Networked Control Of Permanent Magnet Synchronous Motor Based On H_? Theory

Permanent magnet synchronous motor(PMSM)has the characteristics of small size,large starting torque and high magnetic energy density,which has become the key research object in the field of servo control and has been widely used in the occasions with high requirements on motor performance.With the improvement of industrial production capacity and the continuous expansion of production scale,the industrial site becomes more and more complex,and a large number of motors appear in a wide area.If the traditional point-to-point control method is adopted,its construction difficulty and operation and maintenance cost are extremely expensive.In this dissertation,networked control system(NCS)emerged.The introduction of network leads to data packet loss and information congestion in the transmission of information in network channels,which will reduce the servo control performance of the system and even make the system unable to work stably.Using the coordinate transformation method,the three-phase dynamic model of PMSM and its two-phase decoupling motor model in the rotating coordinate system were established,and a PMSM servo simulation platform with space vector pulse modulation(SVPWM)technology as the core was built in Matlab/Simulink software.For a single permanent magnet synchronous motor,the H_?method is used to design a robust speed servo controller.The control network is introduced into the permanent magnet synchronous motor servo system,and the mathematical model of networked control of permanent magnet synchronous motor servo system is established based on reasonable assumptions and the forming mechanism of time delay.Using lyapunov-krasovskii functional method and H_?control theory,the time delay stability of servo system is analyzed.The free weight matrix method and newton-leibniz formula are used to replace the integral terms,and the sufficient conditions for the existence of the controller are given in the form of linear matrix inequality(LMI).In the design of H_?controller,model uncertainty factors are fully taken into account.In the process of solving the controller,parameter adjustment algorithm and substitution method are used to linearized the nonlinear matrix inequality,and LMI toolbox in Matlab is used to solve the problem.According to the control effect of the two methods,simulation experiments are carried out.The results show that compared with the free weight matrix method,the networked PMSM servo controller designed by using newton-leibniz formula substitution method combined with H_?control theory has better dynamic performance when dealing with network delay,data packet loss and motor load torque disturbance.