Research On Torque Impulse Balance Control Method Of Alternating Current Permanent Magnet Motor

In a motor speed control system, vector control(VC) can obtain a good stable control performance. Direct torque control(DTC) which is put forward based on vector control can realize quick adjustment of torque and improve the dynamic regulation performance of motor control. However, there is a PI regulator exits at the speed loop of conventional VC and DTC. The parameters of the PI regulator can make great influence on the motor dynamic performance when they can't match dynamic processes under different conditions. Therefore, this article focuses on the control method of dynamic process in order to improve the dynamic performance with conventional control method.Firstly, the mathematical model of permanent magnet synchronous motor(PMSM) is introduced in this paper and the direct torque control model is established based on it. In addition, the charge balance control(CBC) method of capacitor is also introduced. Then the electromechanical analogy is made and the relationship is established between mechanical system and electric system to provide a theoretical basis for new control theory.Secondly, torque impulse balance control(TIBC) is proposed in this paper based on DTC and CBC. This method can calculate the applied time of needed forward vector and zero vector as well as the switching time in the dynamic process of sudden load, therefore, TIBC can realize quick adjustment. The control algorithm is simplified and the torque impulse balance expression is obtained for digital control implementation of simulation and experiment.Finally, DTC and TIBC are carried out respectively on a 6/19 toothy fault-tolerant permanent magnet motor in order to validate the correctness of these theories. The mathematical model and operating principle of flux-switching permanent magnet motor(FSPM) are introduced and it is verified by Finite Element Analysis that the mathematical models of FEPM and PMSM are the same. The MATLAB models of DTC and TIBC of FEPM are established and its experimental platform is also built. Simulation and experimental results show that TIBC can achieve the fastest speed response and improve the dynamic response speed of the system.Furthermore, TIBC is expanded and the torque impulse balance expression is derived under the circumstance of sudden unload. The diagram of TIBC under VC is also established. Besides, TIBC is expanded to different motor models and its control idea is applied to power generation system.