Study On Permanent Magnet Synchronous Motor Control System Based On Sliding Mode Observer

Permanent magnet synchronous motor plays an important role in modern industrial production and people's daily life due to its simple body structure,relatively small volume to body weight ratio,high energy density and high reliability.However,in the motor motion control system,it is necessary to know the rotor position information of the motor when using the vector control algorithm.A mechanical sensor such as a resolver can be placed on the rotating shaft,and then the signal can be obtained by decoding the chip.However,this method increases the cost of the entire control system and reduces the stability and reliability of the control system.These factors limit the permanent magnet synchronous motor to be widely used in various environmental environments.Based on the above reasons,domestic and foreign scholars have studied the sensorless control technology of permanent magnet synchronous motor as a hot topic to overcome various problems brought by mechanical sensors.Firstly,the paper uses the coordinate transformation method to decouple the complex relationship of the three-phase model of the motor into the mathematical model under the dq coordinate system.According to the simulation experiment and the motor structure of the experimental platform,the control method with id=0 is finally determined.The mathematical model of the permanent magnet synchronous motor in two-phase stationary coordinate system is rewritten as a mathematical equation containing back electromotive force.The current sliding mode observer is designed according to the mathematical equations in this coordinate system,and the back electromotive force is estimated to extract the rotor position information.The subject uses a saturation function instead of the traditional switching function,and chattering is effectively weakened.In this paper,the simulation model of PMSM vector control system based on sliding mode observer is established in MATLAB/Simulink simulation environment to verify the effectiveness of this algorithm in motor motion control system.In order to prove that the sliding mode observer can be applied to the PMSM control system,this paper designs the hardware circuit of TMS320F28335 as the main control chip and the matching software program.The experimental platform is built for the control strategy of the synovial observer,and the experimental data is collected and analyzed.The experimental results show that the sliding mode observer can accurately obtain the rotor position and realize the good operation of the sensorless control system of the PMSM.