Frequency converting and energy saving device of oil pumping machine

Abstract

The invention relates to a frequency converting and energy saving device of an oil pumping machine in the technical field of electronic control. The device comprises a breaker, a frequency converter, a current transformer, an input reactor, a first contactor, a second contactor, a third contactor and a thermal relay, wherein an external power supply is connected with the breaker, after the external power supply is controlled by the breaker, the external power supply is divided into two paths of circuits through the current transformer, and one path of the circuit is a frequency conversion loop, while the other path of the circuit is a power frequency loop; the frequency conversion loop firstly passes through the input reactor and then enters the frequency converter through the third contactor, and after the frequency conversion loop is subjected to frequency conversion through the frequency converter, the frequency conversion loop enters the first contactor; the power frequency loop comprises the second contactor and the thermal relay which are connected in series; and the whole power frequency loop and the frequency conversion loop are connected in parallel. The frequency converter is added in a control cabinet of the oil pumping machine so as to improve the output and the pump efficiency of an oil well, compensate the power factor, avoid impacts to power grid equipment when a motor is started and realize arbitrary jig frequency regulation and segmental rotating speed control.

Description

technical field [0001] The invention relates to a device in the technical field of electronic control, in particular to a frequency conversion energy-saving device for a pumping unit. Background technique [0002] At present, the cost per ton of oil in China is several times that of foreign countries. It is an inevitable trend of China's petroleum industry to save energy and increase efficiency as much as possible, and to be in line with international standards. In the cost per ton of oil, electricity expenses account for about one-third of the production cost, and with the further exploitation of the oil field, it is very important to save energy, increase efficiency, increase production, and reduce consumption on the basis of stable production. The pumping unit is the most basic equipment in the oil field, so it is more meaningful to save energy and reduce consumption of the pumping unit. According to preliminary estimates, in Daqing Oilfield alone, there are about 7,000...

AI Technical Summary

Problems solved by technology

[0004] When the existing pumping unit is in use, there is still the problem that the motor will cause a great impact on the power grid and equipment at the moment of starting

When the motor is started at power frequency, the starting current is equivalent to 3 to 7 times the rated current. Therefore, when the motor is started with load, it will cause a great impact on the equipment and the power supply grid, resulting in excessive requirements on the grid capacity.

Moreover, a large current and vibration are generated at the moment of starting, which is extremely unfavorable to the equipment, and in serious cases, the pumping unit may break and other phenomena may occur.

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