Research On Speed Control System Of Dual PWM Asynchronous Motor Based On Neural Network

Because of its low price,simple structure and convenient maintenance,asynchronous motor plays an indispensable role in human development.With the in-depth study of human beings,high-performance asynchronous motor speed control technology has become increasingly mature.However,in High-Performance AC speed control system,due to the large amount of calculation,complex model,non-linear components and other reasons,people need to carry out a large number of calculations on the system In practical applications,asynchronous motors often need to operate in four quadrants,such as positive and negative rotation,starting and braking.The traditional AC-DC uncontrollable DC will lead to the problem of DC bus imbalance or even high voltage burnout.In view of the above problems,this paper proposes a NARMA-L2 controller for asynchronous motor speed control system,and designs a controllable PWM rectifier circuit for the rectifier side.In this paper,firstly,the model of asynchronous motor in every coordinate system is given,and the vector control system of asynchronous motor oriented by rotor flux is studied.Based on MATLAB / Simulink platform,the vector control of induction motor oriented by rotor flux is realized.Secondly,a feedback linearization speed controller based on neural network NARMA-L2 model is designed to solve the problem of large calculation and debugging in the traditional speed controller of asynchronous motor.The neural network NARMA-L2 model is used to identify the motor,and the feedback linearization speed controller is designed based on the model.This kind of controller does not need precise mathematical model.It has good dynamic response and strong stability.Compared with the traditional PI controller,the simulation results show its superiority.Thirdly,a voltage oriented three-phase controllable PWM rectifier is designed to solve the problem of voltage instability of DC bus and the two-way flow of energy.The control circuit of the motor side is combined with the controllable rectifier circuit of the power grid side.The simulation results showthat the controllable rectifier circuit realizes the bidirectional flow of energy,the stability of DC bus voltage and the working state of the circuit maintaining at the unit factor,so that the asynchronous motor can operate in four quadrants.At last,the vector control system platform of asynchronous motor based on DSP chip is installed,the program of vector control system of asynchronous motor is written with CCS as the development software,and the experimental results show the availability about the algorithm.