Research On Energy Saving Control Of Beam Pumping Units

Beam pumping unit is one of the most widely used oil field production equipments. Its mechanical structure is simple, which is easy to be maintained. And it can adapt to bad weather outdoors, which insures long time running. But its energy consumption is large, and working efficiency is low. Therefore, the improvement of energy saving system and automation degree of the system are the problem that urgent need to be solved in the oil field.For a long time, many experts and technicians have been committed to energy saving of the beam pumping unit, and have obtained some achievements. At present, there are two directions of energy saving in oil fields. One is to improve the mechanical structure of beam pumping unit, the other is to change the performance characteristics of the motor. In this thesis, the research object is the conventional beam pumping units, the mechanical structure and working principle of the beam pumping unit have been learned and reserarched. At the same time the motion law of bar linkage of the beam pumping unit has been analyzed. Firstly, we improve the mechanical structure of the beam pumping unit by using the mechanical balance to realize the energy saving, furthermore, we calculate the balance radius, balance quality and it’s regulating variable in the movement process when use the crank balanced, beam balance and composite balance mode. Then, the way of changing the work characteristics of the motor has been used to realize the energy saving, and a variable frequency speed control system has been designed using the Rockwell Automation products. The output power and speed of the motor is the feedback, and constitute the closed-loop control system. Finally, the PID controller is applied to the system, and in the power loop, according to the different situation, PID controller and PD controller have been used respectively, to ensure the system in good operating and reach good energy saving effect.At last, the mathematical model of the beam pumping unit of energy control system has been established, and the parameters of the PID controller have been calculated. And the simulation results prove the effectiveness of the mathematical model and the feasible of the PID control algorithm. Through the analysis, it can conclude that PID controller can make the system having a good ability to tracking the set value, realize the closed-loop control of the energy saving control system of beam pumping unit, and achieves a good effect of control.