Pumping unit energy storage device, cabinet and pumping unit control device

Abstract

The invention provides a pumping unit energy storage device, a cabinet and a pumping unit control device, and relates to the field of oil exploitation, and the pumping unit energy storage device comprises a super capacitor module which is used for being electrically connected with one end of a frequency conversion module; wherein the other end of the frequency conversion module is electrically connected with the driving motor, and the driving motor is used for driving the oil pumping unit. The driving motor has a power generation state that the driving motor is reversely driven by the oil pumping unit to rotate to generate power in the process of driving the oil pumping unit; the super capacitor module is used for storing electric energy generated by the driving motor in the power generation state through the frequency conversion module; the super capacitor module is used for transmitting the stored electric energy to the driving motor through the frequency conversion module so as to drive the pumping unit to operate.

Description

Technical Field

[0001] The present application relates to the field of oil extraction, and particularly to an energy storage device for a pumping unit, a cabinet and a control device for a pumping unit. Background Art

[0002] Most of the pumping units currently applied in the on-site coalbed methane drainage and gas production are beam pumping units. Based on the motion structure of the beam pumping unit and the working characteristics of the oil pump, it is determined that within one working stroke, the driving motor will be in a power generation state once, that is, the phenomenon of the pumping unit generating electricity in reverse. In this case, the energy generated in reverse is injected into the power grid, which will impact the power grid, cause energy waste, and increase production costs. Summary of the Invention

[0003] The present application provides an energy storage device for a pumping unit, a cabinet and a control device for a pumping unit, which can solve the technical problems that the energy cannot be effectively utilized in the phenomenon of the pumping unit generating electricity in reverse, resulting in low power consumption efficiency of the pumping unit and increased production costs.

[0004] In the first aspect of the present application, an energy storage device for a pumping unit is provided, including

[0005] A supercapacitor module, electrically connected to one end of a frequency conversion module;

[0006] Wherein, the other end of the frequency conversion module is electrically connected to a driving motor, the driving motor is used to drive the pumping unit, and the driving motor is in a power generation state of being driven to rotate in reverse by the pumping unit during the process of driving the pumping unit;

[0007] The supercapacitor module is used to store the electric energy generated by the driving motor in the power generation state through the frequency conversion module, and the supercapacitor module is used to transmit the stored electric energy to the driving motor through the frequency conversion module to drive the operation of the pumping unit.

[0008] In some embodiments, the energy storage device for the pumping unit further includes:

[0009] A power-on buffer unit, connected in series to the DC bus, and the supercapacitor module and the frequency conversion module are electrically connected through the DC bus;

[0010] A control unit, electrically connected to the positive and negative poles of the DC bus respectively;

[0011] Wherein, the power-on buffer unit is used to limit the initial starting current of the supercapacitor module, and the control unit is used to detect the pressure difference of the DC bus and control the working state of the power-on buffer unit to enable the supercapacitor module to start normally when the pressure difference reaches the threshold.

[0012] In some embodiments, the power-on buffer unit includes:

[0013] A first buffer contactor, connected in series to the DC bus;

[0014] A second buffer contactor, connected in parallel with the first buffer contactor;

[0015] A buffer resistor, connected in series with the first buffer contactor;

[0016] Wherein, when the voltage difference across the DC bus reaches the threshold, the control unit is further configured to control the first buffer contactor to disconnect and control the second buffer contactor to close.

[0017] In some embodiments, the control unit is electrically connected to the supercapacitor module;

[0018] Wherein, the control unit is further configured to detect a fault signal of the supercapacitor module and, when the fault signal is detected, control the second buffer contactor to disconnect.

[0019] In some embodiments, the pumping unit energy storage device further includes:

[0020] A braking unit, electrically connected to the positive and negative poles of the DC bus respectively, and the supercapacitor module and the frequency conversion module are electrically connected through the DC bus;

[0021] A dissipating resistor, one end of which is electrically connected to the DC bus and the other end of which is electrically connected to the braking unit;

[0022] Wherein, the braking unit is configured to detect the voltage difference across the DC bus and, when the detected voltage difference is greater than the rated voltage of the supercapacitor module, control the dissipating resistor to be connected in parallel to the DC bus.

[0023] In some embodiments, the pumping unit energy storage device further includes:

[0024] A first circuit breaker, forming an open circuit with the dissipating resistor, and the open circuit is connected in parallel to the DC bus; and / or,

[0025] A second circuit breaker, connected in series to the positive pole of the DC bus, and the outgoing line end of the second circuit breaker is electrically connected to the braking unit.

[0026] In some embodiments, the pumping unit energy storage device further includes:

[0027] A DC metering unit, communicatively connected to the control unit and electrically connected to the DC bus;

[0028] Wherein, the DC metering unit is used to detect the current of the DC bus and send the detection result to the control unit.

[0029] In some embodiments, the supercapacitor module includes a plurality of series-connected single capacitors.

[0030] A second aspect of the present application provides a cabinet, including:

[0031] A cabinet body;

[0032] The pumping unit energy storage device as described in any one of the first aspect;

[0033] Wherein, the supercapacitor module is arranged in a part of the cabinet body close to the ground.

[0034] A third aspect of the present application provides a pumping unit control device, including:

[0035] A pumping unit;

[0036] A driving motor, electrically connected to the pumping unit;

[0037] A frequency conversion module, electrically connected to the driving motor;

[0038] The pumping unit energy storage device as described in any one of the first aspect, and the pumping unit storage device is electrically connected to the frequency conversion module.

[0039] In summary, the pumping unit energy storage device provided by the present application includes: a supercapacitor module, which is used to be electrically connected to one end of a frequency conversion module; wherein, the other end of the frequency conversion module is electrically connected to a driving motor, and the driving motor is used to drive the pumping unit. During the process of driving the pumping unit, the driving motor has a power generation state where it is reversely driven by the pumping unit to rotate and generate electricity. The supercapacitor module is used to store the electric energy generated when the driving motor is in the power generation state through the frequency conversion module, and the supercapacitor module is used to transmit the stored electric energy to the driving motor through the frequency conversion module to drive the pumping unit to operate. In the present application, by electrically connecting the supercapacitor module to the frequency conversion module connected to the driving motor, when the pumping unit generates electricity in reverse during one working stroke, that is, when the driving motor is in the power generation state, the generated alternating current is converted into direct current through the frequency conversion module and stored in the supercapacitor module. During one working stroke, when the pumping unit is not in reverse power generation, that is, when the driving motor is in the electric state, the supercapacitor module can send out the stored electric energy for the driving motor to drive the pumping unit. Therefore, the energy storage device provided by the present application can absorb energy when the pumping unit generates electricity in reverse, eliminate the impact on the power grid, and when the pumping unit is not in reverse power generation, it can also transfer the stored energy to the driving motor to drive the pumping unit to work, thereby improving the power consumption efficiency of the pumping unit and reducing the production cost.

[0040] Accordingly, the cabinet and the pumping unit control device provided by the present application also have the above technical effects. Description of the Drawings

[0041] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, throughout the drawings, the same reference numerals are used to denote the same components. In the drawings:

[0042] Figure 1 is an application schematic diagram of a pumping unit energy storage device provided by an embodiment of the present application;

[0043] Figure 2 is a schematic structural diagram of a pumping unit energy storage device provided by an embodiment of the present application;

[0044] Figure 3 is a working flow chart of a pumping unit energy storage device provided by an embodiment of the present application;

[0045] Figure 4 is a floor plan of a cabinet provided by an embodiment of the present application;

[0046] Among them, Figure 1 、 Figure 2 and Figure 4 the corresponding relationship between the reference numerals and the component names in is:

[0047] 10 Cabinet;

[0048] 100 Pumping unit energy storage device 100, 200' Frequency conversion module, 300' Drive motor, 400' Pumping unit, 500 Cabinet body;

[0049] 110 Supercapacitor module 110, 120 Power-on buffer unit, 130 Control unit, 140 Braking unit, 150 Energy-consuming resistor, 160 First circuit breaker, 170 Second circuit breaker, 180 DC metering unit;

[0050] 121 First buffer contactor, 122 Second buffer contactor, 123 Buffer resistor, 131 Micro control unit, 132 Isolated control power supply, 181 DC shunt, 182 DC metering module. Detailed Embodiments

[0051] To better understand the above technical solution, the technical solution of the embodiments of the present application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present application and the embodiments are detailed descriptions of the technical solution of the embodiments of the present application, rather than limitations on the technical solution of the present application. Without conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0052] In the first aspect of the embodiments of the present application, a pumping unit energy storage device is provided. Figure 1 The following is an application schematic diagram of a pumping unit energy storage device provided by the embodiments of the present application. As Figure 1 shown, the above-mentioned pumping unit energy storage device 100 includes: a supercapacitor module 110, which is electrically connected to one end of a frequency conversion module 200'. The other end of the frequency conversion module 200' is electrically connected to a drive motor 300'. The drive motor 300' is used to drive a pumping unit 400'. During the process of driving the pumping unit 400', the drive motor 300' has a power generation state where it is driven to rotate in the reverse direction by the pumping unit 400' to generate electricity. The supercapacitor module 110 is used to store the electric energy generated when the drive motor 300' is in the power generation state through the frequency conversion module 200'. The supercapacitor module 110 is used to transmit the stored electric energy to the drive motor 300' through the frequency conversion module 200' to drive the pumping unit 400' to operate.

[0053] The pumping unit 400' is driven by the drive motor 300'. The drive motor 300' is electrically connected to the supercapacitor module 110 through the frequency conversion module 200'. Considering the actual requirements in the oil extraction field, currently, the drive motor 300' mostly uses an AC motor. In actual production work, within one working stroke, when the rotational speed of the rotor of the drive motor 300' exceeds the synchronous speed of the motor, the net torque of the crank of the pumping unit 400' is negative, and the pumping unit 400' drives the drive motor 300' to operate. At this time, the drive motor 300' is in the power generation state. And because in the oil extraction field, the drive motor 300' is mostly powered by the power grid, so when the drive motor 300' is in the power generation state, the generated energy will be fed back to the power grid, that is, the reverse power generation phenomenon. This reverse power generation phenomenon will impact the stability of the power grid. At the same time, it will cause energy waste and lead to an increase in production costs.

[0054] To address this phenomenon, in related technologies, one category is to optimize the mechanical structure and control means of the pumping unit 400' to adjust the crank speed of the pumping unit 400' and eliminate the negative torque of the crank. Furthermore, by setting a heating resistor, the heat generated by the heating resistor is used to consume the energy generated by the reverse power generation. However, for these two types of methods, firstly, the workload is large and the transformation construction period is long. Secondly, the problem of energy waste is not completely solved.

[0055] To solve the above technical problems, in the embodiments of the present application, the supercapacitor module 110 is electrically connected to the frequency conversion module 200' that drives the drive motor 300'. When the pumping unit 400' generates reverse power within one working stroke, that is, when the drive motor 300' is in the power generation state, the generated alternating current is converted into direct current by the frequency conversion module 200' and stored in the supercapacitor module 110. When the pumping unit 400' is not generating reverse power within one working stroke, that is, when the drive motor 300' is in the electric state, the supercapacitor module 110 can send out the stored electric energy for the drive motor 300' to drive the pumping unit 400'. Therefore, the energy storage device provided by the embodiments of the present application can absorb energy when the pumping unit 400' generates reverse power, eliminating the impact on the power grid, and when the pumping unit 400' is not generating reverse power, it can transfer the stored energy to the drive motor 300' to drive the pumping unit 400' to work, thereby improving the power consumption efficiency of the pumping unit 400' and reducing the production cost.

[0056] It should be noted that the supercapacitor module 110 has a very high capacitance, higher energy density compared to ordinary capacitors. Since it stores electrical energy jointly by the electrode plates and the dielectric, it has the characteristics of fast charge and discharge, long life, high cycle times, etc. The pumping unit 400' requires a large working power, and the drive motor 300' generates more energy accordingly. Therefore, the supercapacitor module 110 can give full play to its own characteristics and is very suitable for this scenario.

[0057] In some examples, when the drive motor 300' is an AC synchronous permanent magnet motor, since the permanent magnet motor provides a constant additional magnetic field through the permanent magnets, when the pumping unit 400' is in the reverse power generation state, the generated energy is basically generated by the drive of the torque. Therefore, the supercapacitor module 110 can store basically all the generated energy, so that the power consumption efficiency of the pumping unit 400' is further improved compared to the AC asynchronous motor.

[0058] According to some embodiments, Figure 2 is a schematic structural diagram of an energy storage device for a pumping unit provided by the embodiments of the present application. As Figure 2 shown, the above-mentioned energy storage device 100 for a pumping unit further includes: a power-on buffer unit 120, connected in series to the DC bus, where DC+ and DC- respectively represent the positive and negative poles of the DC bus. The supercapacitor module 110 is electrically connected to the frequency conversion module 200' through the DC bus; a control unit 130, electrically connected to the positive and negative poles of the DC bus respectively; wherein, the power-on buffer unit 120 is used to limit the initial start-up current of the supercapacitor module 110, and the control unit 130 is used to detect the voltage difference of the DC bus and control the working state of the power-on buffer unit 120 to enable the supercapacitor module 110 to start normally when the voltage difference reaches the threshold.

[0059] It should be noted that the supercapacitor module 110 and the frequency conversion module 200' can be electrically connected via a DC bus. At the same time, in order to prevent the supercapacitor module 110 from being broken down by excessive current during initial startup, a power-on buffer unit 120 is provided to limit the initial startup current of the supercapacitor module 110. At the same time, a control unit 130 is also provided, which is electrically connected to the positive and negative electrodes of the DC bus to detect the voltage difference of the DC bus. When the voltage difference reaches a threshold, the working state of the power-on buffer unit 120 is controlled to enable the supercapacitor module 110 to start normally.

[0060] It is understandable that the threshold is usually less than the maximum voltage of the frequency conversion module 200', and the specific value can be determined according to actual conditions without limitation. The normal startup refers to releasing the current limitation of the DC bus by the power-on buffer unit 120.

[0061] In some examples, such as Figure 2 As shown, the control unit 130 may include an MCU (Microcontroller Unit), and the positive and negative interfaces of the microcontroller 131 are connected to the positive and negative electrodes of the DC bus, respectively. At the same time, the control unit 130 may also include an isolated control power supply 132, and IN+ and IN- of the isolated control power supply 132 are electrically connected to the positive and negative electrodes of the DC bus, respectively, and OUT+ and OUT- are electrically connected to the positive and negative interfaces of the positive and negative interfaces of the microcontroller 131, respectively. The isolated control power supply 132 is used to provide power to the microcontroller 131.

[0062] In some examples, the control unit 130 may also be electrically connected to any phase of the drive motor 300 ′, such as Figure 2 Since the line voltage of the driving electrode is tested to be normal, when the line voltage is normal, the working state of the power-on buffer unit 120 is controlled to enable the super capacitor module 110 to start normally.

[0063] According to some embodiments, Figure 2 The power-on buffer unit 120 includes: a first buffer contactor 121, connected in series to the DC bus; a second buffer contactor 122, connected in parallel to the first buffer contactor 121; and a buffer resistor 123, connected in series to the first buffer contactor 121; wherein, when the voltage difference of the DC bus reaches a threshold, the control unit 130 is also used to control the first buffer contactor 121 to open, and control the second buffer contactor 122 to close.

[0064] Exemplarily, before the above-mentioned supercapacitor module 110 is started for the first time, the first buffer contactor 121 is in a closed state, and the buffer resistor 123 is connected to the above-mentioned DC bus, so as to limit the starting current of the supercapacitor module 110 by setting a resistor. At the same time, when the control unit 130 detects that the voltage difference of the above-mentioned DC bus reaches the above-mentioned threshold, it controls the second buffer contactor 122 to close and the first buffer to open, so that the buffer resistor 123 is open-circuited, so that the supercapacitor can store or release energy normally.

[0065] It is easy to understand that the supercapacitor module 110 can be in a "fully charged and half discharged" working state to ensure adaptability to a variety of drive motors 300'.

[0066] According to some embodiments, as Figure 2 shown, the control unit 130 is electrically connected to the supercapacitor module 110. Among them, the control unit 130 is further configured to detect a fault signal of the supercapacitor module 110, and control the second buffer contactor 122 to disconnect when a fault signal is detected.

[0067] Exemplarily, the control unit 130 can be a micro control unit 131. The C interface of the micro control unit 131 is electrically connected to the SIG interface of the supercapacitor module 110, and the GND interface of the micro control unit 131 is electrically connected to the GND interface of the supercapacitor module 110. The above-mentioned fault signals include faults such as overheating and overvoltage. If a fault signal is detected, the second buffer contactor 122 is disconnected to protect the supercapacitor by power-off.

[0068] According to some embodiments, as Figure 2 shown, the above-mentioned pumping unit energy storage device 100 further includes: a braking unit 140, which is electrically connected to the positive and negative poles of the DC bus respectively; one end of a power-consuming resistor 150 is electrically connected to the DC bus, and the other end is electrically connected to the braking unit 140; wherein, the braking unit 140 is configured to detect the voltage difference of the DC bus, and control the power-consuming resistor 150 to be connected in parallel to the DC bus when the detected voltage difference is greater than the rated voltage of the supercapacitor module 110.

[0069] It should be noted that the supercapacitor module 110 is electrically connected to the frequency conversion module 200' through the DC bus. When the braking unit 140 detects that the voltage difference of the above-mentioned DC bus is greater than the rated voltage of the supercapacitor module 110, it connects the power-consuming resistor 150 in parallel to the DC bus, so as to use the power-consuming resistor 150 to reduce the voltage across the supercapacitor module 110 and prevent the supercapacitor module 110 from being broken down.

[0070] Exemplarily, when the braking unit 140 can be a dedicated energy feedback unit for a frequency converter, the power-consuming resistor can be connected through the PB interface to control the power-consuming resistor.

[0071] According to some embodiments, as Figure 2 shown, the pumping unit energy storage device 100 further includes a first circuit breaker 160. The first circuit breaker 160 forms an open circuit with the energy-consuming resistor 150, and the open circuit is connected in parallel to the DC bus; and / or, a second circuit breaker 170, which is connected in series to the positive pole of the DC bus, and the outgoing line end of the second circuit breaker 170 is electrically connected to the braking unit 140.

[0072] Exemplarily, the pumping unit energy storage device 100 may further include a first circuit breaker 160. The first circuit breaker 160 is connected in series with the energy-consuming resistor 150 and then connected in parallel to the DC bus, and forms an open circuit when the supercapacitor module 110 is operating normally.

[0073] It should be noted that in some cases, when the braking unit 140 cannot operate normally, the first circuit breaker 160 can be closed manually, so that the energy-consuming resistor 150 can be connected in parallel to the DC bus to reduce the voltage across the supercapacitor module 110 and prevent the supercapacitor module 110 from being broken down.

[0074] Exemplarily, the pumping unit energy storage device 100 further includes a second circuit breaker 170. The second circuit breaker 170 is connected to the positive pole of the DC bus, and its outgoing line end is electrically connected to the braking unit 140.

[0075] It should be noted that the second circuit breaker 170 can act as a main circuit breaker and be connected to the positive pole, which can better protect the circuit and equipment.

[0076] According to some embodiments, as Figure 2 shown, the pumping unit energy storage device 100 further includes: a DC metering unit 180, which is communicatively connected to the control unit 130 and electrically connected to the DC bus; wherein, the DC metering unit 180 is used to detect the current of the DC bus and send the detection result to the control unit 130.

[0077] Exemplarily, as Figure 2 shown, the DC metering unit 180 may include a DC shunt 181 and a DC metering module 182. The DC shunt 181 shunts the current in the DC bus, and the DC metering module 182 detects the current of the DC bus by detecting the shunted current and sends the detection result to the control unit 130.

[0078] It should be noted that the control unit 130 can detect the reverse power generation amount of the pumping unit 400' based on the above detection result, and through analysis and judgment, to realize intelligent monitoring of the operating state of the pumping unit 400' and give an early warning of the abnormal operation of the pumping unit 400'.

[0079] According to some embodiments, the super capacitor module 110 includes a plurality of single capacitors connected in series.

[0080] For example, Figure 2 As shown, the structure of the supercapacitor module 110 can be a plurality of single supercapacitors connected in series, adopting a series structure, such as supercapacitor C1, supercapacitor C2, supercapacitor C3 and supercapacitor C4. The series structure can reduce the voltage of each supercapacitor, thereby improving the overall pressure resistance of the supercapacitor module 110 and improving the service life of the device.

[0081] Combine the following Figure 2 and Figure 3 The working process of the oil pumping unit energy storage device 100 provided in the embodiment of the present application is introduced. Figure 3 A working diagram of an oil pumping unit energy storage device 100 provided in an embodiment of the present application is as follows:

[0082] Step S1: Q1 is switched on and MCU is powered on. Q1 is the second circuit breaker 170 and MCU is the control unit 130. In step S1, the super capacitor module 110 is self-checked to see if it is normal. If so, step S2 is executed, otherwise step S3 is executed.

[0083] Step S2: Start the start / stop knob, that is, close the first buffer. The MCU determines whether the three-phase voltage of the DC bus and the external drive motor 300' is normal. If so, close the power-on buffer contactor KM1. If not, further determine whether the operating state of the pumping unit 400' is abnormal. If yes, execute step S9. KM1 is the first buffer contactor 121.

[0084] Step S3: System failure, try to reset the failure. The super capacitor module 110 can be shut down for inspection.

[0085] Step S4: close the power-on buffer contactor KM1 to limit the initial startup of the super capacitor module 110 to prevent excessive current. After the voltage across the super capacitor module 110 reaches the rated voltage, execute step S5.

[0086] Step S5: close the power-on buffer contactor KM2, and open the power-on buffer contactor KM1 to release the restriction on the supercapacitor transmission current. KM2 is the second buffer contactor 122. At the same time, the MCU can detect whether the supercapacitor module 110 reports a fault. If the voltage of the supercapacitor module 110 is too high, step S8 is executed. If it is not a fault of too high voltage, step S3 is executed. If the brake unit 140 fails, step S6 is executed.

[0087] Step S6: Q1 is opened to disconnect the circuit between the frequency conversion module 200 ′ and the super capacitor module 110 .

[0088] Step S7: Close Q2, and divide the voltage of the supercapacitor module 110 through the energy-consuming resistor 150, where Q2 is the first circuit breaker 160 mentioned above.

[0089] Step S8: The braking unit 140 is put into operation to release pressure.

[0090] Step S9: Determine that the pumping unit 400' is abnormal, and an alarm can be sent through the MCU.

[0091] The second aspect of the present application provides a cabinet 10. Figure 4 It is a schematic layout diagram of a cabinet provided by an embodiment of the present application. As Figure 4 shown, the above-mentioned cabinet 10 includes: a cabinet body 500; a pumping unit energy storage device 100 according to any one of the first aspects, wherein the supercapacitor module 110 device is arranged in a part of the cabinet body 500 close to the ground.

[0092] Exemplarily, as Figure 4 shown, the energy-consuming resistor 150 plays a role in voltage division. Since its size is relatively large, it can be arranged at the upper end of the above-mentioned cabinet body 500. The supercapacitor module 110 is placed in a part of the cabinet body 500 close to the ground due to its relatively large volume and the reason that the supercapacitor module 110 includes a dielectric, ensuring safety. Figure 4 In it, MCU represents the control unit 130, BU represents the braking unit 140, and both usually need to be powered and can be arranged side by side. Q1 and Q2 respectively represent the second circuit breaker 170 and the first circuit breaker 160, KM1 and KM2 respectively represent the first buffer contactor 121 and the second buffer contactor 122, R1 represents the buffer resistor 123, U represents the isolation control power supply 132, PJ represents the DC metering module 182, and CT represents the DC shunt 181. These devices have a small volume and can be arranged in a row.

[0093] The third aspect of the present application provides a pumping unit control device, including: a pumping unit; a driving motor electrically connected to the pumping unit; a frequency conversion module electrically connected to the driving motor; a pumping unit energy storage device 100 according to any one of the first aspects, and the pumping unit storage device is electrically connected to the frequency conversion module 200'.

[0094] Exemplarily, the above-mentioned driving motor can be an AC synchronous permanent magnet motor. Since the permanent magnet motor provides a constant additional magnetic field through permanent magnets, when the pumping unit is in the reverse power generation state, the generated energy is basically generated by the drive of the torque. Therefore, the supercapacitor module 110 can store basically all the generated energy, so that the power consumption efficiency of the pumping unit is further improved compared with the AC asynchronous motor.

[0095] In this application, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "plural" means two or more, unless otherwise clearly defined. Terms such as "installed", "connected", "joined", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "joined" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0096] In the description of this application, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0097] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0098] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. An energy storage device for a pumping unit, characterized in that, it includes: A supercapacitor module for electrically connecting to one end of a frequency conversion module; Wherein, the other end of the frequency conversion module is electrically connected to a drive motor, the drive motor is used to drive the pumping unit, and the drive motor has a power generation state in which it is driven to rotate in reverse by the pumping unit during the process of driving the pumping unit; The supercapacitor module is used to store the electric energy generated by the drive motor in the power generation state through the frequency conversion module, and the supercapacitor module is used to transmit the stored electric energy to the drive motor through the frequency conversion module to drive the operation of the pumping unit.

2. The energy storage device for a pumping unit according to claim 1, characterized in that, it further includes: A power-on buffer unit, the supercapacitor module and the frequency conversion module are electrically connected through a DC bus, and the power-on buffer unit is connected in series to the DC bus; A control unit, electrically connected to the positive and negative poles of the DC bus respectively; Wherein, the power-on buffer unit is used to limit the first startup current of the supercapacitor module, and the control unit is used to detect the pressure difference of the DC bus, and when the pressure difference reaches the threshold, control the working state of the power-on buffer unit to enable the supercapacitor module to start normally.

3. The energy storage device for a pumping unit according to claim 2, characterized in that, the power-on buffer unit includes: A first buffer contactor, connected in series to the DC bus; A second buffer contactor, connected in parallel with the first buffer contactor; A buffer resistor, connected in series with the first buffer contactor; Wherein, when the pressure difference of the DC bus reaches the threshold, the control unit is further used to control the first buffer contactor to disconnect and control the second buffer contactor to close.

4. The energy storage device for a pumping unit according to claim 3, characterized in that, the control unit is electrically connected to the supercapacitor module; Wherein, the control unit is further used to detect the fault signal of the supercapacitor module, and when the fault signal is detected, control the second buffer contactor to disconnect.

5. The energy storage device for a pumping unit according to claim 1, characterized in that, it further includes: A braking unit, electrically connected to the positive and negative poles of the DC bus respectively, and the supercapacitor module and the frequency conversion module are electrically connected through the DC bus; A power-consuming resistor, one end is electrically connected to the DC bus, and the other end is electrically connected to the braking unit; Wherein, the braking unit is used to detect the pressure difference of the DC bus, and when it detects that the pressure difference is greater than the rated voltage of the supercapacitor module, control the power-consuming resistor to be connected in parallel to the DC bus.

6. The energy storage device for a pumping unit according to claim 5, characterized in that, it further includes: A first circuit breaker, forming an open circuit with the power-consuming resistor, and the open circuit is connected in parallel to the DC bus; and / or, A second circuit breaker, connected in series to the positive pole of the DC bus, and the outgoing line end of the second circuit breaker is electrically connected to the braking unit.

7. The energy storage device for a pumping unit according to claim 2, characterized in that, it further includes: A DC metering unit, communicatively connected to the control unit and electrically connected to the DC busbar; wherein the DC metering unit is configured to detect the current of the DC busbar and send the detection result to the control unit.

8. The pumping unit energy storage device according to any one of claims 1-7, characterized in that the supercapacitor module includes a plurality of series-connected single capacitors.

9. A cabinet, characterized in that it includes: a cabinet body; the pumping unit energy storage device according to any one of claims 1-8.

10. A pumping unit control device, characterized in that it includes: a pumping unit; a driving motor, electrically connected to the pumping unit; a frequency conversion module, electrically connected to the driving motor; the pumping unit energy storage device according to any one of claims 1-8, and the pumping unit storage device is electrically connected to the frequency conversion module.

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