Research On UDE Control Based On Load Torque Compensation Of PMSM

The mud pulse measurement while drilling technology,as the main hotspot of wireless transmission of underground information in the current petroleum drilling field,has increasingly high requirements for the speed and reliability of information transmission.The continuous wave mud pulse transmission method is the forefront development direction of mud pulse measurement while drilling technology due to its transmission speed being more than 10 times that of traditional positive pulse method and its economic reliability.The dynamic performance of Permanent Magnet Synchronous Motor(PMSM),which drives the core component of the rotary valve,has a significant impact on the quality of underground information transmission.The rotary valve movement is affected by the time-varying hydraulic torque in the underground,and the motor parameters change with changes in factors such as well depth and temperature,greatly affecting the dynamic performance of the control system of the rotary valve drive motor,Therefore,studying the corresponding control strategies is of great significance for the development of continuous wave mud pulsers.In engineering,PMSM traditionally adopts PI control strategy,but its control performance weakens and its robustness is poor under the influence of motor parameter changes and time-varying external disturbances.Therefore,this article proposes to apply a control strategy based on Uncertain and Disturbance Estimating(UDE)to the control of pulser motors,treating uncertain disturbances such as internal parameter changes and external torque disturbances as lumped disturbances,and observing and compensating for the disturbances,thereby improving the robustness of the control system.In the UDE control strategy,the Filter design is a low-pass form,which shows insufficient response to the high-frequency changes in the external disturbance of time-varying torque,thus affecting the rapidity of control.To solve this problem,a UDE control strategy based on load torque compensation is proposed.By designing the feedforward compensation of the load torque observer for time-varying torque,the pressure of high filter bandwidth requirements in the UDE controller is relieved,Furthermore,the tracking error of high-frequency components in time-varying load torque is reduced,forming a composite control combining feedforward control and feedback control to improve motor control performance.In order to verify the feasibility and effectiveness of the proposed control strategy,simulation modeling and validation were conducted on PMSM’s PI control system,traditional UDE control system,and UDE control system based on load torque compensation in the Matlab/Simulink software environment.Three control strategies were experimentally validated on the Links-RT semi physical simulation platform,and the simulation and experimental results were compared and analyzed.The results indicate that the UDE control strategy based on load torque compensation for PMSM designed in this paper has better dynamic performance and robustness compared to the other two control strategies,thus providing a corresponding theoretical and technical basis for the implementation of the control system of continuous wave pulser driven motors.