control of the permanent magnet synchronous motor as the research direction,introduces the structure and working principle of the permanent magnet synchronous motor,and establishes different coordinate systems based on the strong coupling characteristics of the motor model.Motor model,through the establishment of a traditional direct torque control system simulation model to determine the actual defects in the control process.Then,in view of the problem that the traditional flux linkage observer is particularly dependent on the motor parameters and the system is likely to cause the system to produce flux linkage chattering,the stator flux linkage observer is redesigned with the concept of effective flux linkage and the stability is proved,in order to deal with permanent magnet synchronous motors In the low-speed state,the effect of stator resistance heating is combined with the concept of active flux linkage to design the stator resistance online identification.Finally,in order to suppress the electromagnetic torque pulsation,so that the dynamic and static characteristics of the motor control system can meet the design requirements,the auto disturbance rejection control theory is introduced to improve the speed loop of the motor control system.In summary,the active flux observer and speed loop auto-disturbance rejection controller designed in this thesis can reduce the influence of motor parameters,increase the system response speed,and increase the system’s anti-disturbance ability during mathematical model analysis.This method is suitable for both built-in permanent magnet synchronous motors and surface mount permanent magnet synchronous motors.In order to verify the rationality and effectiveness of the design content,Matlab and RT-LAB semi-physical simulation platform are used for system verification.The results show that the control system has high research and application value.