Study On Adaptive Control Method Of Soft Torque For Rig Rotation System

With the development of drilling demand to deep strata and deep sea strata,the difficulty of mining is increasing,and the demand for drilling levels is also increasing.At present,the top drive system has been widely used in drilling operations due to its advantages of high efficiency,stability,and safety.However,under the drive of a top drive motor,the underground drill bit will inevitably produce stick-slip vibration,and the stick-slip vibration will not only extend Well time,shortening the life of drilling tools,and may also cause major safety incidents.Therefore,it is very important to design a set of “soft torque control system” in order to prevent stick-slip vibration phenomenon in drilling rig rotating system,in order to ensure drilling efficiency,protect drilling equipment and maintain the stability of the system.This paper takes the rig rotation system as the research object.Firstly,the working principle and flow of the soft torque control system are studied.The overall scheme of the soft torque control system is proposed and the control block diagram of the soft torque system is given.Secondly,the mathematical model of the top drive motor in the system is established,and the currently used direct torque control system is studied.Aiming at the problem of direct torque control system,the space vector pulse width modulation(SVPWM)technology is proposed and simulated.In addition,through the analysis of the drill string system,a drill string system model was established,which was combined with the top drive motor system,and the rotary system model of the drilling rig was set up.The situation of stick-slip vibration under the direct torque control system was simulated and analyzed.Finally,according to the characteristics of drilling rig rotation system,PID controller,sliding diaphragm variable structure controller and first-order integral synovial membrane adaptive controller are designed respectively.Under the condition of slow and time-varying system parameters,the control effects of different controllers are compared and verified.The effectiveness of the soft torque control system.