Multi-machine transmission intelligent frequency conversion integrated device for micro-grid of oil production well field

Abstract

A micro-grid multi-machine transmission intelligent frequency conversion integrated device for an oil production well site belongs to the technical field of oil field well site energy supply and equipment transmission control, and is characterized by comprising an integrated cabinet body, a photovoltaic energy storage system, a multi-machine transmission system and a well site intelligent control system are arranged in the integrated cabinet body; the photovoltaic energy storage system is respectively communicated with the multi-machine transmission system and the well site intelligent control system; and the multi-machine transmission system is communicated with the well site intelligent control system. All core systems are integrated through the container type cabinet body, the layout is integrated and simplified, the occupied area is reduced by 60%, the installation and debugging period is shortened by 30%, and the construction cost is reduced; the photovoltaic direct current is directly connected to the direct current bus for direct driving of the pumping unit, and the absorption rate is increased to 90% or above; the matched energy storage battery is used for storing redundant electric energy, so that the photovoltaic consumption rate can be effectively improved, near-zero-carbon operation is realized, and near-zero-carbon well site construction requirements are met; continuous production during failure is ensured through power frequency loop backup, failure loss is reduced, and multiple safety guarantees are achieved.

Description

A multi-machine drive intelligent frequency conversion integrated device for microgrids in oil well sites Technical Field

[0001] This invention belongs to the field of energy supply and equipment transmission control technology in oilfield well sites, and particularly relates to an intelligent frequency conversion integrated device for multi-machine transmission in microgrids of oilfield well sites. Background Technology

[0002] During oil extraction, well sites need to continuously supply power to multiple pumping units. Currently, traditional well sites suffer from technical defects such as low energy utilization efficiency, high dependence on mains power, dispersed equipment with poor coordination, and insufficient operational safety.

[0003] The low energy efficiency is manifested in several ways: While some well sites are equipped with distributed photovoltaic systems, the photovoltaic DC power needs to be converted from AC / DC to AC before being supplied to the pumping units, resulting in significant energy loss and a terminal absorption rate of less than 60%. Furthermore, multiple pumping units are equipped with independent drive systems, lacking an energy feedback mechanism, leading to direct waste of braking energy and high energy consumption. High dependence on grid power is also evident: Well sites have high daily power consumption (e.g., 5 11kW pumping units require ≥300kWh daily), and photovoltaic power supply only covers a portion of the time, with the remaining time entirely reliant on grid power, making near-zero carbon operation difficult. Dispersed equipment and poor coordination are further problematic: Existing distribution cabinets, CNC cabinets, and main control cabinets at well sites are scattered, requiring separate wiring and debugging, resulting in large floor space requirements. Each system (power supply, drive, monitoring) operates independently, making it impossible to dynamically adjust power supply strategies based on photovoltaic output and energy storage status, leading to poor control flexibility. The lack of operational safety is specifically manifested in the following ways: lack of real-time monitoring of cable joint temperature and energy storage battery status, resulting in delayed fault warnings; no emergency power backup, leading to production losses due to pumping unit shutdown when mains power is interrupted or frequency converter system fails. Summary of the Invention

[0004] The present invention aims to solve the above problems by providing an integrated, collaborative, and intelligent multi-machine drive intelligent frequency conversion integrated device for oil well site microgrids, so as to improve the photovoltaic absorption rate, reduce the dependence on mains power, simplify equipment layout and ensure operational safety.

[0005] The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site, as described in this invention, includes an integrated cabinet. The integrated cabinet contains an energy storage compartment, a multi-machine drive compartment, and a control and display compartment. The integrated cabinet also houses a photovoltaic energy storage system, a multi-machine drive system, and a well site intelligent control system. The photovoltaic energy storage system is located in the energy storage compartment. The multi-machine drive system is located in the multi-machine drive compartment. The well site intelligent control system is located in the control and display compartment. The photovoltaic energy storage system is connected to both the multi-machine drive system and the well site intelligent control system. The multi-machine drive system is also connected to the well site intelligent control system.

[0006] Each compartment transmits power to the busbar via internal cables and exchanges control signals via internal signal cables.

[0007] Furthermore, in the oil well site microgrid multi-machine drive intelligent frequency conversion integrated device of the present invention, the photovoltaic energy storage system includes a photovoltaic controller, a DC-DC converter, a battery management system, an inverter grid-connected system, and an energy storage battery; the photovoltaic controller is connected to the energy storage battery and the inverter grid-connected system respectively; the energy storage battery is connected to the battery management system and the DC-DC converter respectively; and the battery management system is connected to the DC-DC converter.

[0008] The input terminal of the photovoltaic controller is connected to the distributed photovoltaic module at the well site, and the output terminal is connected in two ways: one is connected to the energy storage battery, and the other is connected to the public power grid after passing through the inverter grid connection system; the electrical energy of the energy storage battery is converted into DC voltage by the DC-DC converter and then connected to the common DC bus.

[0009] Furthermore, the intelligent frequency conversion integrated device for multi-machine drive in the microgrid of the oil well site described in this invention includes a multi-machine drive system comprising a common DC bus unit, a rectifier unit, an inverter unit, and a backup power frequency circuit unit; the rectifier unit, the common DC bus unit, and the inverter unit are sequentially connected to form a frequency conversion circuit; the rectifier unit is externally connected to the public power grid; the common DC bus unit is connected to the aforementioned DC-DC converter; both the inverter unit and the backup power frequency circuit unit include several groups; the output end of the inverter unit is externally connected to the pumping unit to supply power to the pumping unit.

[0010] The rectifier unit supports multiple sets of parallel operation, with its input end connected to the public power grid and its output end connected to the common DC bus; the input ends of the inverter units are all connected to the common DC bus, and their output ends are respectively connected to one pumping unit drive motor; the backup power frequency circuit unit is connected in parallel with the output end of the inverter unit for emergency power supply of the pumping unit.

[0011] Furthermore, the intelligent frequency conversion integrated device for multi-machine drive in the microgrid of the oil well site described in this invention includes an edge computing gateway, an industrial switch, an outdoor WiFi AP, an embedded touch screen, a power monitoring module, and a safety monitoring module. The power monitoring module includes a smart meter and supporting sensors. The industrial switch, outdoor WiFi AP, embedded touch screen, power monitoring module, and safety monitoring module are all connected to the edge computing gateway. The industrial switch is connected to the outdoor WiFi AP. The edge computing gateway is connected to the aforementioned photovoltaic controller, battery management system, DC-DC converter, and inverter grid-connected system. The edge computing gateway is also connected to the aforementioned rectifier unit and inverter unit.

[0012] The smart meter and supporting sensors of the power monitoring module are respectively installed at the input end of the public power grid, the output end of the photovoltaic module, and the output end of the energy storage battery to collect voltage, current, power, and energy data; the edge computing gateway receives the operating data of the power monitoring module and the pumping unit and generates power consumption optimization scheduling strategies; the WiFi outdoor AP is used to realize wireless data transmission between wellhead cabinets, between valve group protocol boxes and integrated cabinets.

[0013] Furthermore, the intelligent frequency conversion integrated device for multi-machine drive in the microgrid of the oil well site described in this invention includes an inverter unit comprising a DC circuit breaker, a buffer, an inverter, a first AC contactor, and an output terminal block connected in sequence; the DC circuit breaker is connected to a common DC bus unit; and the output terminal block is externally connected to the pumping unit via a power supply cable. A DC circuit breaker and a buffer are provided between the inverter and the common DC bus unit. When a single oil well pumping unit malfunctions or requires maintenance, disconnecting the DC circuit breaker in the corresponding inverter unit achieves power outage for that single oil well without needing to disconnect the main circuit breaker, thus not affecting the normal production of other oil wells.

[0014] Furthermore, in the intelligent frequency conversion integrated device for multi-machine drive in the microgrid of the oil well site described in this invention, the backup power frequency circuit unit includes an AC circuit breaker, a second AC contactor, and a thermal relay connected in sequence; the output terminal of the thermal relay is connected to the output terminal block of the aforementioned inverter unit. When an abnormality occurs in the frequency conversion circuit, the edge computing gateway in the well site intelligent control system monitors the operating status of the frequency conversion circuit in real time. Upon detecting an abnormality, it automatically switches the power supply system to the power frequency circuit, ensuring uninterrupted power supply to the pumping unit for production.

[0015] Furthermore, the intelligent frequency conversion integrated device for multi-machine drive in the microgrid of the oil well site described in this invention includes a safety monitoring module comprising a patch-type temperature sensor, a cabinet temperature and humidity sensor, and a voice alarm unit. Patches-type temperature sensors are installed on the DC-DC converter, the public power grid, the common DC bus unit, and the inverter unit; cabinet temperature and humidity sensors are installed in the energy storage compartment, the multi-machine drive compartment, and the control and display compartment; the voice alarm unit is located on the top of the cabinet. When the cable joint temperature exceeds a threshold, the temperature and humidity inside the cabinet are abnormal, or an abnormal intrusion is detected, the voice alarm unit can trigger an alarm and simultaneously cut off the corresponding power supply circuit.

[0016] Furthermore, in the integrated intelligent frequency conversion device for multi-machine drive in the microgrid of the oil well site described in this invention, the control and display compartment is provided with a secondary door; the secondary door opening is fitted with an embedded touch screen.

[0017] Furthermore, in the oil well site microgrid multi-machine drive intelligent frequency conversion integrated device of the present invention, the photovoltaic controller is externally connected to the well site distributed photovoltaic modules; the inverter grid-connected system, rectifier unit and backup power frequency circuit unit are all connected to the public power grid; the inverter unit and backup power frequency circuit unit are both connected to the well site pumping unit motor.

[0018] The battery management system monitors the voltage, current, temperature, and remaining capacity of the energy storage battery in real time, and controls the charging and discharging process of the energy storage battery. When the real-time power generation of the external photovoltaic module is greater than the sum of the charging power of the energy storage battery and the load power of the pumping unit, it automatically switches to the inverter grid-connected system to invert the photovoltaic DC power into AC power and connect it to the public power grid. The power monitoring module collects voltage, current, power, and energy data from the input end of the public power grid, the output end of the photovoltaic module, the output end of the energy storage battery, and the pumping unit at the well site, and transmits them to the edge computing gateway via an industrial switch. The edge computing gateway analyzes the data to generate power optimization strategies. When the photovoltaic power is greater than the load power, it controls the energy storage battery to charge; when the photovoltaic power is less than the load power, it controls the energy storage battery to discharge; and when the public power grid is interrupted, it triggers emergency power supply from the energy storage.

[0019] The patch-type temperature sensor monitors the temperature of the cable joints in the aforementioned DC-DC converter, public power grid, common DC bus unit, and inverter unit; the cabinet temperature and humidity sensor monitors environmental parameters; and triggers a voice alarm and cuts off the corresponding circuit when an abnormality occurs.

[0020] Furthermore, in the oil well site microgrid multi-machine drive intelligent frequency conversion integrated device of the present invention, the braking energy of the well site pumping unit is fed back to the common DC bus through the inverter unit, realizing the mutual feedback utilization of energy.

[0021] The intelligent frequency conversion integrated device for multi-machine drive in the microgrid of the oil well site described in this invention integrates all core systems through a containerized cabinet, simplifying the layout and reducing the footprint by 60%, shortening the installation and commissioning cycle by 30%, and reducing construction costs. Photovoltaic DC power is directly connected to the DC bus to power the pumping units, increasing the absorption rate to over 90%. The supporting energy storage battery stores excess energy, allowing operation without mains power when there is sufficient sunlight, and supplementing with mains power during continuous cloudy or rainy periods, effectively improving the photovoltaic absorption rate and achieving near-zero carbon operation, meeting the requirements for near-zero carbon well site construction. The common DC bus design enables the recovery of braking energy from multiple pumping units, reducing energy consumption by 15%-20% and reducing energy waste. The edge computing gateway dynamically optimizes the power supply strategy, and the WiFi network supports wireless control, enabling intelligent regulation and remote management. The power frequency circuit backup ensures continuous production in case of failure, and the safety monitoring module monitors temperature and environment in real time, alarming and cutting off the circuit in case of anomalies, reducing failure losses and achieving multiple safety guarantees. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the integrated cabinet structure according to an embodiment of the present invention; Figure 2 is a system architecture diagram of the integrated device according to an embodiment of the present invention; Figure 3 is a topology diagram of the well site power operation according to an embodiment of the present invention; Figure 4 is an electrical structure diagram of the multi-machine transmission system according to an embodiment of the present invention; Figure 5 is a connection diagram of the intelligent control system according to an embodiment of the present invention; Figure 6 is a connection diagram of the field equipment according to an embodiment of the present invention. Detailed Implementation

[0023] The following detailed description of the intelligent frequency conversion integrated device for multi-machine drive in oil well site microgrids according to the present invention is provided with reference to the accompanying drawings and embodiments.

[0024] This embodiment discloses an integrated intelligent frequency conversion device for multi-machine drive in an oil well site microgrid, including a containerized integrated cabinet and a photovoltaic energy storage system, a multi-machine drive system, and an intelligent control system for the well site integrated within the cabinet.

[0025] As shown in Figure 1, the integrated cabinet in this embodiment measures 3600mm × 1800mm × 1000mm and is divided into three functional compartments: Energy Storage Compartment: used to assemble 50-500kWh lithium iron phosphate batteries. The charging and discharging cables of the energy storage batteries are connected to the common DC bus of the multi-machine drive compartment through the internal terminal block. The control signals are connected to the well site intelligent control system through the signal cable; Multi-machine Drive Compartment: has a public power grid access hole (380V AC) and a pumping unit load output hole (380VAC) at the bottom. It is equipped with a rectifier unit, a common DC bus, a buffer unit, an inverter unit, a DC circuit breaker, an AC circuit breaker, and backup power frequency components; Control and Display Compartment: equipped with a mounting base plate and a secondary door. The secondary door opening is fitted with an embedded touch screen, operation buttons, and indicator lights. It is equipped with an edge computing gateway, an industrial switch, a WiFi outdoor AP, and a power monitoring module.

[0026] In this embodiment of the present disclosure, as shown in FIG2, the photovoltaic energy storage system includes a photovoltaic controller, a DC-DC converter, a battery management system, an inverter grid-connected system, and an energy storage battery; the photovoltaic controller is connected to the energy storage battery and the inverter grid-connected system respectively; the energy storage battery is connected to the battery management system and the DC-DC converter respectively; the battery management system is connected to the DC-DC converter.

[0027] The multi-machine drive system includes a common DC bus unit, a rectifier unit, an inverter unit, and a backup power frequency circuit unit. The rectifier unit, common DC bus unit, and inverter unit are connected in sequence to form a frequency conversion circuit. The backup power frequency circuit unit is connected to the inverter unit. The rectifier unit is connected to the public power grid via a main AC circuit breaker. The common DC bus unit is connected to the aforementioned DC-DC converter via a DC circuit breaker. Both the inverter unit and the backup power frequency circuit unit include several groups of the same number. The output end of the inverter unit is connected to an external oil pumping unit.

[0028] The inverter unit includes a DC circuit breaker, a buffer, an inverter, a first AC contactor, and an output terminal block connected in sequence; the DC circuit breaker is connected to the common DC bus unit; the output terminal block is connected to the oil pumping unit via a power supply cable.

[0029] The backup power frequency circuit unit includes an AC circuit breaker, a second AC contactor, and a thermal relay connected in sequence; the output terminal of the thermal relay is connected to the output terminal block of the aforementioned inverter unit.

[0030] The intelligent control system for the well site includes an edge computing gateway, an industrial switch, an outdoor WiFi access point (AP), an embedded touchscreen, a power monitoring module, and a safety monitoring module. The power monitoring module includes a smart meter and associated sensors. The safety monitoring module includes a surface-mount temperature sensor, an internal temperature and humidity sensor, and a voice alarm unit. In this embodiment, surface-mount temperature sensors are installed on the cable connectors at the output end of the DC-DC converter, the input end of the public power grid, the common DC bus unit, and the output end of the inverter unit. Internal temperature and humidity sensors are installed in the energy storage compartment, the multi-machine drive compartment, and the control display compartment. The voice alarm unit is located on the top of the cabinet. The industrial switch, outdoor WiFi AP, embedded touchscreen, power monitoring module, and safety monitoring module are all connected to the edge computing gateway. The industrial switch is connected to the outdoor WiFi AP. The edge computing gateway is connected to the aforementioned photovoltaic controller, battery management system, DC-DC converter, and inverter grid-connected system. The edge computing gateway is also connected to the aforementioned rectifier unit and inverter unit.

[0031] In this embodiment, the photovoltaic controller is externally connected to distributed photovoltaic modules at the well site; the inverter grid-connected system, rectifier unit, and backup power frequency circuit unit are all connected to the public power grid; the inverter unit and backup power frequency circuit unit are both connected to the well site pumping unit. The braking energy of the well site pumping unit is fed back to the common DC bus via the inverter unit, realizing mutual energy feedback utilization.

[0032] In this embodiment, when the integrated device is running, the distributed photovoltaic modules at the well site output DC power to the photovoltaic controller. The photovoltaic controller outputs power in two ways: one way connects to the inverter grid-connected system (to achieve grid connection of photovoltaic power), and the other way connects to the energy storage battery and is connected to the common DC bus via a DC / DC converter, realizing bidirectional power conversion (charging / discharging) between the energy storage battery and the DC bus. The photovoltaic controller, BMS battery management system, and DC / DC converter interact via cables: the BMS battery management system monitors the charging and discharging status and health of the energy storage battery in real time.

[0033] The public power grid outputs 380V AC power to the rectifier unit, which converts the AC power into DC power and connects it to the common DC bus. The common DC bus is the core power hub, which connects to multiple inverter units. The multiple inverter units convert the DC power into AC power to drive the pumping unit motor.

[0034] The public power grid outputs 380V AC power to the backup power frequency circuit unit to provide emergency power frequency power to the pumping unit motor (activated when the frequency converter system fails).

[0035] The edge computing gateway serves as the core control node of the integrated device, connecting to an industrial switch, embedded touchscreen, power monitoring module, security monitoring module, and outdoor WiFi access point (AP). The power monitoring module collects voltage / current / power data from the public power grid, photovoltaic system, energy storage battery, and pumping unit circuit. The security monitoring module monitors safety parameters such as equipment temperature, insulation, and abnormal intrusion. The outdoor WiFi AP wirelessly connects to the pumping unit's data acquisition and monitoring system, which monitors the pumping unit motor's operating data (load, displacement, electrical parameters, etc.) in real time and feeds it back to the intelligent control system. Simultaneously, the edge computing gateway interacts with the photovoltaic energy storage system and multi-machine drive system via signal cables, enabling intelligent closed-loop management of energy dispatching, equipment control, and status monitoring.

[0036] When the integrated intelligent frequency conversion device for multi-machine drive in the microgrid of the oil well site described in this embodiment is implemented at the well site, the power operation topology of the well site is shown in Figure 3.

[0037] The photovoltaic (PV) modules output DC 300-800V, which is connected to the PV controller. The controller adjusts the voltage to DC 500-600V and outputs it in two ways: one way connects to the DC bus via a DC / DC converter with the energy storage battery, enabling the PV power to be consumed at the end of the grid. The other way connects to the inverter grid-connected system, where it is converted to 380V AC and then fed into the public grid. When the power cannot be fully consumed at the end of the grid, the PV power is connected to the grid to prioritize the use of green energy.

[0038] The energy storage battery outputs DC 300-600V, which is connected to a DC / DC converter. The DC / DC converter converts the voltage to 540-700V DC, which is connected to the common DC bus to realize the charging and discharging scheduling of the energy storage battery: Charging mode: When the photovoltaic power is greater than the well site load, the common DC bus outputs power to the DC / DC converter to charge the energy storage battery; Discharging mode: When the photovoltaic power is insufficient or the mains power is interrupted, the energy storage battery discharges to the common DC bus through the DC / DC converter to supplement the load power supply.

[0039] The public power grid outputs 380V AC alternating current, which is supplied to the well site in two paths: one path is connected to the rectification unit, rectified to 540V DC and then connected to the common DC bus to participate in the power dispatching of the DC bus; the other path is directly connected to the backup power frequency loop unit as the emergency power frequency power supply channel for the pumping unit motor.

[0040] The common DC bus is a 540V DC centralized power hub, which supplies power to the pumping unit motor through the following two modes: Variable frequency power supply mode (preferred): The common DC bus outputs 540V DC to multiple inverter units, which are inverted to 380V AC to drive the pumping unit motor; Power frequency backup mode (emergency): The public power grid directly outputs 380V AC to the backup power frequency loop unit to ensure the continuous operation of the pumping unit in case of a failure of the variable frequency system.

[0041] During operation, a multi-energy collaborative method is adopted, specifically: when the light is sufficient, the photovoltaic power is preferentially supplied to local loads (through the DC bus → inverter unit), and the excess power is grid-connected or used to charge the energy storage; when the photovoltaic power is insufficient, the energy storage battery discharges to supplement the power of the DC bus; when it is continuously rainy or the energy storage is out of power, the public power grid is connected to the DC bus through the rectification unit or directly supplied through the power frequency loop to ensure that the load is not interrupted.

[0042] In the embodiment of the present disclosure, in the multi-machine drive intelligent variable frequency integration device of the oil production well site microgrid, the multi-machine drive system uses the common DC bus as the core power hub, and realizes the variable frequency drive and power frequency emergency power supply of multiple pumping units through the rectification unit, multiple inverter units, and backup power frequency loop unit. The electrical connection topology is shown in Figure 4: In the rectification unit, power input and conversion are performed; the DC input path is: the energy storage battery (540V DC) passes through the XT1 DC input terminal block and is connected to the common DC bus through the QF1 DC main circuit breaker. The AC input path is: the public power grid (380V AC) passes through the XT2 AC input terminal block and the QF2 AC main circuit breaker, is connected to the VC rectification unit, rectified to 540V DC and then incorporated into the common DC bus. The braking circuit is: the VC rectification unit is equipped with a ZD braking resistor to absorb the braking energy of the system and ensure the stability of the DC bus voltage.

[0043] Multiple inverter units serve as the main circuit of the variable frequency drive; in this embodiment, the common DC bus supplies power to 5 pumping unit variable frequency loops in parallel, and the topology of each path is the same: common DC bus → QF3 - QF7 DC circuit breakers → HC1 - HC5 buffer units (to suppress the inrush current during power-on) → NB1 - NB5 inverter units (invert 540V DC to 380V AC) → KM1 - KM5 contactors → XT3 - XT7 AC output terminal blocks → 1# - 5# pumping unit motors.

[0044] The backup power frequency circuit unit is used for emergency power redundancy. The public power grid (380V AC) is connected to the power frequency converter switching control module (QH) via the XT1 AC input terminal block and the QF13 AC main circuit breaker, and divided into 5 power frequency circuits: QF8-QF12 AC circuit breakers → KM6-KM10 contactors → CF1-CF5 thermal relays (overload protection) → XT3-XT7 AC output terminal blocks → corresponding pumping unit motor. The switching logic is as follows: when a certain frequency converter circuit (such as the NB1 inverter unit) fails, the power frequency converter switching module (QH) triggers the corresponding power frequency circuit (KM6 contactor engages), achieving uninterrupted emergency power supply.

[0045] In terms of power dispatch, the power from photovoltaic energy storage and public grid rectification is uniformly allocated through a common DC bus, prioritizing the supply to the frequency converter circuit, with redundant power stored in energy storage batteries. Regarding protection mechanisms, DC circuit breakers (QF1, QF3-QF7) and AC circuit breakers (QF2, QF8-QF13) provide overcurrent protection; thermal relays (CF1-CF5) provide overload protection for the power frequency circuit; and buffer units (HC1-HC5) suppress inrush current in the frequency converter circuit.

[0046] In this embodiment, the intelligent control system uses a high-performance edge computing gateway as its core. Through a four-layer architecture of "data acquisition - edge computing - control execution - communication interaction," it achieves intelligent monitoring and collaborative control of well site equipment. The specific topology in this embodiment is shown in Figure 5: Energy system data: The photovoltaic controller, battery management system (BMS), DC / DC converter, and inverter grid-connected system are connected to the edge computing gateway via an RS485 bus, uploading photovoltaic output, energy storage status, and power conversion parameters in real time; Power monitoring data: The electricity meters at the output terminals of the photovoltaic modules, the DC / DC converters, and the public grid input terminals are connected to the power monitoring module via an RS485 bus, and then connected to... The edge computing gateway collects voltage / current / power data from mains power, photovoltaics, and energy storage; equipment status data: rectifier units and multiple inverter units are directly connected to the edge computing gateway via RS485 bus to provide feedback on the operating status of the transmission system; safety and environmental data: patch-type temperature sensors and temperature and humidity sensors are connected to the safety monitoring module via AI analog signals, and then uploaded to the edge computing gateway via RS485 to monitor cabinet temperature and ambient temperature and humidity; pumping unit operating data: load sensors, displacement sensors, and electrical parameter sensors are connected to the pumping unit wellhead acquisition and monitoring system via AI / RS485, and then transmitted wirelessly to the WiFi outdoor AP, and finally uploaded to the edge computing gateway to collect operating parameters such as pumping unit load, displacement, and electrical parameters.

[0047] In this embodiment, the high-performance edge computing gateway acts as the "decision brain," receiving and parsing multi-source data to analyze the energy supply and demand, equipment health, and safety status of the well site in real time; generating control strategies, such as prioritizing energy storage charging when photovoltaic power is sufficient, dynamically adjusting inverter output when load changes suddenly, and triggering alarms when equipment malfunctions; and outputting control commands (DO digital output) to the execution module.

[0048] At the execution level, for the control of the pumping units, the high-performance edge computing gateway outputs start / stop commands to the start / stop control systems of each pumping unit and outputs frequency conversion switching commands to the frequency conversion switching systems of each pumping unit, realizing intelligent start / stop and drive mode switching of the pumping units. During alarm execution, alarm commands are output to the audible and visual alarm system, triggering audible and visual warnings when equipment malfunctions (such as over-limit temperature or pumping unit failure). When the drive system works collaboratively, power dispatch commands are output to the rectifier unit and multiple inverter units to achieve optimized energy allocation on the common DC bus.

[0049] The integrated device in this embodiment can also realize multi-terminal information interconnection. When performing local interaction, the embedded touch screen connects to the industrial switch through the network to realize local visual monitoring and operation. When performing remote interaction, the industrial switch connects to the remote monitoring platform through the network to support remote viewing of the overall status of the well site, historical data, and remote control. When performing wireless interconnection, the WiFi outdoor AP connects to the industrial switch through the network to realize wireless data interaction between the pumping unit wellhead acquisition and monitoring system and the control system.

[0050] Example 2 is based on Example 1 above. As shown in Figure 6, this example specifically uses a well site with 5 11kW pumping units to illustrate the installation and operation process of the integrated device: 1) Integrated device system architecture In this embodiment, the well site equipment uses the integrated device described in this embodiment as the core hub to realize the integrated connection of energy access, load power supply and data monitoring. The specific installation and connection method is as follows: The photovoltaic modules already equipped at the well site are used to lay power cables to connect DC power to the integrated device as green energy input; Mains power: The oilfield public power grid is connected to the integrated device through the "public power grid access" line as basic power supply guarantee.

[0051] The integrated device provides power to the motors of pumping units 1-5 by laying power cables, thereby driving the pumping units to operate.

[0052] Each pumping unit is equipped with a pumping unit data acquisition and monitoring system, which collects pumping unit operating data (such as load, displacement, electrical parameters, etc.) and transmits it wirelessly to an integrated device via WiFi. The integrated device then uploads the well site equipment operating data to a remote monitoring platform via network communication lines, enabling remote visual monitoring and centralized management of the well site status.

[0053] 2) Installation and Wiring: Transport the integrated cabinet to the designated location at the well site and fix the foundation (using cement + red brick pouring, reinforced with brackets); install external wiring, connect the 380V AC mains power to the mains input terminal of the multi-machine drive compartment; connect the photovoltaic modules to the photovoltaic controller input terminal via the combiner box; connect the power supply cables of the 8 pumping units to the load output terminal of the multi-machine drive compartment; deploy the network, configure WiFi-6 outdoor APs to achieve wireless connection with the data acquisition and monitoring system of each oil well pumping unit; connect the edge computing gateway to the oilfield intranet to achieve communication with the upper network.

[0054] 3) Operation and control strategy under normal sunlight conditions: The photovoltaic installed capacity is 60kW with an average daily power generation of ≥280kWh. The photovoltaic DC controller and DC-DC converter form a stable 550V DC connected to the common DC bus, driving 5 pumping units (11KW) to continuously produce at high frequency. Excess electricity is charged through the photovoltaic controller's energy storage battery. Under continuous normal sunlight conditions, after the battery is fully charged, excess electricity is connected to the public grid through the inverter grid connection system.

[0055] Low light conditions: When there is insufficient sunlight, the energy storage battery discharges to supplement the insufficient photovoltaic power; when the energy storage SOC drops to 20%, it automatically switches to mains power supply.

[0056] Fault conditions: If an inverter unit fails, the backup contactor of the power frequency circuit will engage to supply power to the corresponding pumping unit; if the cable joint temperature exceeds 80°C, the safety monitoring module will trigger a voice alarm and simultaneously cut off the power supply to that circuit, resetting after the fault is cleared.

[0057] 4) Verification of operational effects: In this embodiment, after the device is in operation: the photovoltaic absorption rate increases from 58% to 91%, the average daily grid power consumption decreases from 300kWh to ≤30kWh, and green electricity is fully utilized; the energy mutual feedback of multi-machine transmission reduces the average daily power consumption of a single well from 60kWh to 42kWh, and the annual power saving of 5 wells is 32,400kWh, with obvious energy-saving effect.

Claims

1. A multi-machine drive intelligent frequency conversion integrated device for microgrids in oil well sites, characterized in that: The system includes an integrated cabinet; the integrated cabinet is configured with an energy storage compartment, a multi-machine drive compartment, and a control and display compartment; the integrated cabinet houses a photovoltaic energy storage system, a multi-machine drive system, and a well site intelligent control system; the photovoltaic energy storage system is located in the energy storage compartment; the multi-machine drive system is located in the multi-machine drive compartment; the well site intelligent control system is located in the control and display compartment; the photovoltaic energy storage system is connected to both the multi-machine drive system and the well site intelligent control system; the multi-machine drive system is connected to the well site intelligent control system.

2. The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site according to claim 1, characterized in that: The photovoltaic energy storage system includes a photovoltaic controller, a DC-DC converter, a battery management system, an inverter grid-connected system, and an energy storage battery; the photovoltaic controller is connected to both the energy storage battery and the inverter grid-connected system; the energy storage battery is connected to both the battery management system and the DC-DC converter; and the battery management system is connected to the DC-DC converter.

3. The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site according to claim 2, characterized in that: The multi-machine drive system includes a common DC bus unit, a rectifier unit, an inverter unit, and a backup power frequency circuit unit; the rectifier unit, common DC bus unit, and inverter unit are connected in sequence to form a frequency conversion circuit; the rectifier unit is connected to the public power grid; the common DC bus unit is connected to the aforementioned DC-DC converter; the inverter unit and the backup power frequency circuit unit each include several groups; the output end of the inverter unit is connected to an oil pumping unit.

4. The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site according to claim 3, characterized in that: The well site intelligent control system includes an edge computing gateway, an industrial switch, an outdoor WiFi access point (AP), an embedded touchscreen, a power monitoring module, and a security monitoring module. The power monitoring module includes a smart meter and supporting sensors. The industrial switch, outdoor WiFi AP, embedded touchscreen, power monitoring module, and security monitoring module are all connected to the edge computing gateway. The industrial switch is connected to the outdoor WiFi AP. The edge computing gateway is connected to the aforementioned photovoltaic controller, battery management system, DC-DC converter, and inverter grid-connected system. The edge computing gateway is also connected to the aforementioned rectifier unit and inverter unit.

5. The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site according to claim 3, characterized in that: The inverter unit includes a DC circuit breaker, a buffer, an inverter, a first AC contactor, and an output terminal block connected in sequence; the DC circuit breaker is connected to the common DC bus unit; the output terminal block is connected to the oil pumping unit via a power supply cable.

6. The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site according to claim 5, characterized in that: The backup power frequency circuit unit includes an AC circuit breaker, a second AC contactor, and a thermal relay connected in sequence; the output terminal of the thermal relay is connected to the output terminal block of the aforementioned inverter unit.

7. The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site according to claim 4, characterized in that: The safety monitoring module includes a patch-type temperature sensor, an internal temperature and humidity sensor, and a voice alarm unit; patch-type temperature sensors are installed on the DC-DC converter, the public power grid, the common DC bus unit, and the inverter unit; internal temperature and humidity sensors are installed in the energy storage compartment, the multi-machine drive compartment, and the control and display compartment; the voice alarm unit is located on the top of the cabinet.

8. The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site according to claim 1, characterized in that: The control and display compartment is equipped with a secondary door; the secondary door has an opening for mounting an embedded touch screen.

9. The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site according to claim 7, characterized in that: The photovoltaic controller is externally connected to distributed photovoltaic modules at the well site; the inverter grid-connected system, rectifier unit, and backup power frequency circuit unit are all connected to the public power grid; the inverter unit and backup power frequency circuit unit are both connected to the pumping unit motor at the well site; the battery management system monitors the voltage, current, temperature, and remaining capacity of the energy storage battery in real time and controls the charging and discharging process of the energy storage battery; when the real-time power generation of the external photovoltaic modules is greater than the sum of the charging power of the energy storage battery and the load power of the pumping unit, it automatically switches to the inverter grid-connected system to invert the photovoltaic DC power into AC power and connect it to the public power grid; the power monitoring module collects data from the input terminal of the public power grid and the photovoltaic modules. The voltage, current, power, and energy data of the output terminals, the energy storage battery output terminals, and the well site pumping unit are transmitted to the edge computing gateway via an industrial switch. The edge computing gateway analyzes the data to generate power optimization strategies. When the photovoltaic power is greater than the load power, it controls the energy storage battery to charge; when the photovoltaic power is less than the load power, it controls the energy storage battery to discharge; when the public power grid is interrupted, it triggers emergency power supply from the energy storage. The patch-type temperature sensor monitors the temperature of the cable joints in the aforementioned DC-DC converter, public power grid, common DC bus unit, and inverter unit; the cabinet temperature and humidity sensor monitors environmental parameters; and in case of abnormality, it triggers a voice alarm and cuts off the corresponding circuit.

10. The integrated intelligent frequency conversion device for multi-machine drive in a microgrid at an oil well site according to claim 9, characterized in that: The braking energy of the well site pumping unit is fed back to the common DC bus via the inverter unit.

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