R & D Of Pumping Unit Group Controlling System With Frequency Conversion Based On DC Power Supply Configuration

At present, frequency control devices use more and more widely in the oil fields at home or abroad, for its superior performance and energy-saving implementation of the dual output simultaneously. But at the same time it also brought a series of questions, such as many current harmonics in net side, power factor low and dealing with generating electricity unreasonably, and so on. In response to these questions in this paper, and in accordance with the feature of many pumping units concentrated in the same block, standing on the shoulders of predecessors, we research and develop a pumping unit group controlling system with frequency conversion based on DC power supply configuration, so that the above-mentioned problems been solved. Not only it can greatly increase production and energy saving, but also significantly reduce the cost to further improve system cost performance.This system uses common DC bus power supply technology, which links many inverter terminals. With the application of common DC bus power supply technology, the original AC-DC-AC inverter main circuit is separated into AC-DC and DC-AC two parts, and many terminals use the same AC-DC part to supply DC power. In this paper, we analyse the DC power supply configuration, and develop a DC relay control circuit and a special switching power supply with a new self-start circuit, then in hardware and software design the single-chip control system, isolated drive unit , detection unit, and so on .And this system links many pumping units through the common DC bus. It can take greatest advantages of the group, recycle the energy generated, reduce harmonics and the transformer capacity in net side, improve the power factor, and prevent bootlegging electricity. Cooperating with the Zhongyuan Oil Field, we conducted a field test. In the test, the system improved the pumping performance, saved energy, increased the production of crude oil, and performed all the advantages above. And all of these proved the feasibility and reliability of the system.