Wind-hydrogen DC bus integrated cabinet and wind-hydrogen coupled power generation system

Abstract

The application provides a wind-hydro direct-current bus integrated cabinet and a wind-hydro coupling power generation system, and relates to the field of wind power electrical equipment.The cabinet body is internally divided into a bus area, a rectification unit area, a buffer energy storage area and an output area;the common direct-current bus is arranged in the bus area;the multi-machine rectification interface module is arranged in the rectification unit area, and a plurality of parallel input terminals thereof are used for connecting a plurality of wind turbines;the buffer energy storage module is arranged in the buffer energy storage area and is connected across the common direct-current bus;the electrolytic tank output module is arranged in the output area and comprises a main circuit breaker, a pre-charging current limiting unit and a direct-current output terminal which are connected in series, the main circuit breaker is connected with the common direct-current bus, and the direct-current output terminal is used for connecting the electrolytic tank;the monitoring and protection unit is arranged in the output area and is electrically connected with the common direct-current bus, the multi-machine rectification interface module, the buffer energy storage module and the electrolytic tank output module.The scheme can effectively inhibit the circulating current and the direct-current bus ripple when the multiple machines are connected in parallel.

Description

Technical Field

[0001] This application relates to the field of wind power electrical equipment, specifically to integrated wind-hydrogen DC bus cabinets and wind-hydrogen coupled power generation systems. Background Technology

[0002] With the acceleration of the global energy transition, hydrogen energy, as a clean and efficient secondary energy source, has attracted much attention for its development and utilization. Among them, the "wind-hydrogen coupling" model, which uses surplus wind power to electrolyze water to produce hydrogen, is regarded as an effective way to solve the problem of wind power consumption and realize the large-scale production of green hydrogen.

[0003] Currently, wind power hydrogen production systems mostly adopt a series-connected distributed structure of "wind turbine generator - converter - rectifier cabinet - electrolyzer". In this existing technical solution, each functional unit is an independent device, distributed and connected by external cables. However, this split layout of wind power hydrogen production systems results in several problems. First, it leads to a large equipment footprint and complex wiring, resulting in high power plant construction costs and significant inconvenience for on-site installation and subsequent maintenance. Second, when multiple turbines are connected in parallel, circulating currents can easily occur between rectifier branches, leading to energy loss. Furthermore, excessive DC bus voltage ripple and frequent current surges often occur, severely impacting the lifespan of the electrolyzer. Utility Model Content

[0004] To address the aforementioned issues, this application provides an integrated wind-hydrogen DC bus cabinet and a wind-hydrogen coupled power generation system. By reconstructing the DC power supply system for wind-powered hydrogen production from both physical space and electrical connection dimensions, it can effectively suppress circulating current and DC bus ripple when multiple generators are connected in parallel.

[0005] This application is implemented as follows: In a first aspect, this application provides an integrated wind-hydrogen DC bus cabinet, comprising: a cabinet body internally divided into a bus area, a rectifier unit area, a buffer energy storage area, and an output area; a common DC bus located in the bus area; a multi-generator rectifier interface module located in the rectifier unit area, including several parallel input terminals for connecting the outputs of multiple wind turbine generators to the common DC bus; a buffer energy storage module located in the buffer energy storage area and connected across both sides of the common DC bus for suppressing DC ripple; an electrolyzer output module located in the output area, including a main circuit breaker, a pre-charge current limiting unit, and a DC output terminal connected in series, wherein the end of the main circuit breaker away from the pre-charge current limiting unit is connected to the common DC bus, and the end of the DC output terminal away from the pre-charge current limiting unit is used to connect to an external electrolyzer; and a monitoring and protection unit located in the output area, which is electrically connected to the common DC bus, the multi-generator rectifier interface module, the buffer energy storage module, and the electrolyzer output module, respectively.

[0006] In some implementations of this application, at least one of the multi-machine rectifier interface module, buffer energy storage module, and electrolytic cell output module is installed in the cabinet using a drawer-type structure, and the drawer-type structure includes a mechanical interlocking structure with the corresponding isolating circuit breaker or main circuit breaker.

[0007] In some implementations of this application, the buffer energy storage module includes a thin-film capacitor bank unit and a supercapacitor bank unit. The thin-film capacitor bank unit and the supercapacitor bank unit are connected in parallel on a common DC bus in a frequency-division coordinated manner. The thin-film capacitor bank unit is used to suppress high-frequency ripple, and the supercapacitor bank unit is used for low-frequency energy buffering.

[0008] In some implementations of this application, both the thin-film capacitor bank unit and the supercapacitor bank unit have liquid-cooled cold plates integrated at their bottoms, and the liquid-cooled cold plates are connected to the external cooling circuit of the cabinet via quick-connect plugs.

[0009] In some implementations of this application, the pre-charge current limiting unit includes a bypass relay, a resistor barrel, and a delay control circuit. The two terminals of the resistor barrel are connected to the two main contact terminals of the bypass relay, and the two ends of the resistor barrel are also connected to the main circuit breaker and the DC output terminal, respectively. The output of the delay control circuit is connected to the control circuit of the bypass relay to control the bypass relay to conduct after a certain delay following power-on.

[0010] In some implementations of this application, the multi-machine rectifier interface module further includes a buffer circuit. One end of the buffer circuit is connected to the parallel input terminal, and the other end is connected to the common DC bus. Each parallel input terminal is connected to the output terminal of the corresponding wind turbine generator.

[0011] In some implementations of this application, the buffer circuit is an RC circuit or an RCD circuit.

[0012] In some implementations of this application, the integrated wind-hydrogen DC bus cabinet also includes a bidirectional AC / DC converter module, which is located in the rectifier unit area, with one end connected to the external AC power grid and the other end connected to the common DC bus.

[0013] In some implementations of this application, the bidirectional AC / DC converter module includes: an IGBT full-bridge power circuit, whose AC side is connected to the external AC power grid through an LCL filter, and whose DC side is connected to the common DC bus after being connected in parallel with a DC support capacitor bank; a main controller, which is connected to the IGBT full-bridge power circuit through a drive circuit; and voltage and current sensors, which are connected to the external AC power grid and the common DC bus, respectively, for acquiring signals and feeding them back to the main controller.

[0014] Secondly, this application provides a wind-hydrogen coupled power generation system, which includes multiple wind turbines, one or more electrolyzers, and at least one integrated wind-hydrogen DC bus cabinet as described in the first aspect, wherein the rectifier output terminals of the multiple wind turbines are connected to a multi-machine rectifier interface module, and the one or more electrolyzers are connected to the DC output terminals of the electrolyzer output module.

[0015] Compared with the prior art, this application has at least the following advantages or beneficial effects: This application provides an integrated DC bus cabinet for wind-to-hydrogen power generation. By reconfiguring the DC power supply system of wind-powered hydrogen production from both physical space and electrical connection dimensions, it enables multiple wind turbines to be connected in parallel to a low-impedance common DC bus via a multi-machine rectifier interface module, ensuring symmetry and consistency. Simultaneously, a buffer energy storage module is directly connected across both sides of the bus, providing a localized absorption and release path with extremely low impedance for high-frequency ripple and power fluctuations. This "shortest connection" and "local buffer" design significantly reduces the circulating current risk between parallel branches and minimizes energy loss. Furthermore, it can quickly smooth out voltage surges and ripples caused by wind turbine power fluctuations and switching operations, ensuring a more stable and pure DC power supply to the electrolyzer. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram showing the connection relationship between the internal modules of an embodiment of an integrated wind-hydrogen DC busbar cabinet according to this application; Figure 2 This is a schematic diagram showing the connection relationship between the internal modules of another embodiment of the integrated wind-hydrogen DC bus cabinet of this application; Figure 3 This is a schematic diagram of the pre-charge current limiting unit in one embodiment of an integrated wind-hydrogen DC bus switchgear according to this application; Figure 4 This is a schematic diagram showing the connection relationship between the internal modules of another embodiment of the integrated wind-hydrogen DC bus cabinet of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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 embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0020] Example: The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the various embodiments and features described below can be combined with each other.

[0021] In traditional wind power hydrogen production systems employing a series-connected distributed structure of "wind turbine generator - converter - rectifier cabinet - electrolyzer," circulating currents easily occur between rectifier branches when multiple generators are connected in parallel, leading to energy loss. Furthermore, excessive DC bus voltage ripple and frequent current surges often occur, severely impacting the electrolyzer's lifespan. Research by the inventors revealed that the primary reason for this is that the distributed layout makes impedance matching difficult, creating conditions for circulating currents. Additionally, parasitic parameters introduced by long-distance cables and the lack of energy storage units further exacerbate DC bus voltage fluctuations.

[0022] In response, this application's embodiments reconstruct the DC power supply system for wind-powered hydrogen production from both physical space and electrical connection dimensions through a highly integrated cabinet structure design, providing an integrated wind-hydrogen DC bus cabinet and a wind-hydrogen coupled power generation system, thereby effectively suppressing circulating current and DC bus ripple when multiple units are connected in parallel.

[0023] Please refer to Figure 1The integrated wind-hydrogen DC bus cabinet includes: a cabinet body, internally divided into a bus area, a rectifier unit area, a buffer energy storage area, and an output area; a common DC bus located in the bus area; a multi-generator rectifier interface module located in the rectifier unit area, including several parallel input terminals for connecting the outputs of multiple wind turbine generators to the common DC bus; a buffer energy storage module located in the buffer energy storage area and connected across both sides of the common DC bus for suppressing DC ripple; an electrolyzer output module located in the output area, including a main circuit breaker, a pre-charge current limiting unit, and a DC output terminal connected in series, with the end of the main circuit breaker furthest from the pre-charge current limiting unit connected to the common DC bus, and the end of the DC output terminal furthest from the pre-charge current limiting unit connected to an external electrolyzer; and a monitoring and protection unit located in the output area, electrically connected to the common DC bus, the multi-generator rectifier interface module, the buffer energy storage module, and the electrolyzer output module, respectively.

[0024] The reason why circulating current and ripple problems easily occur in other solutions is largely due to the inconsistent parameters of each branch in a distributed layout and the parasitic inductance and impedance introduced by long lines. However, in the above embodiment, by dividing the cabinet interior into a busbar area, rectifier unit area, buffer energy storage area, and output area, the originally distributed common DC busbar, multi-machine rectifier interface module, buffer energy storage module, electrolytic cell output module, and control and protection circuits can all be integrated into a single cabinet. Thus, each functional module achieves the shortest path electrical connection through the pre-installed common DC busbar within the cabinet. This not only fundamentally reduces equipment size and simplifies external wiring, but also effectively suppresses circulating current and bus voltage ripple through optimized internal layout and integrated buffer energy storage. Furthermore, the built-in monitoring and protection unit enables intelligent system management and safety isolation, ultimately improving system stability, reliability, and maintainability.

[0025] Specifically, in the above embodiment, multiple wind turbines are connected in parallel to a low-impedance common DC bus via a multi-machine rectifier interface module, ensuring symmetry and consistency. Simultaneously, a buffer energy storage module is directly connected across the bus, providing a localized absorption and release path with extremely low impedance for high-frequency ripple and power fluctuations. This "shortest connection" and "local buffering" design significantly reduces the risk of circulating currents between parallel branches and minimizes energy loss. Furthermore, it quickly smooths voltage spikes and ripples caused by wind turbine power fluctuations and switching actions, ensuring a more stable and pure DC power supply to the electrolyzer. This not only improves the overall operating efficiency of the integrated wind-hydrogen DC bus cabinet but also effectively extends the electrolyzer's lifespan. In addition, the pre-charge current limiting unit in the electrolyzer output module eliminates power-on surges, and the main circuit breaker provides short-circuit protection. Combined with the intelligent unit's rapid fault diagnosis and isolation capabilities, the overall stability of the integrated wind-hydrogen DC bus cabinet can be further enhanced.

[0026] In some implementations of this application, at least one of the multi-machine rectifier interface module, buffer energy storage module, and electrolytic cell output module is installed in the cabinet using a drawer-type structure, and the drawer-type structure includes a mechanical interlocking structure with the corresponding isolating circuit breaker or main circuit breaker.

[0027] In the above implementation, the multi-machine rectifier interface module, buffer energy storage module, and electrolytic cell output module are not fixed inside the cabinet, but are installed on dedicated guide rails like drawers. During maintenance, repair, or replacement, maintenance personnel can smoothly pull the entire functional module out of the cabinet, separating it from the main circuit, just like pulling out a desk drawer. This allows for comprehensive inspection, testing, or replacement without touching other components. Furthermore, the interlocking structure physically connects the drawer-type structure to its corresponding power switch—for the multi-machine rectifier interface module, it is its isolating circuit breaker; for the electrolytic cell output module, it is its main circuit breaker. This eliminates the extreme risk of maintenance personnel accidentally plugging or unplugging modules while the circuit is energized, providing a higher level of safety protection for operators and preventing damage to the electrical equipment caused by electric arcs from live plugging or unplugging.

[0028] Please refer to Figure 2 In some implementations of this application, the buffer energy storage module includes a thin-film capacitor bank unit and a supercapacitor bank unit. The thin-film capacitor bank unit and the supercapacitor bank unit are connected in parallel on a common DC bus in a frequency-division coordination manner. The thin-film capacitor bank unit is used to suppress high-frequency ripple, and the supercapacitor bank unit is used for low-frequency energy buffering.

[0029] In the above implementation, the thin-film capacitor bank unit is characterized by its extremely low equivalent series resistance, meaning it has very low impedance to high-frequency currents, resulting in extremely fast charging and discharging response speeds (down to the microsecond level), but with relatively less stored total energy. The supercapacitor bank unit, on the other hand, is characterized by its very large capacitance, enabling it to store and release large amounts of energy. Its response speed is faster (millisecond level), but slightly slower than the thin-film capacitor bank unit. Thus, the high-frequency pulsating current generated by the high-speed switching of power electronic devices (such as IGBTs) will automatically select the path of lowest impedance due to its high-frequency characteristics. In this case, the thin-film capacitor bank unit will be specifically responsible for suppressing high-frequency ripple and purifying the DC power. Power fluctuations caused by wind speed changes have a lower frequency but higher energy; the supercapacitor bank unit can absorb or release this low-frequency fluctuation energy, thereby smoothing macroscopic changes in the bus voltage. In other words, this structure, where the thin-film capacitor bank unit and the supercapacitor bank unit cooperate according to the frequency characteristics of current or power fluctuations and are connected in parallel on a common DC bus, greatly improves the operational stability of the entire integrated hydrogen DC bus cabinet.

[0030] In some implementations of this application, both the thin-film capacitor bank unit and the supercapacitor bank unit have liquid-cooled cold plates integrated at their bottoms, and the liquid-cooled cold plates are connected to the external cooling circuit of the cabinet via quick-connect plugs.

[0031] Since thin-film capacitor banks and supercapacitor banks generate a lot of heat due to their internal equivalent resistance when processing high-frequency ripple and buffering large current energy, in the above implementation, by integrating a liquid cooling plate at the bottom of the thin-film capacitor bank and supercapacitor bank, the heat generated by the thin-film capacitor bank and supercapacitor bank during operation can be directly and efficiently transferred to the coolant flowing inside the cooling plate through conduction, thereby improving their working performance.

[0032] Please refer to Figure 3 In some implementations of this application, the pre-charge current limiting unit includes a bypass relay, a resistor barrel, and a delay control circuit. The two terminals of the resistor barrel are connected to the two main contact terminals of the bypass relay, and the two ends of the resistor barrel are also connected to the main circuit breaker and the DC output terminal, respectively. The output of the delay control circuit is connected to the control circuit of the bypass relay to control the bypass relay to conduct after a certain delay following power-on.

[0033] In the above implementation, during the initial power-on phase of the integrated wind-hydrogen DC bus switchgear, the main circuit breaker closes, while the bypass relay remains open. Current is forced to flow through the resistor tank, using resistance to limit the inrush current and pre-charge the downstream capacitive loads (such as bus capacitors, electrolytic cells, and their wiring). During this process, the delay control circuit begins timing. When pre-charging is complete, the bus voltage stabilizes, and after the preset delay is reached, the delay control circuit automatically triggers, driving the bypass relay to engage and close its main contacts, thereby short-circuiting the resistor tank. The integrated wind-hydrogen DC bus switchgear then transitions to a low-impedance, full-power operation state. In other words, the pre-charge current limiting unit, by integrating the bypass relay, resistor tank, and delay control circuit, can limit the bus charging current during the initial power-on phase to prevent surges; after the delay, it automatically switches to low-impedance bypass operation, ensuring a smooth start-up of the integrated hydrogen DC bus switchgear.

[0034] In some implementations of this application, the multi-machine rectifier interface module further includes a buffer circuit. One end of the buffer circuit is connected to the parallel input terminal, and the other end is connected to the common DC bus. Each parallel input terminal is connected to the output terminal of the corresponding wind turbine generator.

[0035] In the above implementation, a buffer circuit is further added to each wind power input branch within the multi-machine rectifier interface module. The function of this buffer circuit is to suppress voltage spikes and high-frequency oscillations generated during the switching process of power electronic devices. When the wind turbine-side converter or the rectifier unit in the cabinet switches, the parasitic inductance and capacitance of the line will form a high-frequency resonance, generating a spike voltage much higher than the normal operating voltage at the moment of disconnection. By providing a controllable discharge path, the buffer circuit can quickly absorb these instantaneous overvoltage energies and convert them into heat energy for dissipation or smooth release to the DC bus.

[0036] For example, the snubber circuit can be an RC circuit or an RCD circuit. An RC snubber circuit consists of a resistor and a capacitor connected in series. Its working principle is to absorb the voltage spike generated when the switching transistor is turned off by utilizing the characteristic that the capacitor voltage cannot change abruptly. The absorbed energy is then dissipated as heat through the resistor. This circuit structure is simple and low-cost, suitable for low-to-medium power applications. An RCD snubber circuit adds a diode to the RC circuit, forming a combination of resistor, capacitor, and parallel diode. The diode provides a fast charging path, allowing the capacitor to more effectively limit the voltage rise rate, while the resistor controls the discharge process. This structure can more effectively suppress voltage overshoot and is suitable for high-frequency, high-current applications.

[0037] Please refer to Figure 4 In some implementations of this application, the integrated wind-hydrogen DC bus cabinet also includes a bidirectional AC / DC converter module. The bidirectional AC / DC converter module is located in the rectifier unit area, with one end connected to the external AC power grid and the other end connected to the common DC bus.

[0038] In the aforementioned implementation, by integrating a bidirectional AC / DC converter module into the integrated wind-hydrogen DC bus cabinet, it can be upgraded from a simple wind-powered hydrogen production device into a flexible interconnected device with grid connection support capabilities. This not only improves wind power absorption capacity but also enhances the overall system benefits by participating in grid services. Specifically, when wind power is surplus, the bidirectional AC / DC converter module operates in inverter mode, converting excess DC power into AC power to feed into the grid, significantly reducing wind curtailment. When wind power is insufficient, it can operate in rectification mode, drawing power from the grid to supplement the energy of the electrolyzer and maintain the continuity of hydrogen production. Furthermore, this bidirectional AC / DC converter module can operate in reactive power compensation mode, dynamically adjusting reactive power when not transmitting active power, actively supporting grid voltage stability.

[0039] In some implementations of this application, the bidirectional AC / DC converter module includes: an IGBT full-bridge power circuit, whose AC side is connected to the external AC power grid through an LCL filter, and whose DC side is connected to the common DC bus after being connected in parallel with a DC support capacitor bank; a main controller, which is connected to the IGBT full-bridge power circuit through a drive circuit; and voltage and current sensors, which are connected to the external AC power grid and the common DC bus, respectively, for acquiring signals and feeding them back to the main controller.

[0040] In the above implementation, the IGBT full-bridge power circuit performs AC / DC conversion. On the AC side, an LCL filter is connected to the grid to effectively suppress switching harmonics and ensure grid-connected power quality. On the DC side, a DC support capacitor bank is connected in parallel to the common DC bus, providing a stable DC voltage platform and instantaneous energy buffer for the power devices. The main controller precisely controls the switching state of the IGBTs through a drive circuit, while voltage and current sensors distributed on the grid side and the DC bus collect system parameters in real time and feed them back to the controller, forming a closed-loop control. In summary, this implementation ensures system stability during bidirectional energy flow through the synergistic effect of the LCL filter and the DC support capacitor, meeting grid-connected harmonic standards while suppressing bus voltage fluctuations.

[0041] This application also proposes a wind-hydrogen coupled power generation system, which includes multiple wind turbines, one or more electrolyzers, and at least one integrated wind-hydrogen DC bus cabinet as described in the first aspect. The rectifier output terminals of the multiple wind turbines are connected to a multi-machine rectifier interface module, and the one or more electrolyzers are connected to the DC output terminals of the electrolyzer output module.

[0042] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A wind-hydrogen DC bus integrated cabinet, characterized in that, include: The cabinet is internally divided into a busbar area, a rectifier unit area, a buffer energy storage area, and an output area. A common DC bus is located in the busbar area; A multi-machine rectifier interface module is located in the rectifier unit area and includes several parallel input terminals for connecting the outputs of multiple wind turbine generators to the common DC bus. A buffer energy storage module is located in the buffer energy storage area and is connected across both sides of the common DC bus to suppress DC ripple. An electrolytic cell output module, located in the output area, includes a main circuit breaker, a pre-charge current limiting unit, and a DC output terminal connected in series. The end of the main circuit breaker away from the pre-charge current limiting unit is connected to the common DC bus, and the end of the DC output terminal away from the pre-charge current limiting unit is used to connect to an external electrolytic cell. The monitoring and protection unit is located in the output area and is electrically connected to the common DC bus, the multi-machine rectifier interface module, the buffer energy storage module and the electrolytic cell output module, respectively.

2. The integrated wind-hydrogen DC bus switchgear according to claim 1, characterized in that, At least one of the multi-machine rectifier interface module, buffer energy storage module and electrolytic cell output module is installed in the cabinet with a drawer-type structure, and the drawer-type structure includes a mechanical interlocking structure with the corresponding isolating circuit breaker or main circuit breaker.

3. The integrated wind-hydrogen DC bus switchgear according to claim 1, characterized in that, The buffer energy storage module includes a thin-film capacitor bank unit and a supercapacitor bank unit. The thin-film capacitor bank unit and the supercapacitor bank unit are connected in parallel on the common DC bus in a frequency-division coordinated manner. The thin-film capacitor bank unit is used to suppress high-frequency ripple, and the supercapacitor bank unit is used for low-frequency energy buffering.

4. The integrated wind-hydrogen DC bus switchgear according to claim 3, characterized in that, Both the thin-film capacitor bank unit and the supercapacitor bank unit have liquid-cooled plates integrated at their bottoms, and the liquid-cooled plates are connected to the external cooling circuit of the cabinet via quick-connect plugs.

5. The integrated wind-hydrogen DC bus switchgear according to claim 1, characterized in that, The precharge current limiting unit includes a bypass relay, a resistor bucket, and a delay control circuit. The two terminals of the resistor barrel are respectively connected to the two main contact terminals of the bypass relay. The two ends of the resistor barrel are also respectively connected to the main circuit breaker and the DC output terminal. The output terminal of the delay control circuit is connected to the control circuit of the bypass relay to control the bypass relay to conduct after a certain delay after power-on.

6. The integrated wind-hydrogen DC bus switchgear according to claim 1, characterized in that, The multi-machine rectifier interface module also includes a buffer circuit. One end of the buffer circuit is connected to the parallel input terminal, and the other end is connected to the common DC bus. Each of the parallel input terminals is connected to the output terminal of the corresponding wind turbine generator.

7. The integrated wind-hydrogen DC bus switchgear according to claim 6, characterized in that, The buffer circuit is an RC circuit or an RCD circuit.

8. The integrated wind-hydrogen DC bus switchgear according to claim 1, characterized in that, It also includes a bidirectional AC / DC converter module, which is located in the rectifier unit area, with one end connected to the external AC power grid and the other end connected to the common DC bus.

9. The integrated wind-hydrogen DC bus switchgear according to claim 8, characterized in that, The bidirectional AC / DC converter module includes: The IGBT full-bridge power circuit has its AC side connected to the external AC power grid through an LCL filter, and its DC side is connected to the common DC bus after being connected in parallel with a DC support capacitor bank. The main controller is connected to the IGBT full-bridge power circuit via a drive circuit; Voltage and current sensors are connected to the external AC power grid and the common DC bus, respectively, to collect signals and feed them back to the main controller.

10. A wind-hydrogen coupled power generation system, characterized in that, The device includes multiple wind turbines, one or more electrolyzers, and at least one integrated wind-hydrogen DC bus cabinet as described in any one of claims 1 to 9, wherein the rectifier output terminals of the multiple wind turbines are connected to a multi-machine rectifier interface module, and the one or more electrolyzers are connected to the DC output terminals of the electrolyzer output module.

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