Research On AC Asynchronous Motor Speed Control System Based On Active Disturbance Rejection Algorithm

AC asynchronous motor itself is a nonlinear,strong coupling,high-order and multivariable system,and its controllability is poor.Although vector control technology can significantly improve the dynamic performance of asynchronous motor speed regulation system in theory,there are different requirements in the design of controller for different problems.In order to improve the high performance speed control technology of asynchronous motor.This paper takes the speed regulation system of asynchronous motor as the research object.Aiming at the coupling,noise and chattering problems in the actual operation of asynchronous motor model,through different control strategies,the control theories such as active disturbance rejection control and sliding mode control are applied to asynchronous motor,so as to design a new control strategy.For the operation coupling and noise of asynchronous motor,the linear active disturbance rejection controller（LADRC）is independent of the system model,which can effectively deal with the coupling between multiple parameters of asynchronous motor.At the same time,in order to improve the system performance,the structure of the linear ADRC is reconstructed to form a new control strategy to deal with the noise.The details are as follows: firstly,the error differential method is introduced into the speed loop of double closed-loop control to improve the dynamic tracking speed and anti disturbance ability.At the same time,the correction link is introduced to make up for the noise problem caused by phase lag.The mathematical analysis is carried out by using the methods of time domain and frequency domain analysis,and then the new LADRC is analyzed by using Lyapunov stability theory,Finally,the traditional and new improved controllers are verified and analyzed by mathematical simulation software.Aiming at the chattering of asynchronous motor and the chattering of sliding mode variable structure controller（SMC）,a compound control of sliding mode variable structure is proposed,which can overcome the uncertainty of the system.It has strong robustness to disturbance and unmodeled dynamics,and is suitable for the first-order system of motor speed loop.It has the advantage of simple parameter design.For this reason,this paper introduces the disturbance compensation idea of linear extended state observer（LESO）,the core of active disturbance rejection technology,and takes all the chattering of the system as the total disturbance of the system for real-time estimation and compensation,The double closed-loop compound control structure of asynchronous motor speed loop is designed.By proving the convergence of leso and analyzing the stability of SMC system,it shows that the controller not only retains the strong robustness of traditional sliding mode,but also effectively weakens the chattering problem of motor and sliding mode by taking advantage of auto disturbance rejection.Finally,the feasibility and correctness of the control strategy are verified by numerical simulation.