Design Of Continuous Wave Mud Pulser Controller

In(logging while drilling)LWD,the mud pulse generator,as one of the core components of oil and gas drilling equipment,undertakes the important task of uploading the downhole logging data to the surface,so the stability of the pulser is very important,and the accuracy of the data transmitted by the pulser depends on the control precision of the pulse generator servo control system.During the drilling process,the pulser will be interfered by strong disturbance such as extreme temperature,hydraulic torque and mechanical vibration,so the control system needs to have strong anti-interference ability.This thesis takes the motor control system of the continuous wave mud pulser as the research object to analyze and design the control system,aiming to improve the environmental adaptability of the control system and simplify the use of installation and debugging personnel.The thesis in detail discusses the design of the motor controller of the pulser and the environmental influence in the operation of the pulser.The scheme design of the motor controller is discussed in detail in the thesis.The three closed-loop PID control schemes contain current loop,speed loop and position loop are selected as the control scheme of the pulser motor.The PID controller structure is selected according to the control performance indicators of each loop.Designs the controller parameters according to the actual control requirements.Subsequently,the parameters of the three-closed-loop PID controller were re-tuned by means of experience debugging.The time-varying parameter model of the motor is built with MATLAB/Simulink software to simulate the influence of high temperature on the motor,and then the control system under the above two controller parameter design methods is simulated and compared.Simulation results show that the pulser control system under the two controller parameter design methods has a certain control ability under high temperature.Based on the influence of ambient temperature on the control system,a position loop fuzzy controller is designed on the basis of the three closed-loop PID controller to realize the automatic adjustment of the parameters of the position loop PID controller.The fuzzy control is built by using MATLAB/Simulink software.The pulser control system using the fuzzy controller has the adaptability of high temperature environment through the simulation comparison with the three closed-loop PID control system.Then,according to the position feedback device of pulse generator motor-resolver,there is an installation error in the installation process.A method for measuring the electrical angle zero position of permanent magnet synchronous motor and a matching multi-pole rotary transformer are proposed.MATLAB/Simulink software is used to build a multi-pole resolver control model and simulation prior.Finally,the three-closed-loop PID control scheme of the pulser is verified according to the experimental platform.The experimental results show that the three-closed-loop PID control system has high servo precision and good dynamic performance,which can meet the requirements of engineering application.