Variable-frequency power supply device with two-way electric energy balance

Abstract

The invention discloses a double-path electric energy balanced variable frequency power supply device. The double-path electric energy balanced variable frequency power supply device comprises a rectification unit, two inversion units, two direct current circuits, two voltage acquisition units, an energy transfer unit and an electric energy balance control unit. The input end of the rectifying unit is connected to an alternating-current power supply grid; the output ends of the two inversion units are used for being connected to two loads respectively. The two ends of the two direct-current circuits are connected to the output end of the rectifying circuit and the input ends of the two inverter units respectively; the two voltage acquisition units are respectively connected with the two direct-current circuits; two ends of the energy transfer unit are respectively connected with the two direct-current circuits; the electric energy balance control unit is connected with the two voltage acquisition units, the energy transfer channel and the two inversion units. The double-path electric energy balanced variable-frequency power supply device enables the voltages of the two direct-current circuits to tend to be balanced, so that the electric energy of the two loads is in a complementary state, electric energy consumption is reduced, and electric energy accumulation and impact on an alternating-current power supply grid are prevented.

Description

Technical Field

[0001] This application relates to the field of power regulation device technology, and in particular to a frequency converter power supply device with dual-path power balance. Background Art

[0002] During oil extraction, pumping units generate sufficient suction or pressure through reciprocating or rotating motion to extract crude oil from the well and transport it through pipelines to surface storage facilities.

[0003] Currently, 380V AC power is used to drive the load through a frequency converter. This method can solve the problem of current surge during load startup. However, the accumulated electrical energy caused by various factors during the operation of the pumping unit can easily damage the frequency converter. Furthermore, the pumping unit has a relatively high power output, typically around 20kW, resulting in significant energy consumption. To address these issues, some oilfields use a combination of 380V AC power via a frequency converter and capacitor energy storage. This method can solve the problems of electrical energy accumulation and energy consumption, but it involves higher investment and construction costs. Summary of the Invention

[0004] This application provides a frequency converter power supply device with dual-path power balance, which solves the technical problem of high investment and construction costs required when using capacitor energy storage to solve the problems of power accumulation and energy consumption in the prior art.

[0005] This application provides a dual-path power balancing inverter power supply device, comprising: a rectifier unit, the input of which is connected to an AC power grid; two inverter units, the outputs of which are respectively connected to two loads; two DC circuits, the two ends of which are respectively connected to the output of the rectifier circuits and the input of the two inverter units; two voltage acquisition units, each connected to one of the two DC circuits; a power transfer unit, the two ends of which are respectively connected to the two DC circuits, and the power transfer unit having a first-direction power transfer state, a second-direction power transfer state, and an interruption state; and a power balancing control unit, which is connected to the two voltage acquisition units, the power transfer channels, and the two inverter units; and the power balancing control unit is configured to determine the two DC circuits based on the signals from the two voltage acquisition units. The power balance control unit controls the energy transfer unit to be in either the first direction energy transfer state or the second direction energy transfer state when there is a voltage difference between the two DC circuits and the voltage of either DC circuit reaches the upper limit of the balance voltage. When both DC circuits reach the balance voltage, the power balance control unit controls the energy transfer unit to be in the interrupted state. When the balance voltage reaches the balance alarm voltage, the power balance control unit controls the two inverter units to stop working or send an alarm message. When the balance voltage reaches a preset ratio of the balance alarm voltage, the power balance control unit adjusts the output voltage and output frequency of the two inverter units to reduce the balance voltage.

[0006] In one possible implementation, the power balance control unit includes a microcontroller, a power transmission drive module, and a data acquisition module connected to the microcontroller; the data acquisition module is connected to the two voltage acquisition units and configured to receive voltage signals from the two voltage acquisition units and transmit the voltage signals to the microcontroller; the microcontroller is electrically connected to the two inverter units and configured to determine the voltages of the two DC circuits and the balance voltage based on the voltage signals, and control the start / stop, output voltage, and output frequency of the two inverter units based on the balance voltage, and send control signals to the power transmission drive module; the power transmission drive module is electrically connected to the power transmission unit and configured to drive the power transmission unit to change its own state according to the control signals from the microcontroller.

[0007] In one possible implementation, the power balance control unit further includes a Bluetooth module connected to the microcontroller; the Bluetooth module is configured to communicate with an electronic terminal via Bluetooth, transmit voltage data determined by the microcontroller to the electronic terminal, receive control signals from the electronic terminal and transmit them to the microcontroller.

[0008] In one possible implementation, the power balance control unit further includes a remote networking module connected to the microcontroller; the remote networking module is used to connect to a server signal and is configured to transmit the data generated by the microcontroller to the server.

[0009] In one possible implementation, the dual-path power balancing frequency converter further includes: two operating parameter monitoring devices, which are respectively connected to the two loads and configured to monitor the power parameters of the two loads and the attitude parameters of the pumping unit; the power balancing control unit further includes a second data acquisition module, which is connected to the microcontroller and signals connected to the two operating parameter monitoring devices, and is configured to acquire the attitude parameters.

[0010] In one possible implementation, the operating parameter monitoring device includes attitude sensors, two of which are respectively installed on the pumping unit and connected to the second data acquisition module for monitoring the attitude parameters and sending the attitude parameters to the second data acquisition module; wherein, the attitude parameters include the upward stroke, the top running stroke, the downward stroke, and the bottom moving stroke.

[0011] In one possible implementation, the second data acquisition is a LoRa wireless module, which is signal-connected to the two operating parameter monitoring devices.

[0012] In one possible implementation, the power transfer unit includes a thyristor, a first field-effect transistor (FET), and a second FET; the control electrode of the thyristor is connected to the power balance control unit; the gates of the first and second FETs are both connected to the power balance control unit; the source and drain of the first and second FETs are both connected to one of the DC circuits; and the drain of the first and second FETs are connected to the other DC circuit via the thyristor.

[0013] In one possible implementation, the dual-path power balancing frequency converter further includes two energy storage circuits connected to the two DC circuits respectively, for storing the accumulated electrical energy on the two DC circuits.

[0014] In one possible implementation, the energy storage circuit includes a capacitor and a resistor connected in parallel; one end of the capacitor is connected to the DC circuit, and the other end of the capacitor is grounded.

[0015] The technical solutions provided in this application embodiment have at least the following technical effects: This application provides a dual-path power balancing inverter power supply device. When using this device to supply power to two loads, the input terminal of the rectifier unit is connected to the AC power grid. The rectifier unit rectifies the AC power into DC power and outputs it to two DC circuits. Two inverter units invert the DC power from the two DC circuits into AC power and supply it to the two loads. Two voltage acquisition units can respectively acquire the voltage data of the DC circuits and transmit the voltage data to the power balancing control unit. The power balancing control unit can control the state of the power transmission units and adjust the output voltage and frequency of the inverter units according to the voltage data, so that the voltage of the two DC circuits tends to be balanced, thereby achieving a complementary state of power for the two loads, reducing power consumption, and preventing power accumulation and impact on the AC power grid. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the dual-path power balancing frequency converter provided in this application being applied to an oil pumping unit; Figure 2 This is a schematic diagram of the power balance control unit provided in an embodiment of this application; Figure 3 This is a schematic diagram of the energy transfer unit provided in an embodiment of this application.

[0018] Description of reference numerals: 100-Rectifier unit; 200-Inverter unit; 300-DC circuit; 400-Voltage acquisition unit; 500-Energy transfer unit; 510-First field-effect transistor; 520-Second field-effect transistor; 530-SCR; 600-Power balance control unit; 610-Microcontroller; 620-Power transmission drive module; 630-First data acquisition module; 640-Bluetooth module; 650-Remote networking module; 660-Second data acquisition module; 700-Working parameter monitoring device; 800-Energy storage circuit; 810-Capacitor; 820-Resistor; 900-Oil pumping unit; 910-Motor. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In the description of the embodiments of this application, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0021] This application provides an embodiment of a dual-path power balancing frequency converter, such as... Figure 1 As shown, the dual-path power balance inverter power supply device includes a rectifier unit 100, two inverter units 200, two DC circuits 300, two voltage acquisition units 400, a power transmission unit 500, and a power balance control unit 600.

[0022] The input terminal of the rectifier unit 100 is connected to the AC power grid, and the rectifier unit 100 can rectify the AC power from the AC power grid into DC power. For example, the AC power can be 380V AC power, and after the rectification process of the rectifier unit 100, the rectifier unit 100 outputs two 537V DC power.

[0023] The outputs of the two inverter units 200 are respectively connected to two loads. Each inverter unit 200 converts direct current (DC) to alternating current (AC), and provides AC power to the two loads respectively. For example, when this dual-path power balancing inverter power supply is applied to two pumping units, the load is the motor 910 of the pumping unit 900. Figure 1 As shown.

[0024] The two ends of the two DC circuits 300 are respectively connected to the output end of the rectifier circuit and the input end of the two inverter units 200, and are used to transmit the DC power generated by the rectifier unit 100 to the inverter unit 200.

[0025] Two voltage acquisition units 400 are respectively connected to two DC circuits 300 to acquire voltage information from the two DC circuits 300. When the load is the motor 910 of the pumping unit 900, the power of the load will change, and when the pumping unit 900 is performing a downstroke, the motor 910 will generate electricity, which will cause the voltage on the two DC circuits 300 to change; the two voltage acquisition units 400 can acquire the voltage values ​​of the two DC circuits 300 in real time.

[0026] The energy transfer unit 500 is connected to two DC circuits 300 at its two ends, and has a first-direction energy transfer state, a second-direction energy transfer state, and an interruption state. It is used to transfer electrical energy between the two DC circuits 300, bringing them towards equilibrium; where equilibrium means that the voltages of the two DC circuits 300 are equal. Figure 1 As shown in the example, when the energy transfer unit 500 is in the first direction energy transfer state, the electrical energy on the left DC circuit 300 is transferred to the right DC circuit 300; when the energy transfer unit 500 is in the second direction energy transfer state, the electrical energy on the right DC circuit 300 is transferred to the left DC circuit 300; when the energy transfer unit 500 is in the interrupted state, the left DC circuit 300 and the right DC circuit 300 stop the energy transfer process.

[0027] The power balance control unit 600 is connected to two voltage acquisition units 400, the power transmission channel, and two inverter units 200. Furthermore, the power balance control unit 600 is configured to determine the voltages of the two DC circuits 300 and the balance voltage between the two DC circuits 300 based on the signals from the two voltage acquisition units 400; wherein the balance voltage is the voltage value when the voltages of the two DC circuits 300 are equal.

[0028] When there is a voltage difference between the two DC circuits 300 and the voltage of either DC circuit 300 reaches the upper limit of the balance voltage, the power balance control unit 600 controls the energy transfer unit 500 to be in either the first direction energy transfer state or the second direction energy transfer state, so that the power of the DC circuit 300 with the higher voltage is transferred to the DC circuit 300 with the lower voltage; when both DC circuits 300 reach the balance voltage, the power balance control unit 600 controls the energy transfer unit 500 to be in the interrupt state; when the balance voltage reaches the balance alarm voltage, the power balance control unit 600 controls the two inverter units 200 to stop working or send an alarm message; when the balance voltage reaches a preset ratio of the balance alarm voltage, for example, the preset ratio is 80%, the power balance control unit 600 adjusts the output voltage and output frequency of the two inverter units 200 to reduce the balance voltage.

[0029] It should be noted that both the balance upper limit voltage and the balance alarm voltage are preset values ​​in the microcontroller and can be manually adjusted according to the actual situation.

[0030] When using this dual-path power balancing frequency converter to power two loads, the input terminal of the rectifier unit 100 is connected to the AC power grid. The rectifier unit 100 rectifies the AC power into DC power and outputs it to two DC circuits 300. The two inverter units 200 invert the DC power from the two DC circuits 300 into AC power and supply it to the two loads. The two voltage acquisition units 400 can acquire the voltage data of the DC circuits 300 respectively and transmit the voltage data to the power balancing control unit 600. The power balancing control unit 600 determines the balance voltage, balance upper limit voltage, balance alarm voltage, and balance no-load voltage between the two DC circuits 300 based on the voltage of the two DC circuits 300. Based on the voltage data, it controls the state of the power transfer unit 500 and adjusts the output voltage and frequency of the inverter unit 200 so that the voltage of the two DC circuits 300 tends to be balanced. The power of the two loads is complementary, reducing power consumption and preventing power accumulation.

[0031] Figure 1 A schematic diagram is shown illustrating the dual-path power supply system providing power to two pumping units 900. When the motor 910 of the pumping unit 900 rotates, the pumping head of the pumping unit 900 reciprocates up and down. When the pumping head of the pumping unit 900 moves upward, it lifts the sucker rod, drawing crude oil from the well upward, and the motor 910 consumes electrical energy. When the pumping head of the pumping unit moves downward, it drives the motor 910 to generate electricity, causing the voltage on the corresponding DC circuit 300 to rise.

[0032] when Figure 1When the right-hand pumping unit 900 is in the upstroke phase and the left-hand pumping unit 900 is in the downstroke phase, the motor 910 of the right-hand pumping unit 900 consumes electrical energy, while the motor 910 of the left-hand pumping unit 900 generates electrical energy. At this time, there is a voltage difference between the two DC circuits 300. When the voltage in the DC circuit 300 corresponding to the left-hand pumping unit 900 exceeds the upper limit of the balance voltage, some electrical energy in the left-hand DC circuit 300 is transferred to the right-hand DC circuit 300 until the two DC circuits 300 reach a balance voltage. Similarly, when... Figure 1 When the pumping unit 900 on the left is in the upstroke stage and the pumping unit 900 on the right is in the downstroke stage, the motor 910 of the pumping unit 900 on the left consumes electrical energy, and the motor 910 of the pumping unit 900 on the right generates electrical energy. At this time, there is a voltage difference between the two DC circuits 300. When the voltage on the DC circuit 300 corresponding to the pumping unit 900 on the right is greater than the upper limit voltage of the balance, part of the electrical energy of the DC circuit 300 on the right is transferred to the DC circuit 300 on the right until the two DC circuits 300 reach the balance voltage.

[0033] like Figure 2 As shown in this embodiment, the power balance control unit 600 includes a microcontroller 610, a power transmission drive module 620, and a first data acquisition module 630 connected to the microcontroller 610. The first data acquisition module 630 is connected to two voltage acquisition units 400 and configured to receive voltage signals from the two voltage acquisition units 400 and transmit the voltage signals to the microcontroller 610. The microcontroller 610 is electrically connected to two inverter units 200 and configured to determine the voltage and balance voltage of the two DC circuits 300 based on the voltage signals, control the start / stop, output voltage, and output frequency of the two inverter units 200 based on the balance voltage, and send control signals to the power transmission drive module 620. The power transmission drive module 620 is electrically connected to the power transmission unit 500 and configured to drive the power transmission unit 500 to change its own state according to the control signals from the microcontroller 610.

[0034] When the microcontroller 610 determines, based on the voltage signals acquired by the two voltage acquisition units 400, that the voltage of the left DC circuit 300 is greater than the voltage of the right DC circuit 300, the microcontroller 610 sends a control signal to the power transmission drive module 620. This control signal instructs the power transmission drive module 620 to control the drive power transmission unit 500 to switch to the first direction power transmission state. Correspondingly, when the microcontroller 610 determines, based on the voltage signals acquired by the two voltage acquisition units 400, that the voltage of the right DC circuit 300 is greater than the voltage of the left DC circuit 300, the microcontroller 610 sends a control signal to the power transmission drive module 620. This control signal instructs the power transmission drive module 620 to control the drive power transmission unit 500 to switch to the second direction power transmission state.

[0035] When the balance voltage reaches the balance alarm voltage, the microcontroller 610 controls the two inverter units 200 to stop working or send an alarm signal; when the balance voltage reaches the preset ratio of the balance alarm voltage, the microcontroller 610 controls the output voltage and output frequency of the two inverter units 200 to reduce the balance voltage between the two DC circuits 300.

[0036] Continue to refer to Figure 2 The power balance control unit 600 also includes a Bluetooth module 640 connected to the microcontroller 610. The Bluetooth module 640 is used to communicate with an electronic terminal via Bluetooth and is configured to transmit voltage data determined by the microcontroller 610 and the status of the power transmission unit 500 to the electronic terminal, and to receive control signals from the electronic terminal and transmit them to the microcontroller 610.

[0037] The microcontroller 610 establishes communication with the electronic terminal via the Bluetooth module 640. Oilfield maintenance personnel can view voltage data and the status of the power transmission unit 500 through the electronic terminal. Furthermore, maintenance personnel can use the electronic terminal to send control signals to the microcontroller 610. The Bluetooth module 640 of the power balance control unit 600 receives the control signals and forwards them to the microcontroller 610. The electronic terminal can be a mobile phone, tablet, laptop, or other device capable of Bluetooth communication.

[0038] Furthermore, the power balance control unit 600 also includes a remote networking module 650 connected to the microcontroller 610. The remote networking module 650 is used to connect to a server and is configured to transmit data generated by the microcontroller 610 to the server. This server can be an existing data center in the oilfield, a standalone server, or a server that communicates with and is connected to an existing data center in the oilfield.

[0039] Oilfield maintenance personnel can use a monitoring platform connected to the server to monitor the system in real time. This helps to identify and resolve problems promptly, improving the reliability and efficiency of the dual-path power balancing frequency converter. Furthermore, the remote networking module 650 can receive instructions from the server, allowing oilfield maintenance personnel to remotely adjust the settings of the power balancing control unit 600 and send control commands to the microcontroller 610.

[0040] Furthermore, such as Figure 1 As shown, the dual-path power balance inverter power supply device provided in this application embodiment also includes two operating parameter monitoring devices 700. The two operating parameter monitoring devices 700 are respectively connected to two loads and electrically connected to the power balance control unit 600, and are configured to monitor the power parameters of the two loads and the attitude parameters of the pumping unit 900.

[0041] The power balance control unit 600 also includes a second data acquisition module 660. The second data acquisition module 660 is connected to the microcontroller 610 and signal-connected to two operating parameter monitoring devices 700. It is configured to acquire the power parameters of the two loads and the attitude parameters of the pumping unit 900, and transmit the attitude parameters to the microcontroller 610. The microcontroller 610 can determine the cause of voltage changes in the two DC circuits 300 based on the parameters acquired by the two operating parameter monitoring devices 700. This data can serve as the basis for the microcontroller 610 to balance the power on the two DC circuits 300 via the power transfer drive module 620.

[0042] Specifically, the working parameter monitoring device 700 in this embodiment includes attitude sensors. Two attitude sensors are respectively installed on the pumping unit 900 and connected to the second data acquisition module 660 for monitoring attitude parameters and sending the attitude parameters to the second data acquisition module 660. The attitude parameters include the upward stroke, the top running stroke, the downward stroke, and the bottom moving stroke.

[0043] Specifically, the second data acquisition module 660 is a LoRa wireless module. The two operating parameter monitoring devices 700 transmit attitude parameters to the second data acquisition module 660 wirelessly. The LoRa wireless module is connected to the two operating parameter monitoring devices via signal.

[0044] Of course, in some other embodiments of this application, the second data acquisition module 660 may also be a narrowband Internet of Things (NB-IoT) module.

[0045] like Figure 3 As shown in this embodiment, the power transfer unit 500 includes a silicon controlled rectifier (SCR) 530, a first field-effect transistor (FET) 510, and a second FET 520. The control electrode of the SCR 530 is connected to the power balance control unit 600; the gates of the first FET 510 and the second FET 520 are both connected to the power balance control unit 600; the source of the first FET 510 and the drain of the second FET 520 are both connected to one of the DC circuits 300; and the drain of the first FET 510 and the source of the second FET 520 are connected to another DC circuit 300 via the SCR 530.

[0046] When the energy transfer unit 500 is in the first direction energy transfer state, the power balance control unit 600 connects the thyristor 530 through its control electrode, controls the source and drain of the first field-effect transistor 510 to be connected through its gate, and controls the source and drain of the second field-effect transistor 520 to be disconnected through its gate. When the energy transfer unit 500 is in the second direction energy transfer state, the power balance control unit 600 connects the thyristor 530 through its control electrode, controls the source and drain of the second field-effect transistor 520 to be connected through its gate, and controls the source and drain of the first field-effect transistor 510 to be disconnected through its gate. When the power transfer unit 500 is in an interrupted state, the power balance control unit 600 disconnects the thyristor 530 through the control electrode of the thyristor 530.

[0047] like Figure 1 As shown, the dual-path power balancing frequency converter provided in this application embodiment further includes two energy storage circuits 800 respectively connected to two DC circuits 300, and the two energy storage circuits 800 are used to store the accumulated electrical energy on the two DC circuits 300.

[0048] When there is accumulated electrical energy in the DC circuit 300, the accumulated electrical energy is stored in the energy storage circuit 800, thereby preventing the accumulated electrical energy from damaging the electronic devices in the rectifier unit 100 and the inverter unit 200.

[0049] Specifically, the energy storage circuit 800 includes a capacitor 810 and a resistor 820 connected in parallel. One end of the capacitor 810 is connected to the DC circuit 300, and the other end of the capacitor 810 is grounded. In this energy storage circuit 800, the capacitor is used to store electrical energy. When the circuit is on, the power supply charges the capacitor through the resistor 820; when the circuit is off, the capacitor discharges through the resistor 820.

[0050] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0051] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A variable frequency power supply device with dual-circuit power balance, characterized in that: include: A rectifier unit, wherein an input end of the rectifier unit is connected to an AC power supply grid; Two inverter units, wherein output ends of the two inverter units are used to be connected to two loads respectively; Two DC circuits, two ends of which are connected to the output end of the rectifier circuit and the input ends of the two inverter units respectively; Two voltage collection units, the two voltage collection units are respectively connected to the two DC circuits; An energy transmission unit, wherein two ends of the energy transmission unit are respectively connected to the two DC circuits, and the energy transmission unit has a first direction energy transmission state, a second direction energy transmission state and an interruption state; as well as An electric energy balance control unit, the electric energy balance control unit is connected to the two voltage acquisition units, the energy transfer channel and the two inverter units; and the electric energy balance control unit is configured to determine the voltages of the two DC circuits and the balance voltage between the two DC circuits according to the signals of the two voltage acquisition units; wherein the balance voltage is a voltage value when the voltages of the two DC circuits are equal; When there is a voltage difference between the two DC circuits and the voltage of any one of the DC circuits reaches the upper limit voltage of balance, the power balance control unit controls the energy transfer unit to be in the first direction energy transfer state or the second direction energy transfer state, so that the power of the DC circuit with higher voltage is transferred to the DC circuit with lower voltage; when both DC circuits reach the balance voltage, the power balance control unit controls the energy transfer unit to be in the interruption state; When the balancing voltage reaches the balancing alarm voltage, the power balancing control unit controls the two inverter units to stop working or send an alarm message to the outside; when the balancing voltage reaches a preset proportion of the balancing alarm voltage, the power balancing control unit adjusts the output voltage and output frequency of the two inverter units to reduce the balancing voltage.

2. The variable frequency power supply device with dual-circuit power balance according to claim 1, characterized in that: The power balance control unit includes a microcontroller, and a power transmission drive module and a first data acquisition module connected to the microcontroller; The first data acquisition module is connected to the two voltage acquisition units and is configured to receive voltage signals from the two voltage acquisition units and transmit the voltage signals to the microcontroller; The microcontroller is electrically connected to the two inverter units, and is configured to determine the voltages of the two DC circuits and the balance voltage according to the voltage signal, and to control the start and stop, output voltage and output frequency of the two inverter units according to the balance voltage, and to send a control signal to the power transmission drive module; The power transmission drive module is electrically connected to the power transmission unit, and is configured to drive the power transmission unit to change its state according to the control signal of the microcontroller.

3. The variable frequency power supply device with dual-circuit power balance according to claim 2, characterized in that: The power balance control unit also includes a Bluetooth module connected to the microcontroller; The Bluetooth module is used to communicate with the electronic terminal via Bluetooth, and is configured to transmit the voltage data determined by the microcontroller to the electronic terminal, receive the control signal from the electronic terminal and transmit it to the microcontroller.

4. The variable frequency power supply device with dual-circuit power balance according to claim 2 or 3, characterized in that: The power balance control unit also includes a remote networking module connected to the microcontroller; The remote networking module is used for signal connection with a server and is configured to transmit the data generated by the microcontroller to the server.

5. The variable frequency power supply device with dual-circuit power balance according to claim 4, characterized in that: Also includes: [1] The two working parameter monitoring devices are used to be connected to the two loads respectively, and are configured to monitor the power parameters of the two loads and the posture parameters of the pumping unit; The power balance control unit also includes a second data acquisition module, which is connected to the microcontroller and has signal connection to the two working parameter monitoring devices, and is configured to obtain the posture parameters.

6. The variable frequency power supply device with dual-circuit power balance according to claim 5, characterized in that: The working parameter monitoring device includes a posture sensor, two of which are respectively installed on the oil pumping units and connected to the second data acquisition module, for monitoring the posture parameters and sending the posture parameters to the second data acquisition module; wherein the posture parameters include an upward stroke, a top running stroke, a downward stroke and a bottom movement stroke.

7. The variable frequency power supply device with dual-circuit power balance according to claim 5, characterized in that: The second data acquisition is a LORA wireless module, and the LORA wireless module is signal-connected to the two working parameter monitoring devices.

8. The variable frequency power supply device with dual-circuit power balance according to claim 1, characterized in that: The energy transmission unit includes a thyristor, a first field effect transistor and a second field effect transistor; The control electrode of the thyristor is connected to the power balance control unit; The gate of the first field effect transistor and the gate of the second field effect transistor are both connected to the power balance control unit, the source of the first field effect transistor and the drain of the second field effect transistor are both connected to one of the DC circuits, and the drain of the first field effect transistor and the source of the second field effect transistor are connected to the other DC circuit through the thyristor.

9. The variable frequency power supply device with dual-circuit power balance according to claim 1, characterized in that: Also includes: Two energy storage circuits are respectively connected to the two DC circuits and are used to store the accumulated electric energy on the two DC circuits.

10. The variable frequency power supply device with dual-circuit power balance according to claim 9, characterized in that: The energy storage circuit includes a capacitor and a resistor arranged in parallel; One end of the capacitor is connected to the DC circuit, and the other end of the capacitor is grounded.

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