Airport distributed energy storage intermediate frequency power supply control system

Abstract

The invention provides an airport distributed energy storage medium-frequency power supply control system, and belongs to the technical field of airport distributed energy storage medium-frequency power supply control. In order to solve the technical problems that an existing gallery bridge static variable power supply is long in power supply distance, large in cable voltage drop, poor in electric energy quality and incapable of dealing with sudden power failure, an energy storage power supply cabinet is arranged below the movable end of each gallery bridge of an airport, and an energy storage battery module, a bidirectional converter, an intermediate frequency inversion module and an intelligent control system are arranged in each energy storage power supply cabinet. The power input end of the bidirectional converter is connected with the mains supply interface through an input cable, the power output end of the bidirectional converter is connected with the power input ends of the energy storage battery module and the intermediate frequency inversion module, and the power output end of the energy storage battery module is further connected with the power input end of the intermediate frequency inversion module. The output end of the intermediate-frequency inversion module is connected with a power supply module of an airplane parked beside the gallery bridge through an output cable; the system is applied to airport ground power supply.

Description

Technical Field

[0001] This invention provides a medium-frequency power supply control system for airport distributed energy storage, belonging to the field of medium-frequency power supply control technology for airport distributed energy storage. Background Technology

[0002] When aircraft are undergoing maintenance and starting up on the ground, they typically require 400Hz intermediate frequency AC power from ground power sources to ensure the normal operation of cabin lighting, avionics checks, and air conditioning systems, while also minimizing fuel consumption by the aircraft's auxiliary power unit and reducing emissions and noise. Currently, ground power is primarily supplied by a centralized 400Hz static power supply system. This system centralizes high-power static power supplies at a power center at a remote location within the airport, transmitting 400Hz power to each boarding bridge via long-distance (usually exceeding several hundred meters) heavy-duty cables for aircraft use. However, this power supply solution has the following drawbacks: Deterioration of power quality: Long-distance power transmission leads to large energy loss on cables, large voltage drop and increased harmonic interference, making it difficult to guarantee voltage stability and waveform purity at the aircraft interface at the end of the jet bridge, which may affect the precision equipment of the aircraft. Power supply reliability risk: If the central static transformer power supply or the main cable fails, multiple corridor bridges will lose power at the same time. The system will be completely dependent on the mains power and will lack backup power. The mains power interruption or fluctuation will directly cause the ground power supply to be interrupted, and the entire ground power supply system will be paralyzed, posing a safety hazard. Uneconomical operation: The cost of using long-distance, large-section cables for power transmission is high, and the cables themselves have huge energy losses. The system cannot utilize off-peak electricity at night, resulting in high operating costs. The power supply control is not intelligent: the charging strategy is simplistic and cannot adapt to the adaptive adjustment of the power supply strategy under complex scenarios such as grid fluctuations, and cannot achieve reasonable interaction with the grid.

[0003] Therefore, there is an urgent need to develop an airport power supply solution that is flexible in deployment, has high power quality, is capable of uninterrupted power supply, and can intelligently adapt to changes in the power grid. Summary of the Invention

[0004] To address the technical problems existing in the background art, the present invention adopts the following technical solution: A distributed energy storage medium-frequency power supply control system for airports is provided, comprising an energy storage power cabinet installed below the movable end of each boarding bridge in the airport. The energy storage power cabinet contains an energy storage battery module, a bidirectional converter, a medium-frequency inverter module, and an intelligent control system. The power input terminal of the bidirectional converter is connected to the mains power interface via an input cable. The power output terminal of the bidirectional converter is connected to the power input terminals of the energy storage battery module and the medium-frequency inverter module, respectively. The power output terminal of the energy storage battery module is also connected to the power input terminal of the medium-frequency inverter module. The output of the intermediate frequency inverter module is connected to the power module of the aircraft parked next to the jet bridge via an output cable. The control terminals of the energy storage battery module, bidirectional converter, and medium-frequency inverter module are all connected to the intelligent control system.

[0005] The power input terminal of the bidirectional converter is also connected to the photovoltaic power supply module via an input cable.

[0006] The energy storage battery module specifically uses lithium iron phosphate battery packs or lithium titanate battery packs as energy storage media.

[0007] The energy storage battery module is specifically connected to the system DC bus via a buck-boost converter, and the buck-boost converter is used to match the output voltage of the energy storage battery module with the operating voltage on the DC bus.

[0008] The buck-boost converter specifically adopts a control circuit for a non-isolated buck-boost converter, and the operation method of the control circuit is as follows: By adjusting the on and off times of each semiconductor power switch, the current in inductors L1, L2, and L3 is forced to flow in the desired direction. When the energy storage battery module discharges, the current in each inductor flows from the battery side to the bus side. When the energy storage battery module is charging, the current flows from the bus side to the battery side.

[0009] The bidirectional converter employs a power semiconductor switching control method combined with SVPWM modulation and a dual closed-loop control method to convert AC power to DC power. The specific method is as follows: Real-time monitoring of grid voltage and frequency: When the grid voltage and frequency are within the preset normal fluctuation range, the constant current-constant voltage standard charging mode is adopted; when the grid voltage or frequency is detected to be outside the normal range but still within the equipment's tolerance range, the charging power is automatically reduced or charging is paused. The bidirectional converter uses a non-isolated circuit. By setting multiple power semiconductor switching transistors and controlling them with SPWM or SVPWM, the current on the filter inductor L changes sinusoidally. By adjusting the direction and magnitude of the current, the DC bus voltage can be controlled and energy can flow bidirectionally.

[0010] When the medium-frequency inverter module is working, it directly draws DC power from the energy storage battery module, or outputs DC power through a bidirectional converter. The control circuit of the intermediate frequency inverter module includes power semiconductor switching transistors, a transformer, and a filter circuit. Specifically, it consists of a three-phase inverter bridge composed of six power semiconductor switching transistors. The output waveform changes sinusoidally relative to the midpoint of the input capacitor at the intermediate frequency. In addition to the fundamental frequency component, the output waveform also contains high-frequency harmonic components. The filter circuit, composed of the transformer leakage inductance and the output filter capacitor, is used to filter out harmonics. The transformer is used for voltage adaptation to ensure that the output voltage range meets the requirements. The working method of the intermediate frequency inverter module is as follows: After high-voltage DC power is input to the intermediate frequency inverter module, it passes through the soft starter circuit and is then input to the filter circuit. The DC / AC module operates under SPWM to invert the DC power into intermediate frequency AC power, which is then filtered by the filter circuit to output a smooth sinusoidal AC power.

[0011] The control method used in the intelligent control system is as follows: The mains power is transmitted through a bidirectional converter to the intermediate frequency inverter module, and then supplied to the electrical equipment via the output cable using the following adaptive control strategy: When the mains power supply is stable and the power supply capacity is sufficient, the system controls the charging of the energy storage battery module. The charging power matching is achieved by adjusting the average power of the bidirectional converter. When the medium frequency load power fluctuates for a short time, the energy storage battery module releases or absorbs excess energy for a short time. When the mains power supply experiences a short-term power shortage, low voltage, or grid disconnection, the intelligent control system controls each module to perform energy conversion in the following manner: The control system supplies power to the bidirectional converter and the intermediate frequency inverter module, and the energy storage battery module feeds energy back to the local power grid to support local power load. The power supply capacity is adjusted according to the state of charge of the energy storage battery module.

[0012] The advantages of this invention compared to existing technologies are as follows: This invention provides an airport distributed energy storage intermediate frequency power supply control system, which adopts a distributed energy storage intermediate frequency power supply design under the jet bridge, integrating mains power and energy storage dual power supply to ensure power output stability. The system uses energy storage batteries and adaptive grid charging. When the grid is stable, it executes the optimal charging curve, rectifying the AC mains power into DC power to charge the battery. When a sudden rise / fall or frequency fluctuation in grid voltage is detected, the controller will intelligently reduce the charging power or enter standby mode. The system has built-in large-capacity energy storage and millisecond-level seamless switching function, giving it the characteristics of an uninterruptible power supply, which can effectively cope with faults such as mains power interruption and fluctuation, greatly improving flight support capabilities. The system adopts a modular setting and standardized modular design, which is convenient to install and simple to maintain. The battery pack used supports online replacement and expansion, and the system capacity can be flexibly adjusted according to future flight volume growth. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the circuit structure of the airport distributed energy storage intermediate frequency power supply control system of the present invention; Figure 2 This is a circuit diagram of the first scheme for connecting the energy storage battery module according to the present invention; Figure 3 This is a circuit diagram of the second scheme for connecting the energy storage battery module according to the present invention; Figure 4 This is a circuit diagram of the non-isolated buck-boost circuit in the energy storage battery module of the present invention; Figure 5 This is a circuit diagram of a bidirectional converter used in an embodiment of the present invention; Figure 6 This is a circuit diagram of a medium-frequency inverter module used in an embodiment of the present invention. Detailed Implementation

[0014] This invention addresses the problems of existing fixed 400Hz static power supplies for jet bridges, such as long power supply distances, large cable voltage drops, poor power quality, and inability to handle sudden power outages. It proposes a distributed, modular airport distributed energy storage medium-frequency power supply control system. This system includes an energy storage power cabinet deployed beneath the movable end of each jet bridge. The cabinet integrates energy storage battery modules, a bidirectional converter, a medium-frequency inverter module, and an intelligent control system. The energy storage battery modules are charged from the mains interface at the fixed end of the jet bridge via the bidirectional converter, or supplemented with energy from renewable energy sources such as photovoltaics. The medium-frequency inverter module converts DC power to 400Hz medium-frequency AC power, directly powering parked aircraft. This invention shortens the power supply distance, improves power quality and reliability, features seamless switching between grid and off-grid operation, and can utilize peak-valley electricity price differences to reduce operating costs, achieving green, efficient, and safe ground power supply for jet bridges.

[0015] like Figure 1 As shown, this invention provides an airport distributed energy storage medium-frequency power supply control system, mainly composed of energy storage battery modules, bidirectional converters, medium-frequency inverter modules, and intelligent control system modules, wherein: As the energy core of the system, the energy storage battery module specifically uses lithium iron phosphate battery packs, lithium titanate battery packs, or other batteries with high energy density and long cycle life as energy storage media. Its total capacity is precisely calculated to ensure that it can provide at least full-load power supply for typical aircraft (such as Airbus A320 or Boeing B737 series) after the power grid is interrupted.

[0016] The bidirectional converter connects the energy storage battery to the mains power (50Hz, 380V) at the fixed end of the bridge. It is not only a battery charger but also has the ability to feed power back to the grid. It also has an adaptive grid charging function: the built-in monitoring circuit collects the grid voltage and frequency in real time. When the grid is stable, it executes the optimal charging curve to rectify the AC power from the mains to DC power to charge the battery. When a sudden rise / fall in grid voltage or frequency fluctuation is detected, the controller will intelligently reduce the charging power or enter standby mode to avoid exacerbating grid anomalies and protect its own equipment. When needed, it can also invert the DC power from the battery to AC power to feed back to the local grid (in power compensation mode).

[0017] The intermediate frequency inverter module draws DC power directly from the energy storage battery module and generates stable and pure 400Hz / 200V intermediate frequency AC power through high-precision power electronic conversion methods (such as using three-level NPC topology and SVPWM modulation). Furthermore, since the power cabinet is located close to the aircraft, the output cable is extremely short (usually less than 20 meters), which completely eliminates the voltage drop and loss problems of long-distance power transmission and ensures power quality.

[0018] The intelligent control system, acting as the system's brain, is built upon a high-performance processor and coordinates the control of all the aforementioned unit modules. Its core control methods (strategy logic) include: Real-time grid status monitoring: The system monitors mains power quality in real time. Upon detecting a power outage (e.g., voltage below a threshold or frequency anomaly), it immediately issues a trip command to disconnect the grid and simultaneously instructs the intermediate frequency inverter to establish a stable off-grid voltage, achieving seamless switching and ensuring uninterrupted power supply to aircraft instruments. In off-grid mode, it precisely controls the intermediate frequency inverter to output a constant voltage and frequency 400Hz power supply. Charging and discharging logic management: Control the start-up, shutdown, and power of the bidirectional converter according to preset strategies (such as peak-valley electricity pricing) or cloud platform instructions; Battery Management System (BMS) Collaboration: Monitors the battery's SOC (State of Charge) and SOH (State of Health) to achieve balanced management and safety protection; Data communication: Upload data to the cloud management platform via 4G / 5G, Ethernet, or other communication methods.

[0019] The airport distributed energy storage intermediate frequency power supply control system provided by this invention can output single-phase AC 115 / 200V, 400Hz power or three-phase AC 115 / 200V, 400Hz power. The power supply system adopts three-phase four-wire, with a rated voltage of 115 / 200V, a steady-state voltage range of 113-118V, a crest factor of 1.414±0.07, and a voltage modulation of ≤2.5V (RMS value). It adopts a three-phase four-wire connection of A, B, C, and N. Each module of the system is equipped with protection functions, and faults can be queried and diagnosed through a human-machine interface. The specific protection indicators meet the requirements of GJB572A and MH / T 6018.

[0020] like Figure 1 As shown, in use, the mains power (50Hz, 380V) at the fixed end of the boarding bridge passes through a bidirectional converter to the intermediate frequency inverter module, and finally supplies intermediate frequency power to the electrical equipment (aircraft) through the output cable. The intelligent control system controls and monitors each module. When the mains power at the fixed end of the boarding bridge is below the threshold or a frequency abnormality occurs, the intelligent control system will switch to the working mode of energy storage battery module to bidirectional converter and then to intermediate frequency inverter module in order to ensure the stability of the constant voltage and constant frequency 400Hz power output of the intermediate frequency inverter module. In the mains power supply mode, the intelligent control system can determine the working strategy of the bidirectional converter according to the power of the output electrical load equipment. When the power allows, the bidirectional converter can be controlled to supply power to the energy storage battery module and the intermediate frequency inverter module at the same time, realizing the dual working mode operation of energy storage battery module charging and maintenance and load electrical equipment.

[0021] At night (off-peak hours), the intelligent control system prioritizes using the mains power (50Hz, 380V) from the fixed end of the bridge to power the aircraft through the intermediate frequency inverter module, while simultaneously charging the energy storage battery module. During the day (peak hours / flights docked at the bridge), ground staff plug the aircraft power plug into the standard interface on the cabinet, and the intelligent control system prioritizes using battery power to power the aircraft through the intermediate frequency inverter module. If the battery power is insufficient, it automatically switches to direct mains power supply and simultaneously replenishes the battery power. When the mains power fails, the intelligent control system immediately disconnects the mains contactor after detecting the mains power anomaly, and the intermediate frequency inverter module seamlessly switches to the battery module to continue powering the aircraft, ensuring that flight operations are not affected. Throughout the entire control process, all operating parameters, including voltage, current, battery SOC, fault codes, and other data, are uploaded to the airport energy management cloud platform in real time, enabling visualized monitoring and intelligent operation and maintenance.

[0022] The energy storage battery module used in this invention preferentially adopts lithium titanate batteries as the energy storage medium. The battery capacity is prioritized to ensure the power quality of the aircraft for 15-30 minutes after a power grid outage. Users can select the energy storage medium and battery capacity according to their own power needs and regulations. The energy storage battery module is equipped with a BMS management system, which can detect the battery's SOC (State of Charge), SOH (State of Health), and battery voltage and temperature, and realize equalization management, thermal management and safety early warning. At the same time, it can integrate new energy sources such as rooftop photovoltaics to realize "green electricity" for aircraft and reduce airport carbon emissions.

[0023] In practical use, the energy storage battery module is connected to the system in two ways: Method 1: Connect the battery directly to the DC bus, such as... Figure 2 As shown, this method has relatively high requirements for the voltage level of the battery, which needs to be compatible with the operating voltage range of the bidirectional converter and the medium frequency inverter module. For example, if the voltage of the bidirectional converter is above 540V, then the voltage of the battery after series connection is more suitable at 600~800V. Method 2: The battery is connected to the system DC bus via a buck-boost converter. A buck-boost module is used to match the battery output voltage with the bus operating voltage. Figure 3 As shown, this method has relatively lenient requirements on the series voltage of the battery pack, and can be applied to battery packs ranging from 400V to 800V.

[0024] The circuit structure of the buck-boost converter connected to the energy storage battery module using method 2 can take many forms, including isolated DC / DC circuits and non-isolated DC / DC circuits. Regardless of whether it is an isolated or non-isolated circuit, its operation requires the following two characteristics: 1. Matching the battery voltage with the bus voltage so that fluctuations in the battery voltage during charging and discharging do not affect the bus voltage; 2. Having high energy conversion efficiency to avoid energy loss. Figure 4 This diagram illustrates a non-isolated buck-boost circuit. During operation, the circuit adjusts the on and off times of the semiconductor power switches to force the current in inductors L1, L2, and L3 to flow in the desired direction. When the battery discharges, the inductor current flows from the battery side to the bus side; when the battery charges, the current flows from the bus side to the battery side. Different on and off times of the semiconductor power switches not only change the current direction to switch between charging and discharging functions but also adapt to different battery voltages.

[0025] In embodiments of the present invention, the bidirectional converter is configured to perform adaptive grid charging, primarily for efficient conversion between AC and DC power supplies. Based on power semiconductor switching control, and combined with corresponding control algorithms (such as SVPWM modulation and dual closed-loop control), it achieves bidirectional energy transfer and precise regulation, specifically including: The system monitors the voltage and frequency of the power grid in real time. When the voltage and frequency of the power grid are within the preset normal fluctuation range, it adopts the constant current-constant voltage standard charging mode. When the voltage or frequency of the power grid is detected to be outside the normal range but still within the tolerance range of the equipment, it automatically reduces the charging power or suspends charging to reduce the impact on the power grid and protect its own equipment.

[0026] The bidirectional converter controls the current direction through high-frequency switching to achieve AC-DC conversion. At the same time, a filter circuit is added to the circuit to ensure the high quality of the output power. The bidirectional converter can realize efficient bidirectional power conversion and intelligent management, and has the beneficial effects of flexible mode switching, fast dynamic response and reliable protection mechanism.

[0027] The bidirectional converter circuit can be either isolated or non-isolated. Non-isolated circuits are simpler in structure and lower in cost, while isolated circuits offer higher security. Different circuit types can be selected based on actual needs. Figure 5 The circuit topology of a non-isolated bidirectional converter is shown. By setting up 6 power semiconductor switches, the current on the filter inductor L changes sinusoidally based on the SPWM (or SVPWM) control of the semiconductor switches. By adjusting the direction and magnitude of the current, the DC bus voltage can be controlled and the energy can flow bidirectionally.

[0028] In embodiments of the present invention, the intermediate frequency inverter module directly draws DC power from the lithium battery energy storage module or uses a DC power supply converted by a bidirectional converter for output. The intermediate frequency inverter module is mainly used to output intermediate frequency inverter power, so that the high voltage DC input is converted into intermediate frequency AC power by the DC / AC module SPWM operation after passing through the soft start circuit and input filtering, and then becomes smooth sinusoidal AC power after being filtered by the output filter circuit.

[0029] Figure 6 The circuit structure of a medium-frequency inverter module is shown. The circuit consists of power semiconductor switching transistors, a transformer, and a filter circuit. A three-phase inverter bridge is formed by six power semiconductor switching transistors. The output waveform changes sinusoidally relative to the midpoint of the input capacitor at the medium frequency. In addition to the medium-frequency fundamental component, the output waveform also contains high-frequency harmonic components. The filter circuit, composed of the transformer leakage inductance and the output filter capacitor, can filter out harmonics, so that the output waveform meets the relevant standard requirements. The transformer T1 in the figure is mainly used for voltage adaptation, so that the output voltage range meets the requirements.

[0030] In embodiments of the present invention, the intelligent control system employs an industrial-grade multi-core processor to run a real-time operating system. Its main functions include formulating charging and discharging logic management strategies, seamless switching control between grid and off-grid systems, and coordination with the battery management system (BMS).

[0031] Under normal operating conditions, the intelligent control system controls each module to complete the following energy conversion control process: The mains power (50Hz, 380V) is transmitted through a bidirectional converter to the intermediate frequency inverter module, and then supplied to the electrical equipment (aircraft) via the output cable to provide intermediate frequency power, thereby achieving the following adaptive control: When the mains power supply is stable and the power supply capacity is sufficient, the power matching of the battery is achieved by adjusting the average power of the bidirectional converter. When the medium frequency load power fluctuates for a short time, the battery releases or absorbs excess energy for a short time, which helps to improve the power impact of the load. When the mains power supply experiences a short-term power shortage, low voltage, or grid disconnection (due to excessive local loads), the intelligent control system ensures the stability of the constant voltage and frequency 400Hz power output from the frequency inverter module. It controls each module to perform energy conversion in the following manner: Power is transferred from the energy storage battery module to the bidirectional converter and the medium-frequency inverter module. In addition to ensuring local power supply, the energy storage battery module can also feed energy back to the local grid to support other local electrical loads. Power capacity is adjusted based on the battery's state of charge.

[0032] In addition, when the power grid has peak and off-peak pricing, during off-peak pricing, the intelligent control system will prioritize using the mains power (50Hz, 380V) at the fixed end of the bridge to power the aircraft through the intermediate frequency inverter module, while charging the energy storage battery module; during peak power periods / when the flight is docked at the bridge, the intelligent control system will prioritize using the battery to power the aircraft through the intermediate frequency inverter module; if the battery power is insufficient, it will automatically switch to direct mains power supply and simultaneously replenish the battery power.

[0033] In case of mains power failure: After detecting an abnormality in the mains power, the intelligent control system can immediately disconnect the mains power contactor, and the intermediate frequency inverter module can seamlessly switch over to continue power supply from the battery, so as to achieve uninterrupted power supply to the load and ensure that flight operations are not affected.

[0034] The intelligent control system can also be interconnected with the upper-level system to achieve visualized monitoring and intelligent operation and maintenance through data transmission; the data transmission includes the operating parameters of all modules: voltage, current, battery SOC, fault codes, etc., which can be uploaded to the airport energy management cloud platform in real time.

[0035] This invention integrates mains power and energy storage with a distributed energy storage intermediate frequency power supply installed under the jet bridge, ensuring stable power output. During operation, it utilizes energy storage batteries and an adaptive grid for charging. When the grid is stable, it executes the optimal charging curve, rectifying the AC mains power into DC power to charge the battery. When a sudden rise / fall in grid voltage or frequency fluctuation is detected, the controller intelligently reduces the charging power or enters standby mode. The system's built-in large-capacity energy storage and millisecond-level seamless switching function give it UPS (Uninterruptible Power Supply) characteristics, effectively handling mains power interruptions and fluctuations, greatly improving flight support capabilities. It can utilize off-peak electricity at night to charge the battery and discharge it to power aircraft during peak days, profiting from the electricity price difference. This invention has minimal power impact on the airport grid, avoiding grid modifications required for adding high-power equipment, and can integrate rooftop photovoltaic and other new energy sources to achieve "green electricity" for aircraft, reducing airport carbon emissions. The system adopts a standardized and modular design, making installation convenient and maintenance simple. The battery pack supports online replacement and expansion, allowing for flexible adjustment of system capacity according to future flight volume growth.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A distributed energy storage medium-frequency power supply control system for airports, comprising an energy storage power supply cabinet installed below the movable end of each boarding bridge in the airport, characterized in that: The energy storage power cabinet is equipped with an energy storage battery module, a bidirectional converter, a medium-frequency inverter module and an intelligent control system. The power input terminal of the bidirectional converter is connected to the mains interface through an input cable. The power output terminal of the bidirectional converter is connected to the power input terminals of the energy storage battery module and the medium-frequency inverter module respectively. The power output terminal of the energy storage battery module is also connected to the power input terminal of the medium-frequency inverter module. The output of the intermediate frequency inverter module is connected to the power module of the aircraft parked next to the jet bridge via an output cable. The control terminals of the energy storage battery module, bidirectional converter, and medium-frequency inverter module are all connected to the intelligent control system.

2. The airport distributed energy storage medium-frequency power supply control system according to claim 1, characterized in that: The power input terminal of the bidirectional converter is also connected to the photovoltaic power supply module via an input cable.

3. The airport distributed energy storage intermediate frequency power supply control system according to claim 1, characterized in that: The energy storage battery module specifically uses lithium iron phosphate battery packs or lithium titanate battery packs as energy storage media.

4. The airport distributed energy storage intermediate frequency power supply control system according to claim 1, characterized in that: The energy storage battery module is specifically connected to the system DC bus via a buck-boost converter, and the buck-boost converter is used to match the output voltage of the energy storage battery module with the operating voltage on the DC bus.

5. The airport distributed energy storage intermediate frequency power supply control system according to claim 4, characterized in that: The buck-boost converter specifically adopts a control circuit for a non-isolated buck-boost converter, and the operation method of the control circuit is as follows: By adjusting the on and off times of each semiconductor power switch, the current in inductors L1, L2, and L3 is forced to flow in the desired direction. When the energy storage battery module discharges, the current in each inductor flows from the battery side to the bus side. When the energy storage battery module is charging, the current flows from the bus side to the battery side.

6. The airport distributed energy storage intermediate frequency power supply control system according to claim 1, characterized in that: The bidirectional converter employs a power semiconductor switching control method combined with SVPWM modulation and a dual closed-loop control method to convert AC power to DC power. The specific method is as follows: Real-time monitoring of grid voltage and frequency: When the grid voltage and frequency are within the preset normal fluctuation range, the constant current-constant voltage standard charging mode is adopted; when the grid voltage or frequency is detected to be outside the normal range but still within the equipment's tolerance range, the charging power is automatically reduced or charging is paused. The bidirectional converter uses a non-isolated circuit. By setting multiple power semiconductor switching transistors and controlling them with SPWM or SVPWM, the current on the filter inductor L changes sinusoidally. By adjusting the direction and magnitude of the current, the DC bus voltage can be controlled and energy can flow bidirectionally.

7. The airport distributed energy storage intermediate frequency power supply control system according to claim 1, characterized in that: When the medium-frequency inverter module is working, it directly draws DC power from the energy storage battery module, or outputs DC power through a bidirectional converter. The control circuit of the intermediate frequency inverter module includes power semiconductor switching transistors, a transformer, and a filter circuit. Specifically, it consists of a three-phase inverter bridge composed of six power semiconductor switching transistors. The output waveform changes sinusoidally relative to the midpoint of the input capacitor at the intermediate frequency. In addition to the fundamental frequency component, the output waveform also contains high-frequency harmonic components. The filter circuit, composed of the transformer leakage inductance and the output filter capacitor, is used to filter out harmonics. The transformer is used for voltage adaptation to ensure that the output voltage range meets the requirements. The working method of the intermediate frequency inverter module is as follows: After high-voltage DC power is input to the intermediate frequency inverter module, it passes through the soft starter circuit and is then input to the filter circuit. The DC / AC module operates under SPWM to invert the DC power into intermediate frequency AC power, which is then filtered by the filter circuit to output a smooth sinusoidal AC power.

8. The airport distributed energy storage medium-frequency power supply control system according to claim 1, characterized in that: The control method used in the intelligent control system is as follows: The mains power is transmitted through a bidirectional converter to the intermediate frequency inverter module, and then supplied to the electrical equipment via the output cable using the following adaptive control strategy: When the mains power supply is stable and the power supply capacity is sufficient, the system controls the charging of the energy storage battery module. The charging power matching is achieved by adjusting the average power of the bidirectional converter. When the medium frequency load power fluctuates for a short time, the energy storage battery module releases or absorbs excess energy for a short time. When the mains power supply experiences a short-term power shortage, low voltage, or grid disconnection, the intelligent control system controls each module to perform energy conversion in the following manner: The control system supplies power to the bidirectional converter and the intermediate frequency inverter module, and the energy storage battery module feeds energy back to the local power grid to support local power load. The power supply capacity is adjusted according to the state of charge of the energy storage battery module.

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