Research On The Motor Control System In Continuous Wave Signal Generator Based On Shear Valve

The MWD is a technique for transferring measurement data from underground measuring instruments to the ground during the oil drilling process,which is important for the safety and efficiency of drilling.As the logging dat a is required to be increased,the Logging data transmission speed becomes an important problem that MWD needs to solve.The continuous wave mud pulser based on shear valve is a kind of logging data transmission method with better development prospect,its motor control system is one of the key links.The research content of this paper is the permanent magnet synchronous motor control system of continuous wave signal generator based on shear valve.In this paper,the principle of data transmission of the continuous wave signal generator is firstly introduced,and several modulation methods of continuous wave signal generator are analyzed.A kind of phase modulation for shear valve type continuous wave signal generator is designed the way.Then the control scheme of permanent magnet synchronous motor is designed.The permanent magnet synchronous motor adopts the control scheme of three closed-loop structures with motor position,velocity and current as the feedback.Each closed loop adopts PID controller.Through the frequency domain modeling and analysis of the motor control system,the design formulas of each closed-loop controller are deduced,and the motor control system is simulated by MATLAB / Simulink software,the feasibility of the control scheme and the parameter design of the controller is preliminarily verified.According to the control scheme of the motor control system,the software and hardware of the control system are designed.The hardware to TMS320F28335 as the main control chip,including the power drive circuit,detection circuit,protection circuit,auxiliary power supply circuit and so on.T he software part introduces the flow of main program and interrupting the subroutine,and key software part of the motor initial positioning,speed measurement,current speed processing and SVPWM generation are described in detail.Finally,the experimental platform is designed to simulate the data transmission process of continuous wave signal generator.The experimental platform consists of pump,shear valve,permanent magnet synchronous motor and its control system,sputtering thin film pressure sensor and so on,In the experimental platform for data transmission experiments.The experimental results show that the motor control system of the shear valve continuous wave signal generator can drive the shear valve to obtain the demodulated sine pressure wave signal in the experimental environment.