Research On Control Strategy Of Networked AC Asynchronous Motor Control System

With the rapid development of network communication technology and computer technology,network control systems have been applied in many different fields.The networked AC asynchronous motor realizes data transmission by the communication network,thereby realizing the control of the AC asynchronous motor.Compared with the traditional control method,the control method of the networked AC asynchronous motor has more advantages.However,the introduction of the traffic network into the control system will inevitably lead to problems such as network induced time lag,which will worsen the stability of the control system and even make the system unstable.Therefore,the influence of AC asynchronous motor on its control performance and the nonlinear problem of AC asynchronous motor are urgently needed to be solved.Combining the network control system analysis methods and the AC asynchronous motor decoupling control method,the research on the networked AC asynchronous motor control system modeling and system control strategy has a very broad prospect and application for realizing the high performance control of AC asynchronous motor under network conditions.value.The main research results of the thesis are as follows:(1)Establish a mathematical model of AC asynchronous motor.In order to solve the nonlinear problem of AC asynchronous motor,a linear decoupling method is adopted,and the mathematical model of networked AC asynchronous motor is established based on the characteristics of the network.The mathematical model of discrete networked AC asynchronous motor with controller parameter perturbation and external disturbance is established,and the mathematical model of continuous networked AC asynchronous motor with system parameter perturbation and external disturbance is established by considering system parameter perturbation.(2)In view of the influence of network induced delay and controller parameter perturbation on the controlled system,the non-fragile control of networked AC asynchronous motor is studied.The Lyapunov stability theory and the linear matrix inequality method are used to analyze the stability and the design of the non-fragile controller.The sufficient conditions for the asymptotic stability of the closed-loop control system and the expression of the controller gain parameters are obtained.The controller gain is obtained by solving the linear matrix inequality using the LMI(Linear Matrix Inequality)toolbox in MATLAB.The simulation results show that compared with the traditional controller,in the case of parameter perturbation of the controller,the non-fragile controller can make the controlled system asymptotically stable while satisfying the set performance index.(3)For the problem of system parameter perturbation and network induced delay in networked asynchronous motor control system,the robust stabilization problem of networked AC asynchronous motor control system is studied.Using the method of time-delay segmentation and constructing a new LKF(Lyapunov-Krasovskii Function,Lyapunov functional)based on the improved Wirtinger inequality,the stability criterion of dependent time-delay is derived.The state feedback controller is designed and the controller gain parameter is obtained by CCL(Cone Compensation Linear)algorithm.Simulate by using the LMI toolbox.The results show that the robust controller can make the controlled system asymptotically stable in the case of system parameter perturbation and time-varying time lag.Finally,the work of the full text is summarized,and the existing problems and subsequent research directions are briefly arranged.