Study And Design Of Electro-hydraulic Servo Loading System For The Pumping Unit

As one of the three major energy that support today’s society development, oil is known as the blood of modern economic development. China is an oil consumption big country, also a big producer. Pumping unit is widely used in most of the ground well in our contry for oil producing, its work efficiency is low and power consumption as high as 30~40 billion kWh. So its performance is urgent to be improved. Pumping unit is one kind of heavy equipments and works in bad conditions. Therefore it has great significance for study and improve the working performance, if we can simulate pumping unit’s working conditions in the lab. Combined with the mechanical, hydraulic, computer and electronic technology, this paper designs one type of electrohydraulic servo loading system for the pumping unit.This paper introduces the development course of the pumping unit loading system and the current research status of electro-hydraulic servo system. According to the working conditions and technical requirements of the pumping unit, a double closedloop control electro-hydraulic servo system is designed using the electro-hydraulic servo technology. Analysis the function of double servo valves hydraulic loading system, calculate the parameter and select of the main components for seting up the hydraulic system. The control system of the servo loading system is designed, using PLC as the lower machine and PC as upper machine. The comunications between the PLC and PC is realized by OPC technology. Introducing the PID control algorithm and the fuzzy self-tuning PID control algorithm, the fuzzy PID control algorithm, the procedure of the control system and the human-computer interaction interface is designed by Lab VIEW software. In order to analysis the effect of the interference caused by the extraneous force, the models of the electro-hydraulic servo loading system is set up, and then the advantages of the double servo valves control system is analyzed. The software of AMESim is used to test the validity and rationality of the hydraulic system and control algorithm. The key parts of the design are researched and tested in the simulation testing platform. The test results shows that the design of the system conforms to the anticipated target, that is to say the system can satisfy the design requirement.