Intelligent oil pumping unit system and control method

Abstract

The invention discloses an intelligent oil pumping unit system and a control method, the intelligent oil pumping unit system comprises N oil pumping units, first ends of the N oil pumping units are connected with an alternating current power supply, second ends of the N oil pumping units are used for supplying power to corresponding motors, direct current buses of the N oil pumping units are connected in parallel, and the N oil pumping units comprise at least one intelligent oil pumping unit; the intelligent pumping unit comprises a rectifying circuit, a frequency conversion circuit, a controller, an inverter circuit, a battery pack and a first protection circuit, and in order to recycle energy generated in the operation process of a motor, the controller is used for controlling the first protection circuit to work when at least one pumping unit in the N pumping units is in the down stroke, so that the battery pack stores excess energy of a direct-current bus; energy recovery is effectively achieved, and energy consumption of the intelligent pumping unit system is reduced.

Description

[0001] This disclosure claims priority to Chinese Patent Application No. 202510350703.5, filed on March 24, 2025, entitled "An Elevator Energy-Saving Control System and Control Method", and to Chinese Patent Application No. 2025112284784, filed on August 29, 2025, entitled "An Elevator Energy-Saving Control System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of intelligent control technology, specifically to an intelligent oil pumping unit system and control method. Background Technology

[0003] The oil pumping unit is the core equipment in oil extraction, mainly consisting of a counterweight, a pumping head, and a motor. The motor drives the pumping head to complete the reciprocating motion of the upstroke and downstroke, enabling the extraction of oil from the formation. The counterweight moves downwards during the upstroke to assist the motor in doing work; during the downstroke, it moves upwards to store energy for release during the upstroke.

[0004] In existing oil pumping units, the motor generates regenerative energy during operation. However, this regenerative energy is typically dissipated as heat through braking resistors, making effective recovery impossible. Therefore, existing oil pumping units cannot effectively achieve energy recovery, resulting in high energy consumption. Summary of the Invention

[0005] In view of this, this application provides an intelligent oil pumping unit system and control method that can effectively realize energy recovery and reduce energy consumption.

[0006] To solve the above problems, the technical solution provided in this application is as follows: This application provides an intelligent oil pumping unit system, comprising: N oil pumping units, where N is an integer greater than or equal to 2; the first ends of the N oil pumping units are connected to an AC power source, and the second ends of the N oil pumping units are used to power corresponding motors; the DC buses of the N oil pumping units are connected in parallel; at least one of the N oil pumping units is an intelligent oil pumping unit; the intelligent oil pumping unit includes a rectifier circuit, a frequency converter circuit, a controller, an inverter circuit, a battery pack, and a first protection circuit; the DC side and AC side of the inverter circuit are respectively connected to the DC bus and the AC power source; the two ends of the frequency converter circuit are respectively connected to the DC bus and the corresponding motor; the AC side of the rectifier circuit is connected to the AC power source, and the DC side of the rectifier circuit is connected to the DC bus via the first protection circuit; the DC bus is also used to connect the battery pack; the controller is used to control the first protection circuit to operate during the downstroke of at least one oil pumping unit, so that the battery pack stores excess energy from the DC bus.

[0007] In one possible implementation, the intelligent pumping unit further includes a first balance block; the controller is configured to adjust the first balance block when the first ratio of the upstroke power to the downstroke power of the intelligent pumping unit is less than a first ratio threshold or greater than a second ratio threshold, until the first ratio is greater than the first ratio threshold and less than the second ratio threshold; the first ratio threshold is less than the second ratio threshold.

[0008] In one possible implementation, the intelligent oil pump also includes a donkey head; the battery pack and the first counterweight are integrated together; or, the battery pack is placed at the tail of the intelligent oil pump, and the donkey head is close to the head of the intelligent oil pump.

[0009] One possible implementation is that N pumping units include M intelligent pumping units and NM ordinary pumping units; M is an integer greater than or equal to 1; each ordinary pumping unit includes a detection circuit and a second balancing block; the detection circuit is used to detect the upstroke power and downstroke power of the corresponding ordinary pumping unit; the controller is used to adjust the second balancing block when the second ratio of the upstroke power and downstroke power of the ordinary pumping unit is less than the first ratio threshold or greater than the second ratio threshold, until the second ratio is greater than the first ratio threshold and less than the second ratio threshold.

[0010] In one possible implementation, the conventional pumping unit further includes a second protection circuit; the first and second protection circuits include a positive protection circuit, or the first and second protection circuits include positive and negative protection circuits; both the positive and negative protection circuits include a charging circuit, and both include a discharging circuit; in the positive protection circuit, the DC side of the rectifier circuit is connected to the positive DC bus sequentially through the charging circuit and the discharging circuit; in the positive and negative protection circuits, the DC side of the rectifier circuit is connected to the positive DC bus through the discharging circuit, and the DC side of the rectifier circuit is connected to the negative DC bus through the charging circuit; the controller is used to control both the charging circuit and the discharging circuit to provide a path when the battery pack is not faulty, so that the battery pack stores excess energy of the DC bus during the downstroke of at least one pumping unit.

[0011] In one possible implementation, the charging circuit includes a first switch and a first diode, with a first terminal of the first switch connected to the negative terminal of the first diode and a second terminal of the first switch connected to the positive terminal of the first diode; the discharging circuit includes a second switch and a second diode; in the positive protection circuit, the first terminal of the second switch is connected to the positive terminal of the second diode and the second terminal of the first switch, the second terminal of the second switch is connected to the negative terminal of the second diode, and the positive terminal of the second diode is connected to the positive terminal of the first diode; the DC side of the rectifier circuit is connected to the positive DC bus via the first switch and the second switch in sequence; in the positive and negative protection circuit, the first terminal of the second switch is connected to the negative terminal of the second diode, and the second terminal of the second switch is connected to the positive terminal of the second diode; the DC side of the rectifier circuit is connected to the positive DC bus via the second switch, and the DC side of the rectifier circuit is connected to the negative DC bus via the first switch; the controller is used to control the first switch and the second switch to close when the battery pack is not faulty, so that the battery pack stores excess energy of the DC bus during the downstroke of at least one pumping unit.

[0012] In one possible implementation, the first protection circuit of the main intelligent pumping unit among the M intelligent pumping units is either the positive protection circuit or the positive and negative protection circuit; when the non-crossing voltage difference of the voltage range of at least one intelligent pumping unit among the M-1 intelligent pumping units is less than the voltage difference threshold, and the non-crossing voltage difference between the voltage range of the at least one intelligent pumping unit and the DC bus voltage range of the main intelligent pumping unit is less than the voltage difference threshold, the protection circuit of the at least one intelligent pumping unit is either the positive protection circuit or the positive and negative protection circuit; when the non-crossing voltage difference of the voltage range of at least one ordinary pumping unit among the NM ordinary pumping units is less than the voltage difference threshold, and the non-crossing voltage difference between the voltage range of the at least one ordinary pumping unit and the DC bus voltage range of the intelligent pumping unit is less than the voltage difference threshold, the protection circuit of the at least one ordinary pumping unit is either the positive protection circuit or the positive and negative protection circuit.

[0013] In one possible implementation, the conventional pumping unit further includes a second protection circuit; both the first and second protection circuits include a DC / DC circuit; the DC side of the rectifier circuit is connected to the positive DC bus via the DC / DC circuit; the controller is used to control the operation of the DC / DC circuit and adjust the input current of the DC / DC circuit when the battery pack is not faulty, so that the battery pack stores excess energy of the DC bus during the downstroke of at least one pumping unit.

[0014] One possible implementation is that, when the non-crossing voltage difference of the voltage range of at least one of the M-1 intelligent pumping units is less than the voltage difference threshold, and the non-crossing voltage difference between the voltage range of the at least one intelligent pumping unit and the DC bus voltage range of the main intelligent pumping unit is greater than or equal to the voltage difference threshold, the protection circuit of the at least one intelligent pumping unit is the DC / DC circuit; when the non-crossing voltage difference of the voltage range of at least one of the NM ordinary pumping units is less than the voltage difference threshold, and the non-crossing voltage difference between the voltage range of the at least one ordinary pumping unit and the DC bus voltage range of the intelligent pumping unit is greater than or equal to the voltage difference threshold, the protection circuit of the at least one ordinary pumping unit is the DC / DC circuit.

[0015] One possible implementation is as follows: when the excess energy generated by the N pumping units is greater than the total power consumption of the N pumping units, and the battery pack is fully charged, the controller controls the inverter circuit to operate, feeding the excess energy from the DC bus back to the AC power supply; or, when the excess energy generated by the N pumping units is equal to the total power consumption of the N pumping units, and the battery pack is not discharged, the controller controls the inverter circuit to operate, feeding the energy stored in the battery pack back to the AC power supply until the energy of the battery pack is less than or equal to the discharge threshold; or, when the excess energy generated by the N pumping units is less than or equal to the total power consumption of the N pumping units, the controller controls the rectifier circuit to operate, using the AC power supply to charge the battery pack until the energy of the battery pack is greater than or equal to the charging threshold.

[0016] In one possible implementation, the controller is configured to, in the event of an overcharge fault in the battery pack, control each discharge circuit connected to the DC bus to provide a path, control each charging circuit connected to the DC bus to disconnect, and control each DC / DC circuit connected to the DC bus to be in a dischargeable but non-chargeable mode, thereby discharging the battery pack; or, in the event of an over-discharge fault in the battery pack, control each charging circuit connected to the DC bus to provide a path, control each discharge circuit connected to the DC bus to disconnect, and control each DC / DC circuit connected to the DC bus to be in a chargeable but non-dischargeable mode, thereby charging the battery pack; or, in the event of an over-temperature fault in the battery pack, control each charging circuit and each discharge circuit connected to the DC bus to disconnect, and control each DC / DC circuit connected to the DC bus to be in a standby or shutdown state, thereby bypassing the battery pack.

[0017] This application also provides a control method for an intelligent oil pumping unit system. The intelligent oil pumping unit system includes: N oil pumping units, where N is an integer greater than or equal to 2; the first ends of the N oil pumping units are connected to an AC power source, and the second ends of the N oil pumping units are used to power corresponding motors; the DC buses of the N oil pumping units are connected in parallel; at least one intelligent oil pumping unit is included among the N oil pumping units; the intelligent oil pumping unit includes a rectifier circuit, a frequency converter circuit, a controller, an inverter circuit, a battery pack, and a first protection circuit; the DC side and AC side of the inverter circuit are respectively connected to the DC bus and the AC power source; the two ends of the frequency converter circuit are respectively connected to the DC bus and the corresponding motor; the AC side of the rectifier circuit is connected to the AC power source, and the DC side of the rectifier circuit is connected to the DC bus through the first protection circuit; the DC bus is also used to connect the battery pack; the method includes: during the downstroke of at least one oil pumping unit, controlling the first protection circuit to operate, so that the battery pack stores excess energy from the DC bus.

[0018] As can be seen from the above technical solution, this application has the following beneficial effects: The intelligent oil pumping unit system provided in this application includes N oil pumping units. The first end of each of the N oil pumping units is connected to an AC power source, and the second end of each of the N oil pumping units is used to power the corresponding motors. The DC buses of the N oil pumping units are connected in parallel. At least one of the N oil pumping units is an intelligent oil pumping unit. The intelligent oil pumping unit includes a rectifier circuit, a frequency converter circuit, a controller, an inverter circuit, a battery pack, and a first protection circuit. The rectifier circuit converts the AC power input from the AC power source into DC power to supply the frequency converter circuit, so that the frequency converter circuit can invert the DC power into AC power with an adjustable frequency to drive the motor corresponding to the intelligent oil pumping unit. In order to recover the energy generated by the motor during operation, the controller controls the first protection circuit to work during the downstroke of at least one of the N oil pumping units, so that the battery pack stores the excess energy of the DC bus, effectively realizing energy recovery and reducing the energy consumption of the intelligent oil pumping unit system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an intelligent oil pumping unit system provided in an embodiment of this application; Figure 2 A schematic diagram of another intelligent oil pumping unit system provided in the embodiments of this application; Figure 3 A schematic diagram of a positive electrode protection circuit provided in an embodiment of this application; Figure 4 A schematic diagram of a positive and negative protection circuit provided in an embodiment of this application; Figure 5 A schematic diagram of another positive electrode protection circuit provided in an embodiment of this application; Figure 6This is a schematic diagram of another positive and negative protection circuit provided in an embodiment of this application. Detailed Implementation

[0020] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0021] In this application, the terms "first," "second," etc., are used to distinguish identical or similar items that have essentially the same function. It should be understood that there is no logical or temporal dependency between "first," "second," and "nth," nor does it limit the quantity or order of execution. It should also be understood that although the following description uses the terms "first," "second," etc., to describe various elements, these elements should not be limited by the terms. These terms are merely used to distinguish one element from another.

[0022] See Figure 1 The figure is a schematic diagram of an intelligent oil pumping unit system provided in an embodiment of this application.

[0023] The intelligent oil pumping unit system provided in this application includes N oil pumping units, where N is an integer greater than or equal to 2. This application does not specifically limit the operating state of the N oil pumping units; for example, the N oil pumping units can operate synchronously, i.e., synchronous upstroke or synchronous downstroke; the N oil pumping units can also operate asynchronously.

[0024] The first terminals of N pumping units are connected to AC power supply 10, and the second terminals of the N pumping units are used to power the corresponding motors MN; the DC buses of the N pumping units are connected in parallel; the N pumping units include at least one intelligent pumping unit. For example, the DC buses include a positive DC bus BUS+ and a negative DC bus BUS-, the positive DC buses BUS+ of the N pumping units are connected together, and the negative DC buses BUS- of the N pumping units are connected together.

[0025] For ease of understanding, this application will use an example of an intelligent oil pumping unit system including one intelligent oil pumping unit 100. In this case, the intelligent oil pumping unit system includes N-1 ordinary oil pumping units.

[0026] The intelligent oil pumping unit 100 includes a rectifier circuit 101, a frequency converter circuit 102, a controller 103, an inverter circuit 104, a first protection circuit 105, and a battery pack 106.

[0027] The DC side and AC side of the inverter circuit 104 are connected to the DC bus B100 and the AC power supply 10, respectively. The two ends of the frequency converter circuit 102 are connected to the DC bus B100 and the first motor M1 corresponding to the intelligent oil pumping unit 100, respectively. The AC side of the rectifier circuit 101 is connected to the AC power supply 10, and the DC side of the rectifier circuit 101 is connected to the DC bus B100 through the first protection circuit 105. The DC bus B100 is also used to connect the battery pack 106.

[0028] The embodiments of this application do not specifically limit the type of battery pack 106, but can be specifically set according to actual application needs, such as including lithium battery, sodium battery, solid-state battery or supercapacitor.

[0029] The rectifier circuit 101 converts the AC power input from the AC power source 10 into DC power, providing DC power to the frequency converter circuit 102, the first protection circuit 105, and the battery pack 106. The frequency converter circuit 102 inverts the DC power into AC power with an adjustable frequency to drive the first motor M1.

[0030] The controller 103 is used to control the first protection circuit 105 to operate during the downstroke of at least one of the N pumping units, so that the battery pack 106 stores the excess energy of the DC bus B100.

[0031] The inverter circuit 104 is used to invert the DC power stored in the battery pack 106 into AC power and feed it back to the AC power supply 10.

[0032] The intelligent oil pumping unit system provided in this application includes N oil pumping units. The first end of each of the N oil pumping units is connected to an AC power source, and the second end of each of the N oil pumping units is used to power the corresponding motors. The DC buses of the N oil pumping units are connected in parallel. At least one of the N oil pumping units is an intelligent oil pumping unit. The intelligent oil pumping unit includes a rectifier circuit, a frequency converter circuit, a controller, an inverter circuit, a battery pack, and a first protection circuit. The rectifier circuit converts the AC power input from the AC power source into DC power to supply the frequency converter circuit, so that the frequency converter circuit can invert the DC power into AC power with an adjustable frequency to drive the motor corresponding to the intelligent oil pumping unit. In order to recover the energy generated by the motor during operation, the controller controls the first protection circuit to work during the downstroke of at least one of the N oil pumping units, so that the battery pack stores the excess energy of the DC bus, effectively realizing energy recovery and reducing the energy consumption of the intelligent oil pumping unit system.

[0033] The intelligent oil pumping unit system provided in this application embodiment has a battery pack that can store the regenerative energy generated by the first motor connected to the intelligent oil pumping unit during operation, and can also store the regenerative energy generated by the motor connected to a conventional oil pumping unit during operation.

[0034] See Figure 2The figure is a schematic diagram of another intelligent oil pumping unit system provided in an embodiment of this application.

[0035] In one possible implementation, the intelligent oil pumping unit system provided in this application embodiment includes a second protection circuit 200 in the ordinary oil pumping unit.

[0036] The controller in the intelligent oil pumping unit is used to control the first protection circuit to operate during the downstroke of the intelligent oil pumping unit and at least one ordinary oil pumping unit among N oil pumping units, so that the battery pack stores the regenerative energy generated by the operation of the first motor, or to control the first protection circuit and the second protection circuit 200 in the ordinary oil pumping unit during the downstroke to operate so that the battery pack stores the regenerative energy generated by the motor connected to the first motor and the ordinary oil pumping unit during operation, thereby realizing energy recovery and reducing the energy consumption of the intelligent oil pumping unit system.

[0037] In one possible implementation, the ordinary oil pumping unit in this application embodiment may also include a rectifier circuit and a frequency converter circuit, but this application embodiment does not specifically limit the implementation.

[0038] The circuit topology of the first protection circuit in an intelligent oil pumping unit and the second protection circuit in a conventional oil pumping unit is described in detail below.

[0039] See Figure 3 The figure is a schematic diagram of a positive protection circuit provided in an embodiment of this application.

[0040] In the intelligent oil pumping system provided in this application embodiment, the first protection circuit and the second protection circuit may include a positive protection circuit.

[0041] The positive protection circuit includes a charging circuit 201 and a discharging circuit 202. After the charging circuit 201 is connected to the discharging circuit 202, it is connected to the positive DC bus BUS+. That is, the DC side of the rectifier circuit is connected to the positive DC bus BUS+ through the charging circuit 201 and the discharging circuit 202 in sequence.

[0042] See Figure 4 The figure is a schematic diagram of a positive and negative protection circuit provided in an embodiment of this application.

[0043] In the intelligent oil pumping system provided in this application embodiment, the first protection circuit and the second protection circuit may include positive and negative protection circuits.

[0044] The positive and negative protection circuit includes a charging circuit 201 and a discharging circuit 202. The discharging circuit 202 is connected to the positive DC bus BUS+, and the charging circuit 201 is connected to the negative DC bus BUS-. That is, the DC side of the rectifier circuit is connected to the positive DC bus BUS+ through the discharging circuit 202, and the DC side of the rectifier circuit is connected to the negative DC bus BUS- through the charging circuit 201.

[0045] It should be understood that, Figure 1 and Figure 2 This is just one possible implementation of an intelligent oil pumping unit system, where the first and second protection circuits include positive and negative protection circuits. Figure 1 and Figure 2 These can be changed accordingly, which will not be elaborated here.

[0046] One possible implementation is that the battery pack can store energy during the downstroke of the pumping unit. A controller, in the absence of a battery pack malfunction, controls both the charging circuit 201 and the discharging circuit 202 in the positive protection circuit to provide pathways, or controls both the charging circuit 201 and the discharging circuit 202 in the positive and negative protection circuits to provide pathways, automatically balancing the voltage difference between the battery pack terminal voltage and the pumping unit terminal voltage, so that the battery pack stores excess energy from the DC bus during the downstroke of at least one pumping unit.

[0047] Among them, the non-faulty state of the battery pack can include situations where the battery pack has not experienced overcharge faults, over-discharge faults, or over-temperature faults that would prevent the battery pack from working properly.

[0048] In one possible implementation, the battery pack can also discharge during the upstroke of the pumping unit, providing energy to the pumping unit. Specifically, the controller is used to ensure that both the charging circuit 201 and the discharging circuit 202 in the positive electrode protection circuit are open, or to ensure that both the charging circuit 201 and the discharging circuit 202 in the positive and negative electrode protection circuits are open, based on the automatic balancing of the voltage difference between the battery pack terminal voltage and the pumping unit terminal voltage, so that the battery pack discharges during the upstroke of at least one pumping unit.

[0049] To facilitate understanding, the following section, with reference to the accompanying diagram, describes an implementation method for a charging circuit and a discharging circuit.

[0050] See Figure 5 The figure is a schematic diagram of another positive protection circuit provided in an embodiment of this application.

[0051] In one possible implementation, the positive electrode protection circuit provided in this application embodiment includes a charging circuit 201 comprising a first switch T1 and a first diode D1, and a discharging circuit 202 comprising a second switch T2 and a second diode D2.

[0052] The embodiments of this application do not specifically limit the specific types of the first switch T1 and the second switch T2. For example, they can be insulated gate bipolar transistors (IGBTs) or metal oxide semiconductor field-effect transistors (MOSFETs).

[0053] The first terminal of the first switch T1 is connected to the negative terminal of the first diode D1, and the second terminal of the first switch T1 is connected to the positive terminal of the first diode D1. The first terminal of the second switch T2 is connected to the positive terminal of the second diode D2 and the second terminal of the first switch T1, and the second terminal of the second switch T2 is connected to the negative terminal of the second diode D2. The positive terminal of the second diode D2 is connected to the positive terminal of the first diode D1. The first switch T1 is connected to the second switch T2 and then connected to the positive DC bus BUS+. That is, the DC side of the rectifier circuit is connected to the positive DC bus BUS+ through the first switch T1 and the second switch T2 in sequence.

[0054] See Figure 6 The figure is a schematic diagram of another positive and negative protection circuit provided in an embodiment of this application.

[0055] In one possible implementation, the positive and negative protection circuit provided in this application embodiment includes a charging circuit 201 comprising a first switch T1 and a first diode D1, and a discharging circuit 202 comprising a second switch T2 and a second diode D2.

[0056] The first terminal of the first switch T1 is connected to the negative terminal of the first diode D1, and the second terminal of the first switch T1 is connected to the positive terminal of the first diode D1; the first terminal of the second switch T2 is connected to the negative terminal of the second diode D2, and the second terminal of the second switch T2 is connected to the positive terminal of the second diode D2; the second switch T2 is connected to the positive DC bus BUS+, and the first switch T1 is connected to the negative DC bus BUS-. That is, the DC side of the rectifier circuit is connected to the positive DC bus BUS+ through the second switch T2, and the DC side of the rectifier circuit is connected to the negative DC bus BUS- through the first switch T1.

[0057] The controller is used to control the closing of the first switch T1 in the charging circuit 201 and the second switch T2 in the discharging circuit 202 in the positive protection circuit when the battery pack is not faulty; or to control the closing of the first switch T1 in the charging circuit 201 and the second switch T2 in the discharging circuit 202 in the positive and negative protection circuits, so that the battery pack stores excess energy of the DC bus during the downstroke of at least one pumping unit.

[0058] One possible implementation is that the N pumping units include M intelligent pumping units and NM ordinary pumping units; M is an integer greater than or equal to 1; one of the M intelligent pumping units can be set as the master intelligent pumping unit according to the actual application. For example, one of the M intelligent pumping units can be randomly set as the master intelligent pumping unit. Then, the first protection circuit of the master intelligent pumping unit among the M intelligent pumping units can be a positive protection circuit or a positive and negative protection circuit.

[0059] In the case where the non-crossing voltage difference of the voltage range of at least one of the M-1 intelligent pumping units is less than the voltage difference threshold, that is, when at least one intelligent pumping unit belongs to the same voltage level, when the non-crossing voltage difference between the voltage range of the at least one intelligent pumping unit and the DC bus voltage range of the main intelligent pumping unit is less than the voltage difference threshold, the protection circuit of the at least one intelligent pumping unit can be a positive protection circuit or a positive and negative protection circuit.

[0060] When the non-crossing voltage difference of the voltage range of at least one of the NM ordinary pumping units is less than the voltage difference threshold, that is, when at least one ordinary pumping unit belongs to the same voltage level, the protection circuit of the at least one ordinary pumping unit can be a positive protection circuit or a positive and negative protection circuit when the non-crossing voltage difference between the voltage range of the at least one ordinary pumping unit and the DC bus voltage range of the intelligent pumping unit is less than the voltage difference threshold.

[0061] It should be understood that when M equals 1, that is, when there is only one intelligent pumping unit among the N pumping units, the intelligent pumping unit is equivalent to the main intelligent pumping unit, and the first protection circuit of the intelligent pumping unit can be a positive protection circuit or a positive and negative protection circuit.

[0062] One possible implementation, when M is greater than 1 (i.e., when N pumping units include multiple intelligent pumping units), involves selecting one of the remaining intelligent pumping units as the primary intelligent pumping unit in case the battery pack of the primary intelligent pumping unit fails and bypasses. This can be done based on actual application requirements. For example, multiple intelligent pumping units can be pre-numbered. If the primary intelligent pumping unit needs to be replaced, the intelligent pumping unit with the smallest pre-set number is selected as the primary intelligent pumping unit. In this type of intelligent pumping unit, the controller is the primary controller, used to execute the control actions of the intelligent pumping unit system. The battery pack in this primary intelligent pumping unit is used to store excess energy from the DC bus.

[0063] In one possible implementation, in the intelligent oil pumping unit system provided in this application embodiment, both the first protection circuit and the second protection circuit may include a DC / DC circuit, which is connected to the positive DC bus. That is, the DC side of the rectifier circuit is connected to the positive DC bus through the DC / DC circuit.

[0064] The embodiments of this application do not specifically limit the implementation of DC / DC circuits, and can be specifically set according to actual application requirements, such as including Buck-Boost circuits.

[0065] One possible implementation involves the battery pack storing energy during the downstroke of the pumping unit. During the downstroke, the DC bus voltage of the pumping unit rises, and a controller, in the absence of a battery pack malfunction, controls the operation of the DC / DC circuit, adjusting the input current of the DC / DC circuit so that the battery pack stores excess energy from the DC bus during the downstroke of at least one pumping unit.

[0066] In one possible implementation, the battery pack can also discharge during the upstroke of the pumping unit, providing energy to the pumping unit. Specifically, during the upstroke of the pumping unit, the DC bus voltage of the pumping unit drops, and the controller is used to control the operation of the DC / DC circuit and adjust the output current of the DC / DC circuit so that the battery pack discharges during the upstroke of at least one pumping unit, provided that the battery pack is not faulty.

[0067] One possible implementation, still taking N pumping units including M intelligent pumping units and NM ordinary pumping units as an example, when the non-crossing voltage difference of the voltage range of at least one of the M-1 intelligent pumping units is less than the voltage difference threshold, when the non-crossing voltage difference between the voltage range of the at least one intelligent pumping unit and the DC bus voltage range of the main intelligent pumping unit is greater than or equal to the voltage difference threshold, the protection circuit of the at least one intelligent pumping unit is a DC / DC circuit to achieve the consistency of the voltage connected to the DC bus of the main intelligent pumping unit.

[0068] When the non-crossing voltage difference of the voltage range of at least one of the NM ordinary pumping units is less than the voltage difference threshold, and the non-crossing voltage difference between the voltage range of the at least one ordinary pumping unit and the DC bus voltage range of the intelligent pumping unit is greater than or equal to the voltage difference threshold, the protection circuit of the at least one ordinary pumping unit is a DC / DC circuit to achieve the consistency of the voltage connected to the DC bus of the main intelligent pumping unit.

[0069] The working principle of the intelligent oil pumping unit system is explained below, taking into account the excess energy generated by N pumping units and the total power consumption of N pumping units.

[0070] The intelligent oil pumping unit system provided in this application embodiment, when the excess energy generated by N oil pumping units is greater than the total power consumption of N oil pumping units, and the battery pack is in a fully charged state, the controller is used to control the inverter circuit to work and feed the excess energy of the DC bus back to the AC power supply.

[0071] When the excess energy generated by N pumping units equals the total power consumption of N pumping units, and the battery pack is in a non-discharged state, the controller is used to control the inverter circuit to feed back the energy stored in the battery pack to the AC power supply until the energy of the battery pack is less than or equal to the discharge threshold.

[0072] In this context, a non-discharged state of the battery pack indicates that its state of charge is greater than the discharge threshold and less than the charging threshold, meaning the battery pack has the ability to stably store or feed energy back to the source. Conversely, a discharged state of the battery pack indicates that its state of charge is less than or equal to the discharge threshold, meaning the battery pack no longer has the ability to stably store or feed energy back to the source.

[0073] When the excess energy generated by N pumping units is less than or equal to the total power consumption of N pumping units, the controller is used to control the operation of the rectifier circuit to charge the battery pack using AC power until the energy of the battery pack is greater than or equal to the charging threshold.

[0074] The intelligent oil pumping unit system provided in this application embodiment can control the operation of different circuits in the intelligent oil pumping unit according to the relationship between the excess energy generated by N oil pumping units and the total power consumption, and / or the different states of the battery pack, so as to accurately realize the charging or discharging of the battery pack, maximize the utilization of energy or feedback energy, and improve the energy utilization rate.

[0075] To improve the safety of the intelligent oil pumping unit system, the working principle of the intelligent oil pumping unit system in the event of a battery pack failure is described below.

[0076] In the intelligent oil pumping system provided in this application embodiment, when an overcharge fault occurs in the battery pack, the controller is used to control each discharge circuit connected to the DC bus to provide a path, control each charging circuit connected to the DC bus to disconnect, and control each DC / DC circuit connected to the DC bus to be in a dischargeable and non-chargeable mode, so as to discharge the battery pack.

[0077] In the event of an over-discharge fault in the battery pack, the controller ensures that each charging circuit connected to the DC bus provides a path, each discharging circuit connected to the DC bus is disconnected, and each DC / DC circuit connected to the DC bus is in a rechargeable and non-dischargeable mode, thereby charging the battery pack.

[0078] In the event of an over-temperature fault in the battery pack, the controller is used to disconnect each charging circuit and each discharging circuit connected to the DC bus, and to put each DC / DC circuit connected to the DC bus into standby or shutdown state, thereby bypassing the battery pack.

[0079] The intelligent oil pumping system provided in this application embodiment can accurately control the operation of the first protection circuit and / or the second protection circuit according to the type of battery pack failure when the battery pack fails, so as to reduce the degree of battery pack failure or even eliminate the failure, thereby improving the safety of the battery pack and the safety of the intelligent oil pumping system.

[0080] In practical applications, the counterweight of an oil pumping unit serves as a balancing component. During the upstroke, it moves downwards, releasing gravitational potential energy to assist the motor in its work; during the downstroke, it moves upwards, storing energy for energy recovery. However, existing counterweights are generally unbalanced due to various factors during operation, leading to difficulties in energy recovery.

[0081] Based on this, the intelligent oil pumping system provided in this application embodiment can not only recover energy from the battery pack, but also adjust the balance of the balance block, improve the balance degree of the balance block, and improve the energy storage efficiency of the balance block.

[0082] The intelligent pumping unit system provided in this application embodiment further includes a first balance block; a controller, configured to adjust the first balance block when the first ratio of the upstroke power to the downstroke power of the intelligent pumping unit is less than a first ratio threshold or greater than a second ratio threshold, until the first ratio is greater than the first ratio threshold and less than the second ratio threshold; the first ratio threshold is less than the second ratio threshold, thereby improving the balance of the first balance block of the intelligent pumping unit and thus improving the energy storage efficiency of the first balance block.

[0083] In one possible implementation, the intelligent oil pumping unit system provided in this application embodiment further includes a detection circuit and a second balancing block in a conventional oil pumping unit.

[0084] The detection circuit is used to detect the upstroke power and downstroke power of the corresponding ordinary pumping unit; the controller is used to adjust the second balance block when the second ratio of the upstroke power and downstroke power of the ordinary pumping unit is less than the first ratio threshold or greater than the second ratio threshold, until the second ratio is greater than the first ratio threshold and less than the second ratio threshold, thereby improving the balance of the second balance block of the ordinary pumping unit and thus improving the energy storage efficiency of the second balance block.

[0085] The intelligent pumping unit system provided in this application embodiment has a controller that can determine whether the balance of the balance block meets the requirements based on the upstroke power and downstroke power of the pumping unit. This provides a judgment condition for adjusting the balance of the balance block, thereby improving the balance of the balance block and increasing the energy storage efficiency of the balance block.

[0086] One possible implementation is that the controller can determine the upstroke power of the intelligent pumping unit based on the upstroke current and upstroke voltage; and can determine the downstroke power of the intelligent pumping unit based on the downstroke current and downstroke voltage.

[0087] Similarly, in one possible implementation, the detection circuit can detect the upstroke power of a conventional pumping unit by detecting the upstroke current and upstroke voltage; and it can detect the downstroke power of a conventional pumping unit by detecting the downstroke current and downstroke voltage.

[0088] In the intelligent oil pumping unit system provided in this application embodiment, the controller adjusts the balance block to improve its balance and energy storage efficiency, thereby altering the electrical parameters of the intelligent oil pumping unit. Similarly, to improve the efficiency of the battery pack in storing the regenerative energy of the motor, the controller needs to control the corresponding circuits within the oil pumping unit, which also changes the unit's electrical parameters. Therefore, the intelligent oil pumping unit system provided in this application embodiment, through coordinated control of various circuits within the oil pumping unit, improves the overall efficiency of potential energy storage and motor regenerative energy storage during operation. This enhances both the energy storage efficiency of the battery pack and the energy storage efficiency of the balance block, maximizing energy recovery and reducing the system's energy consumption.

[0089] In light of the above, one possible implementation is that the intelligent oil pumping unit system provided in this application embodiment further includes a donkey head. The battery pack in the intelligent oil pumping unit can be placed at the rear of the unit, with the donkey head close to the head. The positive and negative output terminals of the battery pack can use high-protection power connectors.

[0090] One possible implementation is that the battery pack in the smart pumping unit can be integrated with the first counterweight.

[0091] The intelligent oil pumping unit provided in this application embodiment efficiently utilizes the space of the first balance block to integrate the battery pack and the first balance block together. By utilizing the communication and electrical links of the first balance block, it can realize both the function of the first balance block and the function of charging and discharging the battery pack, thereby improving the integration of the intelligent oil pumping unit and realizing the collaborative work of the first balance block and the battery pack, which can maximize the energy recovery of the intelligent oil pumping unit system.

[0092] In addition, the intelligent oil pump can be equipped with heat dissipation holes in the first balance block. The reciprocating motion of the first balance block, through airflow, can dissipate the heat generated by the battery pack during operation, reducing the battery pack temperature and improving its efficiency. The positive and negative output terminals of the battery pack can utilize concealed, high-protection electrical connectors.

[0093] Based on the intelligent oil pumping unit system described above, this application embodiment also provides a control method for the intelligent oil pumping unit system.

[0094] The control method for the intelligent oil pumping unit system provided in this application embodiment includes: N oil pumping units, where N is an integer greater than or equal to 2; the first end of each of the N oil pumping units is connected to an AC power source, and the second end of each of the N oil pumping units is used to power the corresponding motors; the DC buses of the N oil pumping units are connected in parallel; at least one of the N oil pumping units is an intelligent oil pumping unit; the intelligent oil pumping unit includes a rectifier circuit, a frequency converter circuit, a controller, an inverter circuit, a battery pack, and a first protection circuit; the DC side and AC side of the inverter circuit are respectively connected to the DC bus and the AC power source; the two ends of the frequency converter circuit are respectively connected to the DC bus and the corresponding motor; the AC side of the rectifier circuit is connected to the AC power source, and the DC side of the rectifier circuit is connected to the DC bus through the first protection circuit; the DC bus is also used to connect the battery pack; the control method for the intelligent oil pumping unit system includes: during the downstroke of at least one oil pumping unit, controlling the first protection circuit to operate, so that the battery pack stores excess energy from the DC bus.

[0095] The control method for the intelligent pumping unit system provided in this application embodiment controls the first protection circuit to operate during the downstroke of at least one of the N pumping units, enabling the battery pack to store excess energy from the DC bus, effectively realizing energy recovery and reducing the energy consumption of the intelligent pumping unit system.

[0096] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0097] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An intelligent oil pumping unit system, characterized in that, include: There are N pumping units, where N is an integer greater than or equal to 2. The first end of each of the N pumping units is connected to an AC power source, and the second end of each of the N pumping units is used to power the corresponding motor. The DC buses of the N pumping units are connected in parallel. At least one of the N pumping units is an intelligent pumping unit. The intelligent oil pumping unit includes a rectifier circuit, a frequency converter circuit, a controller, an inverter circuit, a battery pack, and a first protection circuit. The DC side and AC side of the inverter circuit are respectively connected to the DC bus and the AC power supply; the two ends of the frequency converter circuit are respectively connected to the DC bus and the corresponding motor; the AC side of the rectifier circuit is connected to the AC power supply; the DC side of the rectifier circuit is connected to the DC bus through the first protection circuit; the DC bus is also used to connect the battery pack. The controller is used to control the first protection circuit to operate during the downstroke of at least one pumping unit, so that the battery pack stores excess energy from the DC bus.

2. The system according to claim 1, characterized in that, The intelligent oil pumping unit also includes a first counterweight; The controller is configured to adjust the first balance block when the first ratio of the upstroke power to the downstroke power of the intelligent pumping unit is less than a first ratio threshold or greater than a second ratio threshold, until the first ratio is greater than the first ratio threshold and less than the second ratio threshold; wherein the first ratio threshold is less than the second ratio threshold.

3. The system according to claim 2, characterized in that, The intelligent oil pumping unit also includes a donkey head; The battery pack and the first balance block are integrated together; Alternatively, the battery pack is placed at the rear of the intelligent oil pump, with the donkey head close to the head of the intelligent oil pump.

4. The system according to claim 2, characterized in that, The N pumping units include M intelligent pumping units and NM ordinary pumping units; M is an integer greater than or equal to 1; the ordinary pumping units include a detection circuit and a second balancing block; The detection circuit is used to detect the upstroke power and downstroke power of the corresponding ordinary oil pumping unit. The controller is configured to adjust the second balance block when the second ratio of the upstroke power to the downstroke power of the ordinary pumping unit is less than the first ratio threshold or greater than the second ratio threshold, until the second ratio is greater than the first ratio threshold and less than the second ratio threshold.

5. The system according to claim 4, characterized in that, The conventional oil pumping unit also includes a second protection circuit; The first protection circuit and the second protection circuit include a positive protection circuit, or the first protection circuit and the second protection circuit include positive and negative protection circuits; Both the positive electrode protection circuit and the positive and negative electrode protection circuits include a charging circuit, and both the positive electrode protection circuit and the positive and negative electrode protection circuits include a discharging circuit. In the positive protection circuit, the DC side of the rectifier circuit is connected to the positive DC bus in sequence through the charging circuit and the discharging circuit; In the positive and negative protection circuit, the DC side of the rectifier circuit is connected to the positive DC bus through the discharge circuit, and the DC side of the rectifier circuit is connected to the negative DC bus through the charging circuit. The controller is configured to, in the absence of a fault in the battery pack, ensure that both the charging circuit and the discharging circuit provide a path so that the battery pack stores excess energy from the DC bus during the downstroke of at least one pumping unit.

6. The system according to claim 5, characterized in that, The charging circuit includes a first switch and a first diode, with a first terminal of the first switch connected to the negative terminal of the first diode and a second terminal of the first switch connected to the positive terminal of the first diode; the discharging circuit includes a second switch and a second diode. In the positive protection circuit, the first end of the second switch is connected to the positive terminal of the second diode and the second end of the first switch, the second end of the second switch is connected to the negative terminal of the second diode, the positive terminal of the second diode is connected to the positive terminal of the first diode, and the DC side of the rectifier circuit is connected to the positive DC bus through the first switch and the second switch in sequence. In the positive and negative protection circuit, the first end of the second switch is connected to the negative terminal of the second diode, and the second end of the second switch is connected to the positive terminal of the second diode; the DC side of the rectifier circuit is connected to the positive DC bus through the second switch, and the DC side of the rectifier circuit is connected to the negative DC bus through the first switch. The controller is configured to, in the absence of a fault in the battery pack, control the closure of the first switch and the second switch, so that the battery pack stores excess energy from the DC bus during the downstroke of at least one pumping unit.

7. The system according to claim 6, characterized in that, The first protection circuit of the main intelligent pumping unit among the M intelligent pumping units is the positive protection circuit or the positive and negative protection circuit. When the non-crossing voltage difference of the voltage range of at least one of the M-1 intelligent pumping units is less than the voltage difference threshold, and the non-crossing voltage difference between the voltage range of the at least one intelligent pumping unit and the DC bus voltage range of the main intelligent pumping unit is less than the voltage difference threshold, the protection circuit of the at least one intelligent pumping unit is the positive protection circuit or the positive and negative protection circuit. When the non-crossing voltage difference of the voltage range of at least one of the NM ordinary pumping units is less than the voltage difference threshold, and when the non-crossing voltage difference between the voltage range of the at least one ordinary pumping unit and the DC bus voltage range of the intelligent pumping unit is less than the voltage difference threshold, the protection circuit of the at least one ordinary pumping unit is the positive protection circuit or the positive and negative protection circuit.

8. The system according to claim 4, characterized in that, The conventional oil pumping unit also includes a second protection circuit; Both the first protection circuit and the second protection circuit include a DC / DC circuit; the DC side of the rectifier circuit is connected to the positive DC bus through the DC / DC circuit; The controller is used to control the operation of the DC / DC circuit when the battery pack is not faulty, and to adjust the input current of the DC / DC circuit so that the battery pack stores excess energy from the DC bus during the downstroke of at least one pumping unit.

9. The system according to claim 8, characterized in that, When the non-crossing voltage difference of the voltage range of at least one of the M-1 intelligent pumping units is less than the voltage difference threshold, and the non-crossing voltage difference between the voltage range of the at least one intelligent pumping unit and the DC bus voltage range of the main intelligent pumping unit is greater than or equal to the voltage difference threshold, the protection circuit of the at least one intelligent pumping unit is the DC / DC circuit. When the non-crossing voltage difference of the voltage range of at least one of the NM ordinary pumping units is less than the voltage difference threshold, and the non-crossing voltage difference between the voltage range of the at least one ordinary pumping unit and the DC bus voltage range of the intelligent pumping unit is greater than or equal to the voltage difference threshold, the protection circuit of the at least one ordinary pumping unit is the DC / DC circuit.

10. The system according to any one of claims 1 to 9, characterized in that, When the excess energy generated by N pumping units is greater than the total power consumption of N pumping units, and the battery pack is fully charged, the controller is used to control the inverter circuit to feed back the excess energy of the DC bus to the AC power source. Alternatively, if the excess energy generated by N pumping units equals the total power consumption of N pumping units, and the battery pack is in a non-discharged state, the controller is used to control the inverter circuit to feed back the energy stored in the battery pack to the AC power source until the energy of the battery pack is less than or equal to the discharge threshold. Alternatively, if the excess energy generated by the N pumping units is less than or equal to the total power consumption of the N pumping units, the controller is used to control the rectifier circuit to operate and use the AC power supply to charge the battery pack until the energy of the battery pack is greater than or equal to the charging threshold.

11. The system according to claim 10, characterized in that, The controller is configured to, in the event of an overcharge fault in the battery pack, control each discharge circuit connected to the DC bus to provide a path, control each charging circuit connected to the DC bus to disconnect, and control each DC / DC circuit connected to the DC bus to be in a dischargeable and non-chargeable mode, so as to discharge the battery pack. Alternatively, in the event of an over-discharge fault in the battery pack, control each charging circuit connected to the DC bus to provide a path, control each discharging circuit connected to the DC bus to be disconnected, and control each DC / DC circuit connected to the DC bus to be in a rechargeable and non-dischargeable mode, so as to charge the battery pack. Alternatively, in the event of an over-temperature fault in the battery pack, control each charging circuit and each discharging circuit connected to the DC bus to be disconnected, and control each DC / DC circuit connected to the DC bus to be in standby or shutdown state, thereby bypassing the battery pack.

12. A control method for an intelligent oil pumping unit system, characterized in that, The intelligent oil pumping unit system includes: N oil pumping units, where N is an integer greater than or equal to 2; the first end of each of the N oil pumping units is connected to an AC power source, and the second end of each of the N oil pumping units is used to power the corresponding motors; the DC buses of the N oil pumping units are connected in parallel; at least one of the N oil pumping units is an intelligent oil pumping unit; the intelligent oil pumping unit includes a rectifier circuit, a frequency converter circuit, a controller, an inverter circuit, a battery pack, and a first protection circuit; the DC side and AC side of the inverter circuit are respectively connected to the DC bus and the AC power source; the two ends of the frequency converter circuit are respectively connected to the DC bus and the corresponding motor; the AC side of the rectifier circuit is connected to the AC power source, and the DC side of the rectifier circuit is connected to the DC bus via the first protection circuit; the DC bus is also used to connect the battery pack. The method includes: controlling the first protection circuit to operate during the downstroke of at least one pumping unit, so that the battery pack stores excess energy from the DC bus.

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