Design Of Driving And Controlling Module For Reciprocating Mud Pulser

Oil is an indispensable strategic resource that is linked to the growth of the national economy.Logging while drilling(LWD)technology is critical in the petroleum prospecting process.As a crucial instrument in LWD,the mud pulser performs an essential task: it transmits well logging data to the surface system.The reciprocating mud pulsator encodes logging data as a mushroom head movement track,causing drilling fluid to generate pressure signals conveying information to complete data transmission.The design of the circuit for driving and controlling the reciprocating mud pulser,the choice of a controlling strategy,and the design of the controlling structure and programs are the three primary topics covered in this thesis.Based on Linear Active Disturbance Rejection Control(LADRC)and PID classical control strategies,a doul-closed-loop control structure is designed in the thesis.The PI current loop serves as an internal loop for accurate and rapid torque control,while the LADRC position loop serves as an external loop,estimating and compensating for pulser interference.The thesis designs MATLAB/SIMULINK simulation experiments and actual operational experiments of the pulser for the dual closed-loop control structure of LADRC position loop and PI current loop.The results show that the control structure has good control performance and resistance to interference,which is suited for controlling the reciprocating mud pulser.In driving and controlling circuits designing,the thesis creates an embedded minimum system based on DSP for driving and controlling of pulser,system communication,and data storage.The pulser driving circuit uses six IGBTs as a power device,creates a three-phase inverter bridge and completes the module design of current collection,voltage collection,and overcurrent protection.System communication modules with computer and main-controlling instrument are achieved via RS-485.Storage module is made up of a 512 MB Nor Flash array and a 64 KB EEPROM.The experiments are conducted and the results demonstrate that the circuits’ functions are normal and meet a number of performance metrics.In driving and controlling software module designing,the deprivation micro-control real-time operating system is introduced.According to different functions and software needs,eight tasks are designed,which realize upper level functional requirements.The operational system provides task management and scheduling services,synchronization and sharing services,which improving the reliability of software program and ensuring the stable operation of the pulser.