Research On Position Sensorless Adaptive Control Technology Of Permanent Magnet Synchronous Motor

With the increasing progress of industrial technology,permanent magnet synchronous motors are playing an increasingly important role in the field of industrial control,especially for the manufacturing cost and high-speed and high-precision control of high-end CNC machine tools in the field of feed systems.Based on the application of permanent magnet synchronous motor sensorless control technology in the CNC machine tool feed system,the following research is carried out:Aiming at the position sensorless control technology of permanent magnet synchronous motors,combined with the physical model of surface-mounted permanent magnet synchronous motors,mathematical models of permanent magnet synchronous motors in different coordinate systems are established.Analyze the configuration method of current loop,speed loop and position loop control parameters in the "three closed loop" position servo control technology.For the field-oriented control of permanent magnet synchronous motors,the space vector pulse width modulation technology is studied.For the permanent magnet synchronous motor sensorless control technology,the position tracking accuracy in the position servo process is relatively large and it is difficult to meet the control accuracy requirements of the actual CNC machine tool feed system.A variable parameter adaptive law MRAS speed observer model is proposed,which dynamically changes the control parameters in the adaptive law through the change of the current state quantity in the motor control process,thereby reducing the position tracking based on the MRAS speed observer in the sensorless control process error.Aiming at the problem of large speed fluctuations caused by the change of reference position command in the process of permanent magnet synchronous motor sensorless position servo control,based on the idea of variable control parameters,an improved variable exponential reaching law sliding mode speed controller is proposed,which can feedback according to the speed The deviation value dynamically adjusts the control parameters in the sliding mode exponential approaching law.The improved sliding mode speed controller is used to replace the speed PI regulator in the "three closed loop" control to reduce the speed fluctuation in the sensorless position servo control process.Based on the above research,a simulation model of sensorless control with variable control parameters is built based on the MATLAB/Simulink simulation platform.The simulation results show that the sensorless control with variable control parameters can effectively reduce the position tracking error compared with the sensorless control with fixed parameters.A related hardware test platform was built,and the experimental results were compared with the actual machine tool feed axis position and speed response characteristics under servo control.The results proved the feasibility of the variable control parameter sensorless control technology.