Efficient light storage hydrogen production alternating current and direct current micro-grid control system and control method

Abstract

The invention discloses an efficient light storage hydrogen production alternating current and direct current micro-grid control system and method. The system comprises a light storage hydrogen production alternating current and direct current micro-grid control unit, an inversion rectification conversion unit, an alternating current hydrogen production power supply, a photovoltaic power generation unit, a battery energy storage unit and a direct current hydrogen production power supply. A switch S1 is arranged between the inversion rectification conversion unit and the light storage hydrogen production AC / DC micro-grid control unit; the alternating-current hydrogen production power supply is used for alternating-current electrolytic hydrogen production; the photovoltaic power generation unit is used for supplying power for photovoltaic power generation conversion; the battery energy storage unit is used for charging and discharging the battery; and the direct-current hydrogen production power supply is used for direct-current electrolysis hydrogen production and hydrogen storage. The invention provides a high-efficiency alternating current and direct current micro-grid system capable of adapting to different hydrogen production equipment and photovoltaic energy storage matching complementation and a control method, the system can provide energy hydrogen production and hydrogen storage for the existing alternating current hydrogen production equipment and direct current hydrogen production equipment, and grid-connected power generation and independent power generation can be realized; and the system can realize photovoltaic energy storage hydrogen production nearby.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic hydrogen production control, and in particular to an efficient photovoltaic hydrogen production AC / DC microgrid control system and control method. Background Art

[0002] As the global demand for clean energy grows, photovoltaic hydrogen production has gradually attracted attention as a highly promising energy storage and energy conversion technology. Photovoltaic systems use solar energy to generate electricity, and the generated electricity is converted into hydrogen through the power supply of hydrogen production equipment to the electrolyzer for storage, thus realizing the allocation of energy across time periods and forms. However, the current photovoltaic hydrogen production system has many control difficulties, including the intermittent and volatile nature of solar energy, which leads to unstable photovoltaic output power, making it difficult to maintain an efficient and stable operating condition during the water electrolysis hydrogen production process; at the same time, the coordination between the various components is not smart enough, which can easily lead to energy waste and increased equipment loss. In addition, when transmitting electricity between two distant regions through photovoltaic power generation, the lines are too long and the losses are huge.

[0003] Therefore, this scheme proposes an efficient photovoltaic hydrogen production AC / DC microgrid control system and control method to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide an efficient photovoltaic hydrogen production AC / DC microgrid control system and control method to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solutions: an efficient photovoltaic hydrogen storage AC / DC microgrid control system, the control system comprising a photovoltaic hydrogen storage AC / DC microgrid control unit, an inverter rectifier conversion unit, an AC hydrogen production power supply, a photovoltaic power generation unit, a battery energy storage unit and a DC hydrogen production power supply; The photovoltaic hydrogen production AC / DC microgrid control unit is used for switch control and energy scheduling of the system; A switch S1 is provided between the inverter-rectifier conversion unit and the photovoltaic hydrogen production AC / DC microgrid control unit, and the inverter-rectifier conversion unit is used for on-grid and off-grid operation through the switch S1; The AC hydrogen production power supply is used to perform AC electrolysis to produce hydrogen and store hydrogen in the electrolyzer; The photovoltaic power generation unit is used for power supply of photovoltaic power generation conversion; The battery energy storage unit is used to charge and discharge the battery; The DC hydrogen production power supply is used to perform DC electrolysis to produce hydrogen and store hydrogen in the electrolyzer.

[0006] Preferably, the control system also includes a DC bus 750VDC and a grid AC 380VAC.

[0007] Preferably, the inverter-rectifier conversion unit adopts a bidirectional DC / AC, and the bidirectional DC / AC is used to invert the grid AC power 380VAC through the DC bus 750VDC, and the bidirectional DC / AC is also used to rectify the grid AC power 380VAC into a DC voltage of 750VDC.

[0008] Preferably, the input end of the AC hydrogen production power supply is used to input 380V AC power, and the output end of the AC hydrogen production power supply is used to output DC power.

[0009] Preferably, the photovoltaic power generation unit adopts a DC / DC boost circuit for boosting the voltage to a 750VDC busbar.

[0010] Preferably, the DC bus 750VDC is electrically connected to the battery through a battery energy storage unit.

[0011] Preferably, the input end of the DC hydrogen production power supply is used to input 750V DC power, and the output end of the DC hydrogen production power supply is used to output DC power.

[0012] A control method for an efficient photovoltaic hydrogen production AC / DC microgrid control system, using the control system, wherein the control method comprises the following steps when the grid is powered: The inverter rectifier conversion unit and the photovoltaic power generation unit generate electricity. At this time, the bus 750VDC outputs electric energy to the DC hydrogen production power supply for electrolytic hydrogen production, and the bus 750VDC controls the grid-connected switch S1 to be closed through the inverter rectifier conversion unit to connect to the grid 380VAC. At this time, the electric energy generated by the photovoltaic power generation unit is used to produce hydrogen and store hydrogen after passing through the AC hydrogen production power supply; AC hydrogen production power supply, when the hydrogen production and storage capacity is full, the electricity generated by the photovoltaic power generation unit is used to charge and store the battery through the battery energy storage unit, and after the battery is fully charged, the electricity generated by the photovoltaic power generation unit is connected to the grid and fed back to the grid; Photovoltaic power generation unit, when the electricity generated by the photovoltaic power generation unit is not enough to provide hydrogen production equipment for hydrogen production and storage, the battery outputs electricity through the battery energy storage unit and the electricity generated by the battery energy storage unit is first aggregated to the bus 750VDC, and the aggregated electricity passes through the DC hydrogen production power supply, the inverter rectifier conversion unit, the switch S1 and the AC hydrogen production power supply in turn, and finally to the electrolyzer for hydrogen production and storage; Battery energy storage unit. When the energy generated by both the photovoltaic power generation unit and the battery energy storage unit is insufficient, part of the power from the power grid is used to produce hydrogen for the electrolyzer through the AC hydrogen production power supply, and the other part is first generated through the switch S1 and the inverter rectifier conversion unit to generate a bus 750VDC, and then through the DC bus bus. After being aggregated, the battery is charged through the battery energy storage unit and the electrolyzer is electrolyzed and produced hydrogen through the DC hydrogen production power supply to produce DC hydrogen.

[0013] Preferably, the control method comprises the following steps of preparation operations when the power grid fails or loses power: B1, the photovoltaic power generation unit outputs electric energy, and the output electric energy is first provided to the hydrogen production equipment for hydrogen production and storage in the electrolyzer, and then provided to the battery energy storage unit for battery charging; B2, when the photovoltaic power generation unit is short of power, it cooperates with the battery energy storage unit to output the power of the battery, and the power is combined and provided to the hydrogen production equipment for hydrogen production and storage in the electrolyzer; B3. When the electric energy provided by the photovoltaic power generation unit and the battery is less than the power required for hydrogen production, the output electrolysis parameters of the AC hydrogen production power supply and the DC hydrogen production power supply are adjusted to reduce the output current and voltage of the hydrogen electrolysis of the hydrogen production power supply, thereby reducing the hydrogen production rate.

[0014] Preferably, when the hydrogen production rate needs to be increased, the AC hydrogen production power supply is turned off, the AC power of the power grid is aggregated to a bus of 750V through switch S1 and the inverter rectifier conversion unit, and then electrolysis is performed by the DC hydrogen production power supply. Thereafter, the hydrogen production rate is increased by increasing the output current and voltage of the DC hydrogen production power supply.

[0015] Technical effects and advantages of the present invention: The present invention proposes an efficient AC / DC microgrid system and a control method that can adapt to different hydrogen production equipment and complementary photovoltaic energy storage. The system can provide energy for hydrogen production and storage to existing AC hydrogen production equipment and DC hydrogen production equipment, and can realize grid-connected power generation, and can also generate electricity independently; and the system can realize photovoltaic energy storage and hydrogen production nearby, and the excess photovoltaic energy can be stored for hydrogen production and storage, which is energy-friendly and environmentally friendly and reduces transportation losses; the system realizes high-efficiency power control, realizes the maximum power output of photovoltaic panels, ensures the high efficiency of hydrogen production utilization, adjusts the output power according to weather conditions, changes the electrolysis parameters, and maintains the stability of the hydrogen production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the system composition of the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Embodiment 1, the present invention provides as follows Figure 1An efficient photovoltaic hydrogen storage AC / DC microgrid control system shown includes a photovoltaic hydrogen storage AC / DC microgrid control unit, an inverter rectifier conversion unit, an AC hydrogen production power supply, a photovoltaic power generation unit, a battery energy storage unit, a DC bus 750VDC, a grid AC 380VAC and a DC hydrogen production power supply; The photovoltaic hydrogen production AC / DC microgrid control unit is used for the system's switch control and energy scheduling; It should be noted that the photovoltaic storage and hydrogen production AC / DC microgrid control unit controls and dispatches the sub-generation systems, energy systems and switches in the system.

[0019] A switch S1 is provided between the inverter-rectifier conversion unit and the photovoltaic hydrogen production AC / DC microgrid control unit, and the inverter-rectifier conversion unit is used for on-grid and off-grid operation through the switch S1; Specifically, the inverter-rectifier conversion unit adopts a bidirectional DC / AC, and the bidirectional DC / AC is used to invert the grid AC power 380VAC through the DC bus 750VDC, and the bidirectional DC / AC is also used to rectify the grid AC power 380VAC into a DC voltage of 750VDC.

[0020] It should be noted that the inverter-rectifier conversion unit is actually a bidirectional DCAC, which can invert the grid AC power 380VAC through the DC bus 750VDC. The 380VAC can also be rectified into a DC voltage of 750VDC, which can be used with the S1 switch for on-grid and off-grid operations.

[0021] The AC hydrogen production power supply is used to supply the electrolyzer with AC electrolysis to produce hydrogen and store hydrogen; Specifically, the input end of the AC hydrogen production power supply is used to input 380V AC power, and the output end of the AC hydrogen production power supply is used to output DC power.

[0022] The photovoltaic power generation unit is used for power supply of photovoltaic power generation conversion; Specifically, the photovoltaic power generation unit adopts a DC / DC boost circuit to boost the voltage to a 750VDC bus.

[0023] It should be noted that the photovoltaic power generation unit has the MPPT maximum power point tracking function to improve the photovoltaic power generation conversion efficiency. The hardware is a DCDC boost circuit that boosts the voltage to a 750VDC aggregate bus.

[0024] Battery energy storage units are used to charge and discharge batteries Specifically, the DC bus 750VDC is electrically connected to the battery through the battery energy storage unit.

[0025] It should be noted that the battery energy storage unit provides power through the battery energy storage unit's bidirectional DCDC DC conversion to the bus 750VDC, and the bus 750VDC can also charge the battery through the battery energy storage unit.

[0026] The DC hydrogen production power supply is used to supply the electrolyzer with DC electrolysis to produce hydrogen and store hydrogen.

[0027] Specifically, the input end of the DC hydrogen production power supply is used to input 750V DC power, and the output end of the DC hydrogen production power supply is used to output DC power.

[0028] It should be noted that the DC hydrogen production power input is a DC 750V input, and the output is low-voltage DC power, which is used to electrolyze and store hydrogen in the electrolyzer.

[0029] In the second embodiment, the present invention provides a control method for an efficient photovoltaic hydrogen production AC / DC microgrid control system, using the control system of the first embodiment. When the grid is powered, the control method includes the following steps: The inverter rectifier conversion unit and the photovoltaic power generation unit generate electricity. At this time, the bus 750VDC outputs electric energy to the DC hydrogen production power supply for electrolytic hydrogen production, and the bus 750VDC controls the grid-connected switch S1 to be closed through the inverter rectifier conversion unit to connect to the grid 380VAC. At this time, the electric energy generated by the photovoltaic power generation unit is used to produce hydrogen and store hydrogen after passing through the AC hydrogen production power supply; AC hydrogen production power supply, when the hydrogen production and storage capacity is full, the electricity generated by the photovoltaic power generation unit is used to charge and store the battery through the battery energy storage unit, and after the battery is fully charged, the electricity generated by the photovoltaic power generation unit is connected to the grid and fed back to the grid; Photovoltaic power generation unit, when the electricity generated by the photovoltaic power generation unit is not enough to provide hydrogen production equipment for hydrogen production and storage, the battery outputs electricity through the battery energy storage unit and the electricity generated by the battery energy storage unit is first aggregated to the bus 750VDC, and the aggregated electricity passes through the DC hydrogen production power supply, the inverter rectifier conversion unit, the switch S1 and the AC hydrogen production power supply in turn, and finally to the electrolyzer for hydrogen production and storage; Battery energy storage unit. When the energy generated by both the photovoltaic power generation unit and the battery energy storage unit is insufficient, part of the power from the power grid is used to produce hydrogen for the electrolyzer through the AC hydrogen production power supply, and the other part is first generated through the switch S1 and the inverter rectifier conversion unit to generate a bus 750VDC, and then through the DC bus bus. After being aggregated, the battery is charged through the battery energy storage unit and the electrolyzer is electrolyzed and produced hydrogen through the DC hydrogen production power supply to produce DC hydrogen.

[0030] It should be noted that when the grid has electricity: 1) When the photovoltaic power generation is sufficient and meets all the requirements of hydrogen production power: In order to obtain the maximum power output, the photovoltaic power generation unit needs to be controlled by MPPT to output the maximum power to the bus 750VDC. The output electric energy is mainly used for electrolysis of hydrogen by the DC hydrogen production power supply, and the bus 750VDC controls the grid-connected and off-grid switch S1 to close through the inverter rectifier conversion unit to achieve grid connection 380VAC. At this time, the electricity generated by the photovoltaic power supply is mainly used to produce hydrogen and store hydrogen after passing through the AC hydrogen production power supply.

[0031] 2) When the hydrogen production and storage capacity is full, that is, no more hydrogen production and storage is needed, the excess energy generated by photovoltaic power generation can flow bidirectionally through the battery energy storage unit to charge the battery and store energy, and store the excess electricity for backup. If the battery is fully charged and there is still photovoltaic energy left, it can be connected to the grid and fed back to the grid.

[0032] 3) When it is rainy or cloudy, the energy generated by photovoltaics is not enough to provide hydrogen production equipment for hydrogen production and storage. At this time, energy storage is needed. The energy generated by the battery energy storage unit and the electric energy generated by the photovoltaic power generation unit are aggregated to the bus 750VDC, and finally supplied to the electrolyzer for hydrogen production and storage through the DC hydrogen production power supply and inverter rectifier conversion unit, switch S1 and AC hydrogen production power supply.

[0033] 4) When the energy generated by both photovoltaics and energy storage is insufficient to provide energy for the hydrogen production equipment, the grid has electricity and participates in the process. On the one hand, the AC hydrogen production power supply is used to produce hydrogen for the electrolyzer to meet the hydrogen production and storage needs on the AC side. On the other hand, the switch S1 and the inverter rectifier conversion unit generate a bus 750VDC, which is then connected to the DC bus to charge the battery through the battery energy storage unit and to produce hydrogen for the electrolyzer through the DC hydrogen production power supply, meeting the hydrogen production needs on the DC side.

[0034] Furthermore, the control method includes the following steps of preparation operations when the power grid fails or loses power: B1, the photovoltaic power generation unit outputs electric energy, and the output electric energy is first provided to the hydrogen production equipment for hydrogen production and storage in the electrolyzer, and then provided to the battery energy storage unit for battery charging; B2, when the photovoltaic power generation unit is short of power, it cooperates with the battery energy storage unit to output the power of the battery, and the power is combined and provided to the hydrogen production equipment for hydrogen production and storage in the electrolyzer; B3. When the electric energy provided by the photovoltaic power generation unit and the battery is less than the power required for hydrogen production, the output electrolysis parameters of the AC hydrogen production power supply and the DC hydrogen production power supply are adjusted to reduce the output current and voltage of the hydrogen electrolysis of the hydrogen production power supply, thereby reducing the hydrogen production rate.

[0035] It should be noted that when the power grid fails or loses power: 1) When the photovoltaic power generation is sufficient and meets the power required by all hydrogen production and storage capacities, energy is provided to the hydrogen production equipment first for hydrogen production and storage in the electrolyzer, and the excess energy is used to charge the battery for energy storage; 2) When the photovoltaic power generation power does not meet the hydrogen production power requirements of the hydrogen production equipment, it can be used together with the energy storage system to provide energy to the hydrogen production equipment; 3) When the power generated by photovoltaics and batteries is less than the power required for hydrogen production, in order to ensure the stability and reliability of the hydrogen production process, it is necessary to adjust the electrolysis parameters of the DC hydrogen production power supply and the AC hydrogen production power supply, that is, adjust the output electrolysis parameters of the AC hydrogen production power supply and the DC hydrogen production power supply, and give priority to reducing the output current and voltage of the hydrogen production power supply for electrolysis of hydrogen in the case of insufficient input power, reducing the hydrogen production rate, and smoothing hydrogen production.

[0036] Furthermore, when the hydrogen production rate needs to be increased, the AC hydrogen production power supply is turned off, the AC power of the grid is aggregated to a bus of 750V through switch S1 and the inverter rectifier conversion unit, and then electrolyzed by the DC hydrogen production power supply. After that, the hydrogen production rate is increased by increasing the output current and voltage of the DC hydrogen production power supply.

[0037] It should be noted that when efficient hydrogen production is required: Based on the principle of minimizing multi-stage power conversion (DCDC), the AC hydrogen production power supply can be turned off to prevent it from working. After all the energy of the AC power of the power grid is aggregated to 750V through the switch S1 and the inverter rectifier conversion unit, it is directly supplied to the electrolyzer through the DC hydrogen production power supply. When the external electrolytic hydrogen production capacity is large and the hydrogen production rate needs to be increased, the output current and voltage of the DC hydrogen production power supply can be increased to directly and efficiently increase the hydrogen production rate. This method reduces the AC hydrogen production power supply. The AC hydrogen production power supply, as an AC hydrogen production power supply, includes two-level topologies of AC / DC and DC / DC. The grid> switch S1-> inverter rectifier conversion unit-> 750VDC-> DC hydrogen production power supply-> electrolyzer is actually equivalent to the topological path of the AC hydrogen production power supply.

[0038] The system incorporates AC hydrogen production power supply to ensure multiple paths for hydrogen production. Whether it is AC or DC hydrogen production, it should meet the function of photovoltaic and off-grid hydrogen production.

[0039] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An efficient AC / DC microgrid control system for photovoltaic hydrogen production, characterized in that: The control system includes a photovoltaic storage hydrogen production AC / DC microgrid control unit, an inverter rectifier conversion unit, an AC hydrogen production power supply, a photovoltaic power generation unit, a battery energy storage unit and a DC hydrogen production power supply; The photovoltaic hydrogen production AC / DC microgrid control unit is used for switch control and energy scheduling of the system; A switch S1 is provided between the inverter-rectifier conversion unit and the photovoltaic hydrogen production AC / DC microgrid control unit, and the inverter-rectifier conversion unit is used for on-grid and off-grid operation through the switch S1; The AC hydrogen production power supply is used to perform AC electrolysis to produce hydrogen and store hydrogen in the electrolyzer; The photovoltaic power generation unit is used for power supply of photovoltaic power generation conversion; The battery energy storage unit is used to charge and discharge the battery; The DC hydrogen production power supply is used to perform DC electrolysis to produce hydrogen and store hydrogen in the electrolyzer.

2. According to claim 1, a highly efficient AC / DC microgrid control system for photovoltaic hydrogen production is characterized in that: The control system also includes a DC bus 750VDC and a grid AC 380VAC.

3. According to claim 2, a highly efficient AC / DC microgrid control system for photovoltaic hydrogen production is characterized in that: The inverter-rectifier conversion unit adopts a bidirectional DC / AC, and the bidirectional DC / AC is used to invert the grid AC power 380VAC through the DC bus 750VDC, and the bidirectional DC / AC is also used to rectify the grid AC power 380VAC into a DC voltage of 750VDC.

4. According to claim 1, a highly efficient AC / DC microgrid control system for photovoltaic hydrogen production is characterized in that: The input end of the AC hydrogen production power supply is used to input 380V AC power, and the output end of the AC hydrogen production power supply is used to output DC power.

5. According to claim 2, a highly efficient photovoltaic hydrogen production AC / DC microgrid control system is characterized in that: The photovoltaic power generation unit adopts a DC / DC boost circuit for boosting the voltage to a 750VDC busbar.

6. According to claim 2, a highly efficient AC / DC microgrid control system for photovoltaic hydrogen production is characterized in that: The DC bus 750VDC is electrically connected to the battery through the battery energy storage unit.

7. According to claim 1, a highly efficient photovoltaic hydrogen production AC / DC microgrid control system is characterized in that: The input end of the DC hydrogen production power supply is used to input 750V DC power, and the output end of the DC hydrogen production power supply is used to output DC power.

8. A control method for an efficient photovoltaic hydrogen production AC / DC microgrid control system, using a control system according to any one of claims 1 to 7, characterized in that: When the power grid is powered, the control method comprises the following steps: The inverter rectifier conversion unit and the photovoltaic power generation unit generate electricity. At this time, the bus 750VDC outputs electric energy to the DC hydrogen production power supply for electrolytic hydrogen production, and the bus 750VDC controls the grid-connected switch S1 to be closed through the inverter rectifier conversion unit to connect to the grid 380VAC. At this time, the electric energy generated by the photovoltaic power generation unit is used to produce hydrogen and store hydrogen after passing through the AC hydrogen production power supply; AC hydrogen production power supply, when the hydrogen production and storage capacity is full, the electricity generated by the photovoltaic power generation unit is used to charge and store the battery through the battery energy storage unit, and after the battery is fully charged, the electricity generated by the photovoltaic power generation unit is connected to the grid and fed back to the grid; Photovoltaic power generation unit, when the electricity generated by the photovoltaic power generation unit is not enough to provide hydrogen production equipment for hydrogen production and storage, the battery outputs electricity through the battery energy storage unit and the electricity generated by the battery energy storage unit is first aggregated to the bus 750VDC, and the aggregated electricity passes through the DC hydrogen production power supply, the inverter rectifier conversion unit, the switch S1 and the AC hydrogen production power supply in turn, and finally to the electrolyzer for hydrogen production and storage; Battery energy storage unit. When the energy generated by both the photovoltaic power generation unit and the battery energy storage unit is insufficient, part of the power from the power grid is used to produce hydrogen for the electrolyzer through the AC hydrogen production power supply, and the other part is first generated through the switch S1 and the inverter rectifier conversion unit to generate a bus 750VDC, and then through the DC bus bus. After being aggregated, the battery is charged through the battery energy storage unit and the electrolyzer is electrolyzed and produced hydrogen through the DC hydrogen production power supply to produce DC hydrogen.

9. The control method of a highly efficient photovoltaic hydrogen production AC / DC microgrid control system according to claim 8 is characterized in that: The control method comprises the following steps of preparation and operation when the power grid fails or loses power: B1, the photovoltaic power generation unit outputs electric energy, and the output electric energy is first provided to the hydrogen production equipment for hydrogen production and storage in the electrolyzer, and then provided to the battery energy storage unit for battery charging; B2, when the photovoltaic power generation unit is short of power, it cooperates with the battery energy storage unit to output the power of the battery, and the power is combined and provided to the hydrogen production equipment for hydrogen production and storage in the electrolyzer; B3. When the electric energy provided by the photovoltaic power generation unit and the battery is less than the power required for hydrogen production, the output electrolysis parameters of the AC hydrogen production power supply and the DC hydrogen production power supply are adjusted to reduce the output current and voltage of the hydrogen electrolysis of the hydrogen production power supply, thereby reducing the hydrogen production rate.

10. The control method of a highly efficient photovoltaic hydrogen production AC / DC microgrid control system according to claim 9 is characterized in that: When the hydrogen production rate needs to be increased, the AC hydrogen production power supply is turned off, the AC power of the power grid is aggregated to a bus of 750V through the switch S1 and the inverter rectifier conversion unit, and then electrolysis is performed by the DC hydrogen production power supply. After that, the hydrogen production rate is increased by increasing the output current and voltage of the DC hydrogen production power supply.

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