Research On Oil-pumping Unit Motor’s Energy Saving Technology By Voltage Regulation With Y-Δ Change-over And Thyristor

In the current oil fields, beam pumping unit which is widely used in oil extraction, is the major energy-consuming equipment. As the special conditions and complex environments when pumping actually, the load rate of three-phase asynchronous motor, one of the main pumping unit drives, is low. And the rapid variety of the load rate will result in uneconomically using energy and excessive loss of power.In this paper, according to the analysis of the operation conditions of the pumping unit, the comparison of various methods of pumping energy saving, and the particular practical application, that the energy-saving effect of Y-△ change-over controller is better than the thyristor voltage regulating style when the load rate of oil-pumping unit is low, but the thyristor voltage regulating style is better than the energy-saving effect of Y-△ change-over controller when the load rate of oil-pumping unit is high, an new energy saving controller of combining the advantages of both controllers is designed. On this basis, the paper completed the device’s main circuit and control circuit design, this design uses the electrical energy measurement IC-ATT7022A to detect pumping unit motor voltage, current, power factor, phase angle and other power parameters, and takes AVR-Atmega128 as CPU, this way reduces the amount of processor operation and the complexity of software design, and improves the system stability and reliability. According to the detected power parameter, controller will switch between Y-△ voltage-regulator and thyristor voltage-regulator, control voltage regulating and Y-△ conversion. Controller has the function of saving data such as operating parameters and operating status of the pumping unit. At the same time, it designs a communication interface and human-machine interface to be easy to use controller. The controller software design uses modular design concept, it has the advantages of the powerful overall function, independently process at the same time, and that failure of any one module does not affect the normal operation of other parts of the system. The way increases the scalability of software programs.