Simulation Research On Variable-Frequency Speed Regulating System Of Asynchronous Motor Based On Vector Control

Since the asynchronous motor has the characteristics of nonlinearity,strong coupling,multivariable,and the AC speed control system has complex system structure,its control performance is influenced by the parameter changing of motor,the vector control systems based on the dynamic model of asynchronous motor are mainly studied in this paper,and fuzzy control technology is applied to improve the dynamic and static performance of speed regulating system for asynchronous motor.Firstly,the dynamic mathematical models of asynchronous motor under three-phase and two-phase coordinate system are analyzed in detail,and the basic principles of coordinate transformation and vector control are introduced in this paper.On this basis,considering the characteristics of controlled object and different control requirements,three kinds of vector control systems are designed and simulated which include slip frequency vector control system based on voltage space vector PWM(SVPWM)control technology,three phase current closed loops control based vector control system in term of rotor flux orientation,stator current excitation and torque component closed loops control based vector control system based on SVPWM control technology.Lastly,by applying fuzzy control technology,the design and simulation of three phase current closed loops control based vector control system with flux open-loop structure is completed based on fuzzy PI control.The simulation results show that the vector control systems which used the traditional controller can all get good starting performance,tracking performance and anti-interference performance,and the vector control system which applied the fuzzy PI control algorithm can effectively enhance the robustness of the control system,improve the dynamic and static performance of the speed regulating system.