Research On Dynamics And Control Optimization Of Intelligent Beam Pumping System

With the development process of oil fields,the difficulty of crude oil extraction increases.The conventional beam machine has problems such as single operating state and cumbersome balance adjustment,and the new pumping system should have the advantages of controllable stroke,balanced closed-loop adjustment,and intelligence.The design scheme of asynchronous motor pumping machine in this paper is mainly researched as follows:An intelligent beam pumping machine was designed.Based on the structure of composite balanced beam pumping machine,this machine adopts frequency converter to control the instantaneous frequency of three-phase asynchronous motor,realizes the automatic adjustment of pumping machine stroke,and improves the power performance of the system by optimizing the real-time frequency;The pneumatic balancing device is used to realize the automatic adjustment of the balance state.The machine can have the advantages of simple structure,reliable operation,superior power performance,etc.,and realize the intelligent adjustment of stroke and balance state.Considering the real-time change of frequency,a mechanical characteristics simulation model of frequency conversion control asynchronous motor is established.On the basis of establishing the simulation model of single-degree-of-freedom rigid member system of ground device and the longitudinal vibration simulation model of sucker rod column based on wave equation,the electromechanical coupling dynamic simulation model of intelligent pumping system is established.The simulation results show that the intelligent pumping system has superior power performance and significant energy-saving effect.The real-time frequency function of voltage is simplified to Fourier series,the coefficient of Fourier series is taken as the optimization design variable,and the constraints such as stroke number,upper and lower stroke time ratio,frequency variation range and oil well production are comprehensively considered,and the objective function of the system optimization design is established with the average motor output power and the rms of the crank net torque weighted minimum.The optimization results show that optimizing the realtime frequency function can significantly improve the dynamic performance and energysaving effect of the intelligent pumping system.Based on the spatial vector transformation and SVPWM algorithm of rotor flux linkage directional control,the decoupling control of excitation current and torque current is realized,and the classic PI regulator of motor speed loop and current loop is designed,and the realtime frequency online closed-loop control system of power supply is established.Based on the balance range constraint,a pneumatic balance closed-loop system is established.The simulation results show that the designed closed-loop control system has high control accuracy and realizes the optimal operation of the pumping system.