Simulation Research On The Loading Device Of Pumping Unit And Its Control System

Beam-Pumping unit is the most widely applied equipment in the oil-field. It is also the primary device of energy consumption. Its own structure comes into being its particular load characteristic, possessing impulsive alternative load. In order to recognize the actual running state of pumping unit, and to design an energy-saving device with control system, it is necessary to study the load characteristic of pumping unit whose working load changes greatly, so as to provide theoretical foundations for the energy-saving function of Pumping unit.This dissertation mainly studies of the load simulator device of pumping unit in deeply theory and fulfills the simulator construction which combines magnetic powder brake with flywheel. In terms of field test data, it can reproduce the load message, and control the magnetic powder brake with the advanced control method, thereby meet the control demand of the load simulator device. The main research contents are as follows:Firstly, it analyzes the present research statue of the load simulation system, and designs a load simulator for pumping unit according to its load characteristic.Then, it analyzes the sucker rod load of the pumping unit. After establishing a mathematical model of the sucker rod load according to the rod motion principle, and, investigating the rod load transmission and transformation process, it obtained the motor output torque. The calculated result is compared with the measured data which play an important role for the load simulation device. Moreover it summarizes the existed load simulation techniques. On this basis, it constructs a novel load simulator for the pumping unit and describes its operation principle and its components.In addition, it implements the curve fitting of the measured data by "cftool" embedded in the software of Matlab. By this mean, it analyzes the mechanical characteristic of Three-phase Inductive motor and sets up the mathematical model of the load simulator of pumping unit for the sake of simulating its mechanical components to verify the correctness of each mechanism parameter.Finally, the dissertation researches the control strategy of positive and negative load's simulation of the Pumping Unit, designs a PID controller and makes use of Simulink tool involved in Matlab to simulate and attain visual simulation results so as to adjust the parameters and to achieve a favorable control effect.As a conclusion, it is important to design the load simulator due to its realistic meanings covering the provision of data support on the researches of energy-saving control system of Pumping Unit, the realization of saving energy and lowering energy dissipation of Beam Pumping Unit along with the solution to the problem of the too much low efficiency when the rod pumping unit runs. Meanwhile, the study of this dissertation is a multi-disciplinary intersectant project, which involves mechanics, electronics, automatic control technology and computer technology and realizes the high-level combination of mechanics and electronics.