The Research Of Variable Frequency Hydraulic Rotating Circuit In Top Drive Drilling System

as one important technology of petroleum equipments in the21st century, compared to the traditional rotary drilling,Top drive drilling system has a lot of advantages and has become an irreversible trend. In the international market,an drilling machinery with a top drive device has made significant improvements in use range, work performance, drive form and transmission, embodies the great competitive advantage, has now developed into a comprehensive mechanical and electrical integration of liquid oil drilling equipment.There are the hydraulic top drive and electrical drive way,at present, the hydraulic drill rig is developing in the direction of full hydraulic pressure drive. full hydraulic pressure drive type is adopted in the majority of the world’s most famous drilling companies because of the higher power efficiency.With the rapid development of modern society, energy conservation has reached a consensus in each industry, an variable pump is used in controlling an motor in the traditional top drive device hydraulic slewing system, in this paper frequency conversion technology applied in the top drive device hydraulic slewing system realized the purpose of saving energy, which is a beneficial attempt.The pump controlled motor rotation circuit in full hydraulic top drive device is an important circuit in which top drive system drives rotation of drill string, is an important part of the main action actuator in the process of drilling, the rotating circuit of fully hydraulic top drive device is regarded as the object, and ac variable frequency speed regulation technology was used to study on the object of energy saving in top drive device.Analyze the working principle of a top drive variable frequency hydraulic slewing system;according to the requirements of the work, the parameters of the system are calculated and the selection of the various components are involved. Establish open-loop frequency conversion and closed loop PID control frequency conversion and variable pump control motor simulation model of top drive device in AMESim; analyze the influence of parameters of variable frequency motor speed and torque output in open-loop variable frequency hydraulic slewing system; Under three different simulation models, analyze motor output torques and rotational speeds in different signals;And compare energy output of the variable frequency system with that of variable displacement pump system.Check the validity of the frequency conversion device simulation model which is setted up.Point out that the open loop and closed loop variable frequency hydraulic slewing system has realized the system power match,and meet the actual working characteristics of hydraulic slewing system:drill string of the top drive rotary speed decreases and the output torque increases when meeting a hard rock,;Speed increases and the output torque decreased when faced a soft rock;and compared to the traditional variable pump control motor top drive hydraulic circuit system, saving energy is realized.