CN216016760U - Frequency conversion control system of oil pumping unit - Google Patents

Abstract

The utility model relates to a frequency conversion control system of a pumping unit.A main transformer reduces three-phase 1140V alternating current output by a power supply to 660V, and then supplies power to an oil pumping motor through a frequency converter; the auxiliary transformer reduces the voltage to 380V again and then supplies power to the cooling fan; according to the utility model, through frequency conversion transformation, the performance of the existing driving system is improved, the frequency converter is used for controlling the oil pumping motor, the requirement of the characteristics of a cow and a horse of the oil pumping machine is met, the oil pumping motor keeps higher efficiency under the condition of light load, the loss is low, the efficiency and the power factor are high, the motor does not need to be replaced, and the transformation cost is greatly reduced; and the situation of insufficient cooling during low-frequency operation is avoided by adopting an independent cooling fan; the working voltage of the frequency converter and the oil pumping motor is reduced to 660V through the main transformer, so that the optimal cost of the frequency converter and the oil pumping motor is realized, and the on-site equipment assets are not wasted.

Description

Frequency conversion control system of oil pumping unit

Technical Field

The utility model relates to the technical field of control of pumping units, in particular to a variable frequency control system of a pumping unit.

Background

At present, the total number of oil production wells in oil fields in China is 74801, wherein the number of pumping wells accounts for 81.8 percent of the total number of wells (50.5 percent of old areas and 31.3 percent of the periphery); the rod pump well and the electric pump well account for 10% and 1.5%, respectively. By carrying out on-site monitoring on the 9178 motor-pumped production well, 934 existing motors are used as obsolete equipment in the on-site inspection process, account for 10.18 percent of the total monitoring amount, and indicate that a certain amount of obsolete motors are still used at present. In order to improve the operation efficiency of equipment, reduce the production energy consumption of an oil field and realize quality and efficiency improvement, high-energy-consumption lag electromechanical equipment must be eliminated and updated.

The energy-saving type oil pumping machine is designed by changing the structure of the oil pumping machine at present through energy-saving transformation of the oil pumping machine. For example, various energy-saving motors are selected, including high slip, ultrahigh slip, double power, low speed, self-variable power, rare earth permanent magnet motors and the like.

The switched reluctance motor has unique advantages, such as wide speed regulation range, excellent speed regulation performance, low loss, high efficiency and power factor, good starting characteristic, and high-efficiency operation under the condition of low speed and light load, and has the advantages of a direct current speed regulation system and an alternating current speed regulation system. Therefore, when the pumping unit is subjected to energy-saving transformation at present, the motor is generally transformed into the switched reluctance motor. But replacing the motor adds significantly to the cost of retrofitting.

SUMMERY OF THE UTILITY MODEL

Based on the expression, the utility model provides the variable frequency control system of the oil pumping unit, which improves the performance of the existing driving system through variable frequency transformation modification, meets the requirements of the characteristics of the cow and the horse of the oil pumping unit, does not need to replace a motor, and greatly reduces the modification cost.

The technical scheme for solving the technical problems is as follows: a frequency conversion control system of an oil pumping unit comprises a three-phase 1140V power supply, a main distribution voltage, an auxiliary distribution voltage, a main transformer, an auxiliary transformer, a frequency converter, an oil pumping motor and a cooling fan; the primary end of the main transformer is connected with the three-phase 1140V power supply, and the secondary end of the main transformer is connected with the main distribution voltage; the primary end of the auxiliary transformer is connected with the main distribution voltage, and the secondary end of the auxiliary transformer is connected with the auxiliary distribution voltage; the oil pumping motor is connected with the main distribution voltage through the frequency converter; the cooling fan is connected with the auxiliary distribution voltage and used for cooling the oil pumping motor.

On the basis of the technical scheme, the utility model can be further improved as follows.

Further, a thermal relay is connected in series between the auxiliary distribution voltage and the cooling fan.

Furthermore, the variable frequency control system of the oil pumping unit also comprises a PLC (programmable logic controller), wherein the PLC is connected with the auxiliary distribution voltage; and the PLC is connected with the oil pumping motor and the frequency converter, and the frequency converter is controlled by the working state of the oil pumping motor.

Furthermore, the pumping unit frequency conversion control system further comprises an alarm device, and the alarm device is connected with the PLC.

Furthermore, the variable frequency control system of the oil pumping unit further comprises a communication device, and the communication device is connected with the PLC and used for exchanging real-time data with the control center.

Furthermore, the oil pumping motor is a permanent magnet motor.

Further, the main distribution voltage is 660V.

Further, the secondary distribution voltage is 380V.

Compared with the prior art, the technical scheme of the application has the following beneficial technical effects:

1. according to the utility model, the frequency converter is arranged to control the oil pumping motor, so that the frequency modulation is realized to change the power of the oil pumping motor, the output power of the oil pumping motor is well matched, the high efficiency is kept under the condition of light load, the loss is low, the efficiency and the power factor are high, the oil pumping motor does not need to be replaced, the existing equipment is utilized to the maximum extent, the waste of the assets of the existing equipment is avoided, and the modification cost is reduced;

2. the main transformer is arranged to reduce the 1140V power supply voltage to 660V, so that the optimal cost of the frequency converter and the oil pumping motor is realized, and the field equipment assets are not wasted;

3. the voltage is reduced to 380V by the auxiliary transformer and is used for driving the cooling fan, and the situation of insufficient cooling during low-frequency operation is avoided due to the adoption of the independent cooling fan.

Drawings

Fig. 1 is a schematic structural diagram of a frequency conversion control system of an oil pumping unit according to an embodiment of the present invention;

FIG. 2 is a circuit diagram illustrating a connection manner of a main transformer and an auxiliary transformer according to an embodiment of the present invention;

FIG. 3 is a circuit structure diagram of the connection mode of the frequency converter and the oil pumping motor in the embodiment of the utility model;

fig. 4 is a circuit configuration diagram of a cooling fan connection mode according to an embodiment of the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

1. a three-phase 1140V power supply; 2. a main distribution voltage; 3. a secondary distribution voltage; 4. a main transformer; 5. a secondary transformer; 6. a frequency converter; 7. an oil pumping motor; 8. a cooling fan; 9. a PLC controller.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. The "connection" in the following embodiments is understood as "electrical connection", "communication connection", or the like if the connected circuits, modules, units, or the like have electrical signals or data transmission therebetween.

A frequency conversion control system of an oil pumping machine comprises a three-phase 1140V power supply 1, a main distribution voltage 2, an auxiliary distribution voltage 3, a frequency converter 6, an oil pumping motor 7 and a cooling fan 8. A main transformer 4 is arranged between the three-phase 1140V power supply 1 and the main distribution voltage 2, the primary end of the main transformer 4 is connected with the 1140V power supply 1, and the secondary end is connected with the main distribution voltage 2. An auxiliary transformer 5 is arranged between the main distribution voltage 2 and the auxiliary distribution voltage 3, the primary end of the auxiliary transformer 5 is connected with the main distribution voltage 2, and the secondary end is connected with the auxiliary distribution voltage 3.

In this embodiment, the main distribution voltage 4 is 660V, and is used for supplying power to the frequency converter 6 and the oil pumping motor 7. Under the 1140V voltage platform, the price difference of the frequency converter power device and the low-voltage frequency converter device is large, in order to meet the requirement of cost, the 1140V is reduced to 660V, and the price of the frequency converter 6 is relatively reasonable. Meanwhile, the related transformation and Y-delta transformation of the motor are carried out, and the rated voltage of the oil pumping motor 7 is reduced. Therefore, the main transformer 4 is arranged to reduce the 1140V three-phase alternating current to 660V, so that the cost of the frequency converter 46 and the oil pumping motor 7 is optimized, and the field equipment assets are not wasted.

The secondary distribution voltage 5 is 380V for supplying power to the cooling fan 8, and the secondary transformer 5 reduces 660V three-phase ac power to 380V. The cooling fan 8 is used for cooling the oil pumping motor 7. Due to the adoption of the independent cooling fan 7, the condition that the oil pumping motor 6 is not cooled sufficiently when running at low frequency can be avoided.

As shown in fig. 3, the input end of the frequency converter 6 is connected with the main distribution voltage 4, and the output end is connected with the oil pumping motor 7. Through frequency conversion transformation, the frequency converter 6 is installed to carry out frequency conversion control on the oil pumping motor 7, so that the oil pumping motor 7 runs in a frequency conversion mode, the output power of the oil pumping motor 7 is well matched, the oil pumping motor 7 can also keep higher efficiency under the condition of light load, the loss is low, the efficiency and the power factor are high, constant-torque starting is realized, starting failure is avoided, and the requirement on the characteristics of the oil pumping motor 7 for the ox and horse is met. In addition, the oil pumping motor 7 can continuously select the previous permanent magnet motor without being replaced by a switched reluctance motor, so that the existing equipment is utilized to the maximum extent, the waste of the assets of the existing equipment is avoided, and the cost of transformation is reduced. And a breaker QF1 is arranged between the input end of the frequency converter 6 and the main distribution voltage 4 to perform overload protection on the frequency converter 6 and the oil pumping motor 7.

As shown in fig. 4, cooling fan 8 is connected to sub-distribution voltage 5 via a thermal relay FR 1. When the cooling fan 8 fails, the rotational speed is decreased, the current is increased, and therefore the temperature of the thermal relay FR1 is increased. When the temperature of the thermal relay FR1 rises to exceed the allowable value, the circuit is opened, so that the cooling fan 8 stops working and the whole circuit is protected. A switch KM1 for controlling the operating state of the cooling fan 8 and a circuit breaker QF2 for overload protection of the cooling fan 8 are also connected in series between the thermal relay FR1 and the secondary distribution voltage 5.

Preferably, the utility model also comprises a PLC controller 9, a communication device and an alarm device. The PLC controller 9 is connected to the sub distribution voltage 5 and supplies power by a 380V three-phase ac voltage. And the PLC 9 is connected with the frequency converter 6 and the oil pumping motor 7. The alarm device is connected with the PLC 9 and used for alarming. The communication device is connected with the PLC 9 and is used for realizing the remote communication between the PLC 9 and the control center. The PLC 9 monitors the operation parameters of the pumping unit in real time, realizes local logic management, judges the operation conditions, and realizes automatic parameter adjustment or information management.

Specifically, the PLC controller 9 collects in real time the operating parameters of the pumping unit, such as current, voltage, frequency of stroke, temperature, flow rate, and operating state. Aiming at abnormal states, the PLC 9 carries out field logic management, if emergency shutdown is needed, the emergency shutdown is carried out, alarm information is sent to the alarm device, and the alarm device gives an alarm; when the emergency shutdown is not needed, the control center is informed in time through the communication device. The PLC 9 performs rationalization adjustment for automatically judging the number of strokes according to the current-diagram curve relationship. And the frequency converter 6 is used for carrying out frequency conversion control on the oil pumping motor 7. The PLC 9 also judges whether the oil pumping unit normally operates according to the indicator diagram curve.

In addition, the utility model is connected with the PLC 9 on site through the communication device, and can adopt the internet technology to carry out real-time data exchange, thereby realizing remote intelligent management. Meanwhile, based on the cloud server, the GIS system monitoring can be realized, the equipment operation information is subjected to hierarchical authorization management, and different terminals are adopted for state monitoring.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (8)

1. A frequency conversion control system of a pumping unit is characterized by comprising a three-phase 1140V power supply (1), a main distribution voltage (2), an auxiliary distribution voltage (3), a main transformer (4), an auxiliary transformer (5), a frequency converter (6), an oil pumping motor (7) and a cooling fan (8); the primary end of the main transformer (4) is connected with the three-phase 1140V power supply (1), and the secondary end is connected with the main distribution voltage (2); the primary end of the auxiliary transformer (5) is connected with the main distribution voltage (2), and the secondary end of the auxiliary transformer is connected with the auxiliary distribution voltage (3); the oil pumping motor (7) is connected with the main distribution voltage (2) through the frequency converter (6); the cooling fan (8) is connected with the auxiliary distribution voltage (3), and the cooling fan (8) is used for cooling the oil pumping motor (7).

2. The variable frequency control system of the oil pumping unit according to claim 1, characterized in that a thermal relay is connected in series between the auxiliary distribution voltage (3) and the cooling fan (8).

3. The variable frequency control system of the oil pumping unit according to claim 1, characterized by further comprising a PLC (9), wherein the PLC (9) is connected with the auxiliary distribution voltage (3); and the PLC (9) is connected with the oil pumping motor (7) and the frequency converter (6), and the frequency converter (6) is controlled by the working state of the oil pumping motor (7).

4. The variable frequency control system of the oil pumping unit according to claim 3, further comprising an alarm device, wherein the alarm device is connected with the PLC controller (9).

5. The variable frequency control system of the oil pumping unit according to claim 3, further comprising a communication device, wherein the communication device is connected with the PLC (9) and is used for real-time data exchange with a control center.

6. The variable frequency control system of the oil pumping unit according to claim 1, wherein the oil pumping motor (7) is a permanent magnet motor.

7. A variable frequency control system for a pumping unit according to claim 1, characterized in that the main distribution voltage (2) is 660V.

8. A variable frequency control system for a pumping unit according to claim 1, characterized in that the secondary distribution voltage (3) is 380V.

Images