Energy-saving Technology Of Beam Pumping Unit Based On Variable Speed Drive And Hybrid Power

In order to deal with the increasingly severe energy shortage problems,this paper studies the energy-saving system of beam pumping units from the perspective of energy consumption of oilfield pumping units.The current mainstream oilfield energy-saving technologies include hybrid and variable speed drives.Among them,the hydraulic auxiliary power is more typical in the hybrid power technology.However,the traditional hydraulic auxiliary power lacks effective countermeasures against the shock load and the huge fluctuation caused by the load switching in the oil production system.The single variable speed drive still has large torque fluctuation and waste of part of the gravitational potential energy.In order to realize technology complementation and fully absorb its advantages,this paper proposes a model for coupled energy-saving systems based on variable speed drives and hybrids,and discusses the correctness and feasibility of the model from the perspective of simulation and physical experiments.The research contents of this paper are as follows:In this paper,the kinematics of the four-bar linkage mechanism of the beam pumping unit is firstly analyzed,and the motion law of the suspension point is obtained;the dynamic model of the suspension point is improved by using the three-dimensional wave equation;the variable-speed drive model of the conventional pumping unit is proposed and established.The main process is: establish a variable speed optimization objective function aiming at reducing the comprehensive power saving rate of the motor,perform Fourier expansion and optimization on the input power curve,and on this basis,establish a predictive calculation model for the nonlinear coupling behavior of the pumping unit system To optimize the variable speed drive model;in order to verify the model effect,a simulation program was established in Visual Basic 6.0,and the CYJ10-3-37 HB pumping unit was selected for constant speed and variable speed simulation.By analyzing the curves of the two working conditions simulated by the simulation,this paper obtains that the motor efficiency of the variable speed drive and the traditional drive mode has been greatly improved,but there are still torque fluctuations,the peak load is still relatively high,and some problems such as negative torque occur.The proposal and analysis of the variable speed drive model lays the theoretical and model basis for the establishment of the coupled energy-saving system based on variable speed drive and hybrid power..Subsequently,this paper describes the energy saving principle of coupled systems based on variable speed drives and hybrids.On this basis,the core element model of the coupled system is established,including pump/motor,accumulator,torque coupler,etc.,and the motor efficiency equation of the coupled system is solved.Based on this equation,the key parameters affecting the coupled energy-saving system are discovered.Because the change law of some component parameters is opposite to the optimization goal,in order to achieve the goal of global optimization,the initial value of the variable and the optimization range are formulated with the minimum energy consumption of the motor as the goal,and the simulated annealing algorithm is used to match the parameters.Based on the speed and torque control requirements of the variable speed drive motor model,this paper builds a motor sub-model considering the relationship between load rate and efficiency in AMESim,and builds other sub-modules in SIMULINK to form a co-simulation system.Through the analysis of the simulation results,the coupled energy-saving system based on variable speed drive and hybrid power system is more stable in torque than the traditional drive mode,the load rate of the motor is improved,and the working efficiency of the motor is effectively improved.With the improvement of the full pump rate,the overall suction efficiency has also been greatly improved.Due to the cold start effect of the hybrid system and the stability of the motor output power,the coupled energy-saving system can significantly reduce the installed power,from37.5kW in the traditional drive mode to 13.5kW.The correctness of the model is verified from the simulation point of view.Considering the low efficiency of torque matching under variable speed conditions in the actual production environment,this paper proposes a torque matching strategy for coupled systems based on fuzzy PI control,and designs a fuzzy PI controller.Then build the physical test bench,compile the physical experimental control program based on Lab VIEW,and complete the coupling energy-saving system experiment.By analyzing the experimental data curve,the role of the coupled energy-saving system in "cutting peaks and filling valleys" was found,and by comparing the traditional drive mode,variable-speed drive mode and the coupled energy-saving system driving the real working efficiency and installed power of the motor in three modes,further The energysaving effect of the coupled energy-saving system model is verified.And the feasibility of this technical solution is verified from the perspective of cost.Through the research in this paper,the energy-saving effect of the coupled energysaving system based on variable speed drive and hybrid power system is improved to different extents compared with the traditional mode and the variable speed drive mode.Due to the cold start of the hybrid system,the installed power has been greatly reduced from 37 kW to 13.5kW.With the increase of the motor load rate,the motor efficiency has increased from 77% to 92%,and the draw efficiency of the entire system has been improved.The research results of this paper are of great significance to the development of the oil-pumping unit energy-saving system,and provide a theoretical basis and scientific basis for the research of the new oil-pumping unit energy-saving system.