Research On Sensorless Control Systerm Of Arc Permanent Magnet Motor In Low-Speed

Arc permanent magnet motor is widely used in driving system of large astronomical telescope because of its simple structure,easy installation and direct drive.However,due to the harsh working environment of large astronomical telescopes,the traditional mechanical position sensors are greatly affected by environmental factors and cannot be used normally in extreme weather.Therefore,it is of great practical significance to use sensorless control technology to replace mechanical position sensors in the driving system of large astronomical telescopes.Firstly,the research status of arc permanent magnet motor control system is described,and five sensorless control methods of permanent magnet synchronous motor at low speed are comprehensively analyzed.Secondly,an improved pulse high frequency signal injection method is proposed.By determining the amplitude and frequency of the injected high frequency voltage signal,the high frequency response current is obtained by injecting the pulse high frequency voltage signal into the static coordinate system.The high frequency response current is extracted by the adaptive filter designed in this paper,and finally the position information is obtained by the rotor position observer.This method effectively reduces the position estimation error,improves the position tracking accuracy of the control system,and achieves the purpose of improving the low-speed tracking characteristics of large astronomical telescopes.In order to improve the anti-interference performance of the system,a torque observer considering the load torque fluctuation is proposed to reduce the speed fluctuation of the arc permanent magnet motor.Meanwhile,an adaptive controller based on the characteristic model of arc permanent magnet motor is designed.The controller can effectively resist the external disturbance,improve the robustness of the system,and finally realize the dynamic accurate control of the arc permanent magnet motor at low speed.Finally,the adaptive control is combined with the improve pulse high frequency voltage signal injection method,through the simulation analysis of rotor position,rotational speed and torque in the control system of arc permanent magnet motor.The results show that the improved low-speed sensorless control system of arc permanent magnet motor has better position tracking performance,stronger anti-interference ability,and the overall control performance of the system is higher.