Photovoltaic coupling hydrogen production power supply device, system and control method

Abstract

The invention discloses a photovoltaic coupling hydrogen production power supply device and system and a control method thereof.The device comprises a first power supply module and a second power supply module, the input end of the first power supply module is connected with a direct-current bus of a photovoltaic system, and the output end of the first power supply module is connected with a hydrogen production electrolytic bath; the input end of the first power module is further connected with an energy storage system or a power generation system through the second power module, and the first power module is used for being connected with direct current provided by a direct current bus of a photovoltaic system to conduct direct current conversion so as to supply energy to a hydrogen production electrolytic cell. And the second power supply module is used for converting the electric energy accessed to the energy storage system or the power generation system so as to provide supplementary direct current electric energy for the first power supply module, or returning the redundant electric energy output by the accessed photovoltaic system to the energy storage system or the power generation system. The system has the advantages of being simple in structure, low in cost, high in stability and efficiency, low in control complexity, high in flexibility and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production power supply, and in particular to a photovoltaic coupled hydrogen production power supply device, system and control method. Background Art

[0002] Hydrogen energy is not only a clean, carbon-free, and richly applicable secondary energy source, but also an important industrial raw material. Converting new energy electricity into hydrogen energy through a hydrogen production device is an ideal way to consume new energy. Photovoltaic system DC-coupled hydrogen production is to directly connect the electricity output by the photovoltaic system to the hydrogen production power source, which can not only effectively consume new energy, but also eliminate the need for an intermediate converter in photovoltaic system DC-coupled hydrogen production, thus achieving efficient use of electricity.

[0003] In the prior art, direct current coupled hydrogen production in photovoltaic systems usually uses a photovoltaic single-stage hydrogen production power supply, that is, the photovoltaic panel is directly connected to the hydrogen production power supply, and the hydrogen production power supply is directly connected to the electrolyzer at the rear stage. This type of solution will have the following problems:

[0004] 1. Load follows source: The energy supply of the hydrogen production electrolyzer is completely derived from the previous photovoltaic power generation system. Therefore, the working state of the hydrogen production electrolyzer is extremely dependent on the energy supply capacity of the previous photovoltaic power generation system. Once the energy supply is insufficient, the hydrogen production electrolyzer needs to be removed. Therefore, the electrolyzer needs to be frequently removed and put into operation during operation, resulting in frequent switching of the working conditions of the electrolyzer, affecting the stable operation and efficiency of hydrogen production.

[0005] 2. High control complexity: Since a single-stage hydrogen production power supply system is used, the hydrogen production power supply needs to realize the MPPT function of the photovoltaic panel on the one hand, and also needs to maintain the working voltage of the subsequent hydrogen production electrolyzer. However, it is difficult to simultaneously realize the MPPT control output of the photovoltaic panel and the output voltage stabilization control of the hydrogen production power supply by relying on the hydrogen production power supply, and it may even be impossible to achieve this. Not only is the control complexity high, but the control effect is also poor, and it is actually difficult to maintain a stable working voltage of the hydrogen production electrolyzer.

[0006] In summary, the traditional photovoltaic single-stage hydrogen production power supply has poor operating stability, needs to rely on the energy supply of the previous photovoltaic power generation system, and has high control complexity and poor control effect. If a large-capacity multi-new energy unit is connected in parallel to increase the energy supply of hydrogen production, since they all need to be connected through AC / DC or DC / DC converters, multi-stage energy conversion is required, which will lead to problems such as reduced efficiency. Summary of the invention

[0007] The technical problem to be solved by the present invention is: in response to the technical problems existing in the prior art, the present invention provides a photovoltaic-coupled hydrogen production power supply device with simple structure, low cost, high stability and efficiency, low control complexity and strong flexibility, and a system and a control method with simple implementation method, low control complexity, high control accuracy and efficiency.

[0008] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0009] A photovoltaic-coupled hydrogen production power supply device comprises: a first power supply module and a second power supply module, wherein the input end of the first power supply module is connected to the DC bus of a photovoltaic system, and the output end is connected to a hydrogen production electrolyzer, and the input end of the first power supply module is also connected to an energy storage system or a power generation system through the second power supply module, the first power supply module is used to access the DC power provided by the DC bus of the photovoltaic system for DC conversion to supply energy to the hydrogen production electrolyzer, and the second power supply module is used to access the electric energy of the energy storage system or the power generation system for conversion to provide supplementary electric energy to the hydrogen production electrolyzer through the first power supply module, or to access the excess electric energy output by the photovoltaic system to be sent back to the energy storage system or the power generation system.

[0010] Furthermore, the first power module includes a first DC conversion unit and a second DC conversion unit that are interconnected. The first DC conversion unit converts the DC voltage of the DC bus of the photovoltaic system or the DC voltage output by the second power module into a constant DC voltage, and outputs it to the second DC conversion unit. The second DC conversion unit steps up / down the received constant DC voltage to obtain the stepped-up / stepped DC power, which is provided to the hydrogen production electrolyzer.

[0011] Furthermore, the first DC conversion unit is a DC voltage stabilizing circuit with a buck-boost chopper structure.

[0012] Furthermore, the second DC conversion unit is an isolated conversion circuit of LLC type or DAB topology structure.

[0013] Furthermore, if the second power module is connected to the AC bus of the energy storage system or the power generation system, the second power module is an AC / DC bidirectional power supply; if the second power module is connected to the DC bus of the energy storage system or the power generation system, the second power module is a DC / DC bidirectional power supply.

[0014] Furthermore, it also includes a control module connected to the first power module and the second power module respectively, so as to preferentially control the first power module to access the DC power provided by the DC bus of the photovoltaic system for DC conversion to supply energy to the hydrogen-producing electrolyzer; when the energy provided by the photovoltaic system is insufficient, control the second power module to access the electric energy of the energy storage system or the power generation system for conversion to provide supplementary electric energy to the hydrogen-producing electrolyzer through the first power module; when the energy output by the photovoltaic system exceeds the energy demand of the hydrogen-producing electrolyzer, control the second power module to receive the excess electric energy output by the photovoltaic system and send it back to the energy storage system or the power generation system.

[0015] Furthermore, it also includes a pressure measuring module connected to the control module to monitor the change trend of the DC bus voltage and output it to the control module.

[0016] Furthermore, the control module is connected to the change trend of the DC bus voltage output by the pressure measuring module to control the output of the second power supply module to control the energy provided to reach a balance with the energy required by the hydrogen production electrolyzer, or to control the DC bus voltage to maintain the photovoltaic MPPT (Maximum power point track) working point voltage.

[0017] Furthermore, the pressure measuring module is a pressure measuring capacitor, and the pressure measuring capacitor is arranged at the output end of the second power supply module.

[0018] Furthermore, the first power module is provided with a plurality of output ports, and each of the output ports is respectively connected to the hydrogen production electrolyzer.

[0019] A photovoltaic coupled hydrogen production power system, comprising:

[0020] Photovoltaic systems;

[0021] Energy storage system or power generation system;

[0022] Electrolyzer for hydrogen production;

[0023] And as the above-mentioned hydrogen production power supply device, the input end of the hydrogen production power supply device is connected to the photovoltaic system and to the energy storage system or the power generation system, and the output end is connected to the hydrogen production electrolyzer;

[0024] A control method for the above hydrogen production power supply device, comprising the steps of:

[0025] Prioritizing the control of the first power module to access the direct current provided by the direct current bus of the photovoltaic system for direct current conversion to supply energy to the hydrogen production electrolyzer;

[0026] When the energy provided by the photovoltaic system is insufficient or in a dark environment, the second power module is controlled to access the electric energy of the energy storage system or the power generation system for conversion, so as to provide supplementary electric energy to the hydrogen production electrolyzer through the first power module;

[0027] When the energy output by the photovoltaic system exceeds the energy demand of the hydrogen production electrolyzer, the second power module is controlled to receive the excess electric energy output by the photovoltaic system and send it back to the energy storage system or the power generation system.

[0028] Furthermore, when controlling the second power supply module, the changing trend of the DC bus voltage is obtained, and the output of the second power supply module is controlled according to the changing trend of the DC bus voltage, so as to control the DC bus voltage to maintain the photovoltaic MPPT point operating voltage, and the photovoltaic MPPT point operating voltage is determined according to the light intensity in the environment.

[0029] Furthermore, if the total available power emitted by the photovoltaic system is less than the power required by the hydrogen production electrolyzer, it is determined that the energy provided by the photovoltaic system is insufficient, and the second power module is controlled to maintain the output MPPT working state voltage, and the output current of the second power module is controlled to raise the DC bus voltage so that the photovoltaic system remains in the MPPT state.

[0030] Furthermore, if the total available power generated by the photovoltaic system is greater than the power required by the hydrogen production electrolyzer, it is determined that the energy output by the photovoltaic system exceeds the energy demand of the hydrogen production electrolyzer, the first power module is kept operating at full load, and the second power module is controlled to absorb current and send energy back to the energy storage system or the power generation system to maintain the MPPT operating voltage state.

[0031] Furthermore, the first power module is connected to the hydrogen production electrolyzer through multiple output ports, and the control method also includes: if the total available power emitted by the photovoltaic system is greater than the power required by the hydrogen production electrolyzer, controlling the first power module to be fully put into operation; if the total available power emitted by the photovoltaic system is less than the power required by the hydrogen production electrolyzer and the shortage exceeds the power supply capacity of the second power module, controlling some of the output ports in the first power module to operate at full load, and the remaining one or more ports are in a non-full power working state.

[0032] Furthermore, it also includes controlling the second power module to increase or decrease the operating voltage of the DC bus to reduce the output power of the photovoltaic system if the total available power generated by the photovoltaic system is greater than the sum of the power required by the hydrogen production electrolyzer and the maximum acceptable power of the energy storage system or the power generation system.

[0033] An electronic device comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the computer program to perform the above method.

[0034] Compared with the prior art, the advantages of the present invention are:

[0035] 1. The present invention forms a two-stage photovoltaic-coupled hydrogen-production power supply device by two power modules. One power module is directly coupled to the photovoltaic system to form a photovoltaic direct-coupled hydrogen-production power supply as the main energy supply for hydrogen production. The other power module realizes a two-way energy flow between the energy storage system or the power generation system and the DC bus of the photovoltaic system. When the energy provided by the photovoltaic system is insufficient, the energy of the energy storage system or the power generation system is connected as a supplement. When there is a surplus of energy provided by the photovoltaic system, the surplus is returned, so that a balance can be achieved between the photovoltaic direct-coupled hydrogen-production power supply and the energy required for hydrogen production, effectively improving energy utilization. Based on the two-stage power supply structure, there is no need to require the photovoltaic direct-coupled hydrogen-production power supply to perform MPPT control and output voltage stabilization control of the hydrogen-production power supply at the same time, thereby greatly reducing the control complexity of the power supply and improving the control effect.

[0036] 2. The first power module of the present invention further adopts a two-stage DC conversion method, in which the first DC conversion unit realizes DC voltage stabilization, and the second DC conversion unit at the latter stage realizes voltage step-up / step-down and isolated output, which can improve the control effect and safety and reliability of the electrolyzer, and at the same time improve the power supply quality of the hydrogen production power supply to the electrolyzer.

[0037] 3. The present invention further realizes MPPT control of the direct-coupled photovoltaic system by adjusting the output of the second power module, which can decouple the MPPT control from the power demand of the electrolyzer, reduce the control complexity, and greatly improve the MPPT control tracking effect and the stable control effect of the output voltage of the hydrogen production power supply, thereby improving the utilization rate of photovoltaic power generation and the quality of electric energy provided to the hydrogen production electrolyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of the photovoltaic coupled hydrogen production power supply system of Example 1 of the present invention.

[0039] Figure 2 It is a structural schematic diagram of the photovoltaic coupled hydrogen production power supply system of Example 2 of the present invention.

[0040] Figure 3 It is a schematic diagram of the flow chart of controlling the photovoltaic coupled hydrogen production power supply device according to Embodiment 3 of the present invention.

[0041] Legend: 1. First power supply module; 101. First DC conversion unit; 102. Second DC conversion unit; 2. Second power supply module; 3. Pressure measurement module. DETAILED DESCRIPTION

[0042] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0043] As shown in the disclosure of the present invention, unless the context clearly indicates an exception, the words "one", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The words "first", "second" and similar words used in the disclosure of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0044] For a single-stage photovoltaic hydrogen production power source, since the energy supply of the hydrogen production electrolyzer is completely derived from the preceding photovoltaic power generation system, the working state of the hydrogen production electrolyzer will need to be extremely dependent on the energy supply capacity of the preceding photovoltaic power generation system, resulting in the electrolyzer's working conditions needing to be frequently switched, affecting the stable operation and efficiency of hydrogen production. At the same time, since the hydrogen production power source needs to realize the MPPT function of the photovoltaic panel on the one hand, and also needs to maintain the working voltage of the subsequent hydrogen production electrolyzer, not only is the control complexity high, but the control effect is also poor, and it is actually difficult to maintain a stable working voltage of the hydrogen production electrolyzer.

[0045] The present invention takes the above problems into consideration, and forms a two-stage photovoltaic coupled hydrogen production power supply device by two power modules, and forms a photovoltaic direct coupled hydrogen production power supply by directly coupling the photovoltaic system (the power module is directly connected to the photovoltaic system DC bus / busbar), realizing the energy coupling between photovoltaic power generation and hydrogen production power supply, and realizing the bidirectional energy flow between the energy storage system or the power generation system and the photovoltaic system DC bus by another power module, and connecting the energy of the energy storage system or the power generation system as a supplement when the energy provided by the photovoltaic system is insufficient, and returning the surplus energy provided by the photovoltaic system when there is surplus energy, so that the balance between the photovoltaic direct coupled hydrogen production power supply and the energy required for hydrogen production can be achieved, and the energy utilization rate can be effectively improved. Based on the two-stage power supply structure, there is no need to require the photovoltaic direct coupled hydrogen production power supply to simultaneously perform MPPT control and output voltage stabilization control of the hydrogen production power supply, so that the control complexity of the power supply can be greatly reduced and the control effect can be improved. In addition, based on the two-stage power supply structure, the directly coupled photovoltaic system does not need to increase the higher voltage, so only one level of conversion is needed to meet the power conversion requirements, and the energy conversion efficiency can be further ensured.

[0046] Embodiment 1:

[0047] like Figure 1 As shown, the photovoltaic coupled hydrogen production power supply device of this embodiment includes: a first power supply module 1 and a second power supply module 2, the input end of the first power supply module 1 is connected to the DC bus of the first photovoltaic system, and the output end is connected to the hydrogen production electrolyzer. The input end of the first power supply module 1 is also connected to the second photovoltaic system through the second power supply module 2. The first power supply module 1 is used to access the DC power provided by the DC bus of the photovoltaic system for DC conversion to supply energy to the hydrogen production electrolyzer, and the second power supply module 2 is used to access the electric energy of the second photovoltaic system for conversion to provide supplementary electric energy to the hydrogen production electrolyzer through the first power supply module 1, or to access the excess electric energy output by the first photovoltaic system and send it back to the second photovoltaic system, so as to realize the energy coupling of photovoltaic power generation and hydrogen production power supply. Since the hydrogen production power supply is directly coupled to the first photovoltaic system, the electric energy of the first photovoltaic system can be directly connected to the hydrogen production power supply, which can effectively reduce the number of energy conversion levels, avoid conversion losses, and improve conversion utilization. At the same time, the two-way flow of energy is realized through the second power module 2, and the second photovoltaic system provides the missing electric energy or sends back the excess energy, which can flexibly control the voltage output by the photovoltaic system, realize the coordinated control of the energy distribution of the first photovoltaic system and the second photovoltaic system, and balance the power generation of the directly coupled photovoltaic system and the energy demand of the hydrogen production power supply, thereby realizing a photovoltaic-coupled hydrogen production power supply with higher photovoltaic utilization, better electrolyzer voltage control effect and higher safety.

[0048] In this embodiment, the electric energy required for the hydrogen production power source all comes from the photovoltaic system (the first photovoltaic system and the second photovoltaic system), which can realize full photovoltaic power supply hydrogen production, effectively realize the local consumption of new energy, and improve the utilization rate of new energy. When realizing the coordinated control of energy distribution of the first photovoltaic system and the second photovoltaic system, the electric energy of the first photovoltaic system is used first, realizing full photovoltaic power generation and direct hydrogen production, and improving the local consumption capacity of renewable energy.

[0049] In a specific application embodiment, the first photovoltaic system can be specifically a small photovoltaic power station, that is, the photovoltaic power station has a small energy supply, and the photovoltaic power station is directly coupled with the hydrogen production power supply. The installed capacity of the directly coupled photovoltaic power station can be specifically configured to be similar to the hydrogen production power supply capacity; the second photovoltaic system is a large photovoltaic power station, that is, the photovoltaic power station has a large energy supply, and the photovoltaic output capacity of the second photovoltaic system is greater than that of the first photovoltaic system. The directly coupled photovoltaic power station (first photovoltaic system) is used as the main hydrogen production power supply system, and the photovoltaic power generation station (second photovoltaic system) is used as a secondary power supply / supplement system. It can be specifically configured to give priority to the use of small photovoltaic stations (first photovoltaic systems) to meet the power supply needs of hydrogen production, and the insufficient amount is compensated by the photovoltaic station (second photovoltaic system). The excess energy output by the small photovoltaic station (first photovoltaic system) is sent back to the photovoltaic station (second photovoltaic system) for recycling. It can be understood that the specific installed capacity of the first photovoltaic system and the second photovoltaic system can be configured according to actual needs. When the first power module 1 is connected to the second photovoltaic system through the second power module 2, it can be in parallel mode or in series mode.

[0050] In this embodiment, the first power module 1 includes a first DC conversion unit 111 and a second DC conversion unit 112 connected to each other. The first DC conversion unit 111 converts the DC voltage of the DC bus of the photovoltaic system or the DC voltage output by the second power module 2 into a constant DC voltage, and outputs it to the second DC conversion unit 112. The second DC conversion unit 112 steps up / down the received constant DC voltage to obtain the stepped-up / stepped DC power and provides it to the hydrogen production electrolyzer. The first power module 1 adopts the above-mentioned two-stage DC conversion method, in which the first DC conversion unit 111 realizes DC voltage stabilization, and the second DC conversion unit 112 at the latter stage realizes step-up / step-down and isolated output, which can improve the control effect and safety and reliability of the electrolyzer, and at the same time improve the power supply quality of the hydrogen production power supply to the electrolyzer.

[0051] In this embodiment, the first DC conversion unit 111 specifically adopts a DC voltage stabilizing circuit with a buck-boost chopper structure to convert the DC voltage of the DC bus of the photovoltaic system into a constant DC voltage. For example, a buck-boost chopper circuit composed of a Buck type, a Boost type, or other chopper circuits can be used. It is understandable that the first DC conversion unit 111 can also use other circuits that can achieve DC voltage conversion and voltage stabilization.

[0052] In this embodiment, the second DC conversion unit 112 specifically adopts an LLC (resonant) type isolation conversion circuit, that is, an LLC type DC / DC circuit, and uses a resonant circuit to achieve zero voltage switching (ZVS) and zero current switching (ZCS), thereby reducing switching losses and switching noise, and at the same time using soft switching technology to reduce the impact of instantaneous switching current and voltage, which can effectively improve the circuit safety and reliability, and realize the conversion of the DC voltage of the DC bus of the photovoltaic system into a constant DC voltage. It can be understood that the second DC conversion unit 112 can also use other types of isolation conversion circuits, such as a DC-DC conversion circuit with a DAB (dual active bridge) topology structure, etc., which can be specifically configured according to actual needs.

[0053] In this embodiment, the first power module 1 is specifically provided with a plurality of output ports, each of which is connected to the hydrogen production electrolyzer. Specifically, the second DC conversion unit 112 can adopt a converter with multi-port output, and the working state of the hydrogen production power electrolyzer can be regulated by controlling the input state of each output port. For example, when the energy is sufficient, all output ports can be selected to be input to meet the hydrogen production energy demand, and when the energy is insufficient, some ports can be disconnected to reduce the supply of hydrogen production energy.

[0054] In this embodiment, the second power module 2 is specifically a bidirectional current conversion power supply, which can realize the bidirectional flow of energy. If the second power module 2 is connected to the AC bus of the energy storage system or the power generation system, the second power module 2 can specifically adopt an AC / DC bidirectional current conversion power supply. If the second power module 2 is connected to the DC bus of the energy storage system or the power generation system, the second power module 2 can adopt a DC / DC bidirectional current conversion power supply.

[0055] In this embodiment, a control module connected to the first power module 1 and the second power module 2 is also included, which is used to preferentially control the first power module 1 to access the DC bus of the photovoltaic system to perform DC conversion to supply energy to the hydrogen production electrolyzer. When the energy provided by the first photovoltaic system is insufficient, the second power module 2 is controlled to access the energy storage system or the power generation system for conversion to provide supplementary electric energy to the hydrogen production electrolyzer through the first power module 1. When the energy output by the first photovoltaic system exceeds the energy demand of the hydrogen production electrolyzer, the second power module 2 is controlled to receive the excess electric energy output by the first photovoltaic system and send it back to the second photovoltaic system. The control module can meet the hydrogen production energy demand under different working conditions by controlling the energy flow between the first power module 1 and the second power module 2 and the photovoltaic system, so that the direct coupling photovoltaic system (the first photovoltaic system) and the hydrogen production energy demand can continuously reach a balanced state, effectively improving energy utilization and reliability.

[0056] It is understandable that the control module can be implemented by the internal control logic of each power module, or by an independently arranged control device, and the specific selection can be made according to actual needs.

[0057] In this embodiment, a pressure measuring module 3 connected to the control module is also included to monitor the changing trend of the DC bus voltage and output it to the control module. The control module is connected to the changing trend of the DC bus voltage output by the pressure measuring module 3, and controls the output of the second power module 2 according to the changing trend of the DC bus voltage, so as to control the energy provided and the energy required by the hydrogen production electrolyzer to reach a balanced state. For example, if the DC bus voltage drops to a certain threshold, the second power module 2 is controlled to output electric energy for supplementation. If the DC bus voltage rises to a certain threshold, the second power module 2 is controlled to return part of the electric energy to the second photovoltaic system. Since the DC bus voltage is indirectly controlled by controlling the output of the second power module 2, there is no need for the first power module 1 to simultaneously perform MPPT control and voltage stabilization control of the subsequent hydrogen production electrolyzer, thereby reducing the complexity of control and improving the control effect.

[0058] Furthermore, the control module can also control the DC bus voltage to maintain the photovoltaic MPPT working point voltage according to the changing trend of the DC bus voltage, so that the DC bus voltage is maintained at the photovoltaic MPPT working point voltage, thereby realizing MPPT control of the output voltage of the first photovoltaic system. The photovoltaic MPPT point working voltage can specifically be the working voltage of the DC bus / busbar, and the working voltage of the DC bus / busbar changes dynamically, and the specific value depends on the sunshine conditions, actual operating conditions, etc. Specifically, the photovoltaic MPPT point working voltage can be determined by detecting the working state of the photovoltaic panels of the first photovoltaic system, and the output of the second power supply module 2 can be controlled based on the changing trend of the DC bus voltage and the photovoltaic MPPT point working voltage, so as to indirectly control the working voltage output by the first photovoltaic system and maintain it in the MPPT working state. Since the first photovoltaic system is directly coupled to the hydrogen production power supply and MPPT control is achieved by controlling the output of the second power module 2, without the need for MPPT control at the front end of the hydrogen production power supply, the MPPT control can be decoupled from the power demand of the electrolyzer. The hydrogen production power supply can independently convert the changing input DC voltage into a constant DC output voltage, which can reduce the control complexity while greatly improving the MPPT control tracking effect and the stable control effect of the output voltage of the hydrogen production power supply, thereby improving the quality of the electric energy provided to the hydrogen production electrolyzer and the utilization rate of photovoltaic power generation.

[0059] In this embodiment, the pressure measuring module can specifically adopt a pressure measuring capacitor, and the pressure measuring capacitor is arranged at the output end of the second power module 2. By arranging the pressure measuring capacitor at the output side of the second power module 2, not only can the value and change trend of the bus voltage be reflected after the current injection and extraction of the second power module 2, so as to realize the measurement of the change trend of the DC bus voltage, but also the photovoltaic fluctuation energy can be smoothed. In this embodiment, the voltage at both ends of the pressure measuring capacitor is collected as the control input, and the output of the second power module 2 is adjusted according to the pressure measuring capacitor voltage and the photovoltaic MPPT point working voltage. The second power module 2 changes the voltage at both ends of the pressure measuring capacitor by absorbing or extracting current, and then maintains the DC bus / bus voltage at the photovoltaic MPPT working point voltage, so as to realize the maintenance of the photovoltaic MPPT working point voltage; after maintaining the DC bus / bus voltage, the first photovoltaic system can directly inject working current into the DC bus.

[0060] This embodiment further includes a photovoltaic coupled hydrogen production power system including:

[0061] Photovoltaic systems;

[0062] Energy storage system or power generation system;

[0063] Electrolyzer for hydrogen production;

[0064] And as the above-mentioned hydrogen production power supply device, the input end of the hydrogen production power supply device is connected to the photovoltaic system and the energy storage system or the power generation system, and the output end is connected to the hydrogen production electrolyzer.

[0065] Embodiment 2:

[0066] This embodiment is the same as the embodiment 1, except that the second photovoltaic system uses an energy storage system or other power generation system, such as a wind power generation system. Figure 2 As shown, the hydrogen production power supply function combining photovoltaic and energy storage systems can be realized, and the DC-coupled photovoltaic power station output is given priority. When the energy is insufficient, the electric energy provided by the energy storage system or other power generation system is used to supplement the energy. When there is a surplus of energy, the excess energy is returned to the energy storage system or other power generation system. If the second photovoltaic system adopts an energy storage system such as an energy storage power station, the reliability of hydrogen production power supply can be further improved. If the second photovoltaic system adopts a wind power generation device, the wind power generation energy can be further fully utilized. The energy storage system or other power generation system can also be further connected to the power grid to access energy from the power grid to supplement when the energy is insufficient, and when there is a surplus of energy, the excess energy is returned to the power grid.

[0067] Embodiment 3:

[0068] This embodiment is a control method for the photovoltaic coupled hydrogen production power supply device shown in Example 1. Figure 3 As shown, the steps of the control method include:

[0069] S01. Prioritize the control of the first power module 1 to access the DC bus of the first photovoltaic system to provide DC power conversion to supply energy to the hydrogen production electrolyzer;

[0070] S02. When the energy provided by the first photovoltaic system is insufficient or in a no-light environment, the second power module 2 is controlled to access the power of the second photovoltaic system for conversion to provide supplementary power to the hydrogen production electrolyzer through the first power module 1;

[0071] S03. When the energy output by the first photovoltaic system exceeds the energy demand of the hydrogen production electrolyzer, the second power module 2 is controlled to receive the excess electric energy output by the first photovoltaic system and send it back to the second photovoltaic system.

[0072] In this embodiment, when controlling the second power module 2, the change trend of the DC bus voltage is obtained, and the output of the second power module 2 is controlled according to the change trend of the DC bus voltage, so as to control the energy provided and the energy required by the hydrogen production electrolyzer to reach a balanced state, or control the DC bus voltage to maintain the photovoltaic MPPT point working voltage, and the photovoltaic MPPT point working voltage is obtained according to the working voltage of the DC bus. By controlling the DC bus voltage, the operating point of the photovoltaic panel in the direct-coupled photovoltaic system can be dynamically adjusted, that is, it can be far away from the MPPT point or close to the MPPT point, so that the MPPT converter does not need to operate at full power, and in most cases only needs to maintain the MPPT voltage.

[0073] In this embodiment, if the total available power emitted by the first photovoltaic system is less than the power required by the hydrogen production electrolyzer, it is determined that the energy provided by the first photovoltaic system is insufficient, and the second power module 2 is controlled to maintain the output MPPT working state voltage, and the second power module 2 is controlled to inject current into the pressure measuring module 3 to raise the DC bus voltage so that the photovoltaic system remains in the MPPT state.

[0074] In this embodiment, if the total available power emitted by the first photovoltaic system is greater than the power required by the hydrogen production electrolyzer, it is determined that the energy output by the first photovoltaic system exceeds the energy demand of the hydrogen production electrolyzer, the first power module 1 is kept working at full load, and the second power module 2 is controlled to absorb current from the pressure measuring module 3 and send the energy back to the energy storage system or the power generation system to maintain the MPPT working voltage state.

[0075] In this embodiment, the first power module 1 is connected to the hydrogen production electrolyzer through multiple output ports, and also includes: if the total available power emitted by the photovoltaic system is greater than the power required by the hydrogen production electrolyzer, the first power module 1 is controlled to be fully put into operation; if the total available power emitted by the first photovoltaic system is less than the power required by the hydrogen production electrolyzer and the shortage exceeds the power supply capacity of the second power module 2, some of the output ports in the first power module 1 are controlled to work at full load, and the remaining one or more ports are in a non-full power working state.

[0076] In this embodiment, if the total available power emitted by the first photovoltaic system is greater than the sum of the power required by the hydrogen production electrolyzer and the maximum power received by the second photovoltaic system, the second power supply module 2 is controlled to increase or decrease the operating voltage of the DC bus to reduce the output power of the first photovoltaic system.

[0077] Through the above control method, this embodiment can meet the control of the first photovoltaic system under different output power conditions, achieve the balance between the power required by the first photovoltaic system and the hydrogen production electrolyzer, and at the same time ensure that it works in the MPPT working state as much as possible to ensure energy utilization. It can be understood that the specific control method under each power condition can also be adjusted and optimized according to actual needs.

[0078] In a specific application embodiment, the detailed steps for implementing the control of the photovoltaic coupled hydrogen production power supply device are:

[0079] Step 1: Before the system is started, collect the information of the photovoltaic power station (the first photovoltaic system), evaluate the output power of the direct-coupled photovoltaic power station and the available margin of the photovoltaic large station (the second photovoltaic system), and determine the total photovoltaic available power;

[0080] Step 2: If the total photovoltaic available power is greater than the power required by the hydrogen production power supply, the output ends of the LLC isolated DC / DC circuit (the second DC conversion unit 102) in the hydrogen production power supply are controlled to be fully put into operation;

[0081] Step 3: If the power generated by the directly coupled photovoltaic power station is greater than the capacity of the hydrogen production power supply, the hydrogen production power supply is kept working at full load, and the second power supply returns part of the power to the photovoltaic power station while maintaining the MPPT working state voltage;

[0082] Step 4: In extreme cases, if the power generated by the direct-coupled photovoltaic power station is greater than the hydrogen production power capacity and the power capacity that the photovoltaic station can accept, the DC bus / busbar operating voltage is increased or decreased through the second power module 2, so that the photovoltaic panels in the direct-coupled photovoltaic power station operate at a non-MPPT operating point, thereby reducing the output power of the direct-coupled photovoltaic power station.

[0083] Maintain system energy balance;

[0084] Step 5: If the total photovoltaic available power is less than the power required by the hydrogen production power source, the second power module 2 absorbs power from the photovoltaic power station to the DC bus / busbar while maintaining the MPPT working state voltage;

[0085] Step 6: If the total photovoltaic available power is less than the power required by the hydrogen production power supply and exceeds the power supply capacity of the second power module 2, the number of output ports of the second DC conversion unit 102 in the hydrogen production power supply is calculated so that some ports work at full load and the remaining one or more ports are in a non-full power working state, thereby maintaining a power balance between the front-stage photovoltaic power generation power and the hydrogen production electrolyzer.

[0086] Step 7: If there is no sunlight, based on the conditions of the photovoltaic station, use the photovoltaic station equipment to absorb a certain amount of electricity from the grid to meet the power demand of the hydrogen production power supply.

[0087] This embodiment also provides an electronic device, including a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the computer program to perform the above method.

[0088] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A photovoltaic coupled hydrogen production power supply device, characterized in that: include: A first power module (1) and a second power module (2), wherein the input end of the first power module (1) is connected to the DC bus of the photovoltaic system, and the output end is connected to the hydrogen production electrolyzer. The input end of the first power module (1) is also connected to the energy storage system or the power generation system through the second power module (2). The first power module (1) is used to access the DC power provided by the DC bus of the photovoltaic system for DC conversion to supply energy to the hydrogen production electrolyzer. The second power module (2) is used to access the electric energy of the energy storage system or the power generation system for conversion to provide supplementary electric energy to the hydrogen production electrolyzer through the first power module (1), or to access the excess electric energy output by the photovoltaic system to be sent back to the energy storage system or the power generation system.

2. The photovoltaic coupled hydrogen production power supply device according to claim 1, characterized in that: The first power module (1) comprises a first DC conversion unit (101) and a second DC conversion unit (102) which are connected to each other. The first DC conversion unit (101) converts the DC voltage of the DC bus of the photovoltaic system or the DC voltage output by the second power module (2) into a constant DC voltage, and outputs it to the second DC conversion unit (102). The second DC conversion unit (102) steps up / down the received constant DC voltage to obtain the stepped-up / stepped DC power, which is then supplied to the hydrogen production electrolyzer.

3. The photovoltaic coupled hydrogen production power supply device according to claim 2, characterized in that: The first DC conversion unit (101) is a DC voltage stabilizing circuit with a buck-boost chopper structure.

4. The photovoltaic coupled hydrogen production power supply device according to claim 2, characterized in that: The second DC conversion unit (102) is an isolated conversion circuit of LLC type or DAB topology structure.

5. The photovoltaic coupled hydrogen production power supply device according to claim 1, characterized in that: If the second power module (2) is connected to the AC bus of the energy storage system or the power generation system, the second power module (2) is an AC / DC type bidirectional current conversion power supply; if the second power module (2) is connected to the DC bus of the energy storage system or the power generation system, the second power module (2) is a DC / DC type bidirectional current conversion power supply.

6. The photovoltaic coupled hydrogen production power supply device according to any one of claims 1 to 5, characterized in that: The invention also includes a control module connected to the first power module (1) and the second power module (2) respectively, so as to preferentially control the first power module (1) to access the direct current provided by the direct current bus of the photovoltaic system for direct current conversion so as to supply energy to the hydrogen production electrolyzer; when the energy provided by the photovoltaic system is insufficient, the second power module (2) is controlled to access the electric energy of the energy storage system or the power generation system for conversion so as to provide supplementary electric energy to the hydrogen production electrolyzer through the first power module (1); when the energy output by the photovoltaic system exceeds the energy demand of the hydrogen production electrolyzer, the second power module (2) is controlled to receive the excess electric energy output by the photovoltaic system and send it back to the energy storage system or the power generation system.

7. The photovoltaic coupled hydrogen production power supply device according to any one of claims 1 to 5, characterized in that: It also includes a pressure measuring module (3) connected to the control module, which is used to monitor the change trend of the DC bus voltage and output it to the control module.

8. The photovoltaic coupled hydrogen production power supply device according to claim 7, characterized in that: The control module is connected to the change trend of the DC bus voltage output by the pressure measuring module (3), and controls the output of the second power module (2) to control the energy provided and the energy required by the hydrogen production electrolyzer to reach a balanced state, or controls the DC bus voltage to maintain the photovoltaic MPPT working point voltage.

9. The photovoltaic coupled hydrogen production power supply device according to claim 7, characterized in that: The pressure measuring module (3) is a pressure measuring capacitor, and the pressure measuring capacitor is arranged at the output end of the second power supply module (2).

10. The photovoltaic coupled hydrogen production power supply device according to any one of claims 1 to 5, characterized in that: The first power module (1) is provided with a plurality of output ports, and each of the output ports is respectively connected to the hydrogen production electrolyzer.

11. A photovoltaic coupled hydrogen production power system, characterized in that: include: Photovoltaic systems; Energy storage system or power generation system; Electrolyzer for hydrogen production; And the photovoltaic-coupled hydrogen production power supply device as described in claims 1 to 10, the input end of the hydrogen production power supply device is connected to the photovoltaic system and to the energy storage system or the power generation system, and the output end is connected to the hydrogen production electrolyzer.

12. A control method for the photovoltaic coupled hydrogen production power supply device according to any one of claims 1 to 10, characterized in that the steps include: Prioritizing the control of the first power module (1) to access the direct current provided by the direct current bus of the photovoltaic system for direct current conversion, so as to supply energy to the hydrogen production electrolyzer; When the energy provided by the photovoltaic system is insufficient or in a dark environment, the second power module (2) is controlled to access the electric energy of the energy storage system or the power generation system for conversion, so as to provide supplementary electric energy to the hydrogen production electrolyzer through the first power module (1); When the energy output by the photovoltaic system exceeds the energy demand of the hydrogen production electrolyzer, the second power module (2) is controlled to receive the excess electric energy output by the photovoltaic system and send it back to the energy storage system or the power generation system.

13. The control method according to claim 12, characterized in that: When controlling the second power module (2), the variation trend of the DC bus voltage is obtained, and the output of the second power module (2) is controlled according to the variation trend of the DC bus voltage, so as to control the DC bus voltage to maintain the photovoltaic MPPT point operating voltage, wherein the photovoltaic MPPT point operating voltage is determined according to the light intensity in the environment.

14. The control method according to claim 12, characterized in that: If the total available power generated by the photovoltaic system is less than the power required by the hydrogen production electrolyzer, it is determined that the energy provided by the photovoltaic system is insufficient, and the second power module (2) is controlled to maintain the output MPPT working state voltage, and the second power module (2) is controlled to output current to raise the DC bus voltage so that the photovoltaic system is maintained in the MPPT state.

15. The control method according to claim 12, characterized in that: If the total available power generated by the photovoltaic system is greater than the power required by the hydrogen production electrolyzer, it is determined that the energy output by the photovoltaic system exceeds the energy demand of the hydrogen production electrolyzer, the first power module (1) is kept working at full load, and the second power module (2) is controlled to absorb current and send energy back to the energy storage system or the power generation system to maintain the MPPT working voltage state.

16. The control method according to any one of claims 12 to 15, characterized in that: The first power module (1) is connected to the hydrogen production electrolyzer via a plurality of output ports, and the control method further comprises: if the total available power emitted by the photovoltaic system is greater than the power required by the hydrogen production electrolyzer, controlling the first power module (1) to be fully operational; if the total available power emitted by the photovoltaic system is less than the power required by the hydrogen production electrolyzer and the shortfall exceeds the power supply capacity of the second power module (2), controlling some of the output ports in the first power module (1) to operate at full load, and the remaining one or more ports to be in a non-full power operating state.

17. The control method according to any one of claims 12 to 15, characterized in that: It also includes controlling the second power module (2) to increase or decrease the operating voltage of the DC bus to reduce the output power of the photovoltaic system if the total available power generated by the photovoltaic system is greater than the sum of the power required by the hydrogen production electrolyzer and the maximum acceptable power of the energy storage system or the power generation system.

18. An electronic device comprising a processor and a memory, wherein the memory is used to store a computer program, wherein: The processor is configured to execute the computer program to perform the method according to any one of claims 12 to 17.

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