A hybrid electrolytic hydrogen production system and an energy management method based on its dynamic characteristics

Abstract

The present invention belongs to the technical field of hydrogen production, and particularly relates to a hybrid electrolytic hydrogen production system and an energy management method based on its dynamic characteristics, which utilize the complementary characteristics between high-cost and high-performance electrolyzers and low-cost and low-performance electrolyzers to jointly produce hydrogen under the background of renewable energy. Therefore, the energy management method of the present invention can determine the electric power that the energy buffer module can output or the electric power that needs to be input according to all available power output by renewable energy, as well as the input power allocated to the hydrogen production module, and consider the dynamic response characteristics of different electrolyzers, so as to transform the dynamic response characteristics of the electrolyzers into an affine function of renewable energy fluctuations, and be able to allocate the high-frequency components to high-performance electrolyzers and the low-frequency components to ordinary electrolyzers, thereby fully utilizing renewable energy to produce hydrogen, maximizing the hydrogen production of the hybrid electrolytic hydrogen production system, and avoiding the influence of renewable energy fluctuations on hydrogen production.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production, and particularly relates to a hybrid electrolytic hydrogen production system and an energy management method based on its dynamic characteristics. Background Art

[0002] With the continuous improvement of the popularity of Renewable Energy Sources (RESs), the conversion problem between electric energy and hydrogen energy needs to be studied urgently. On the one hand, hydrogen can be used as a long-term energy storage technology to store the energy generated by renewable energy and can be converted into electric energy later; on the other hand, hydrogen can be used as a raw material for producing other chemical products such as ammonia.

[0003] In order to produce hydrogen using renewable energy, various technologies are being developed. Among them, the Alkaline Electrolyzer (AEL) and the Proton Exchange Membrane Electrolyzer (PEMEL) are relatively popular hydrogen production technologies. Although the alkaline electrolyzer technology is relatively mature and the cost is relatively low, its working power range is relatively narrow and its dynamic response characteristics are relatively poor. The proton exchange membrane electrolyzer technology is better in terms of working power range and dynamic response characteristics, but its technology maturity is relatively low and the cost is relatively high.

[0004] Currently, most hydrogen production systems only adopt one electrolyzer technology and do not utilize the complementary characteristics between the alkaline electrolyzer and the proton exchange membrane electrolyzer, which in turn affects the hydrogen production and the economic benefits of hydrogen production.

[0005] In addition, in order to make full use of the dynamic response characteristics of the proton exchange membrane electrolyzer to fully adapt to the fluctuations of renewable energy, it is necessary to design a reasonable energy management strategy to make the hydrogen production system work efficiently. Summary of the Invention

[0006] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to propose a hybrid electrolytic hydrogen production system, which uses renewable energy as the energy source of the system, and utilizes the complementary characteristics of high-cost and high-performance electrolyzers and low-cost and low-performance electrolyzers, such as alkaline electrolyzers and proton exchange membrane electrolyzers, and utilizes the dynamic response characteristics of the proton exchange membrane electrolyzer to adapt to the high-frequency components generated by the fluctuations of renewable energy, so as to maximize the hydrogen production and ensure the efficient operation of the hybrid electrolytic hydrogen production system.

[0007] To achieve the above and other related objectives, the present invention provides a hybrid electrolytic hydrogen production system, including: a hydrogen production module, including two or more electrolyzers, and at least one of them is a high-performance electrolyzer with high dynamic response and wide power operation range, which is used to complement the relatively lower-performance ordinary electrolyzers to produce hydrogen; a power supply module, used to convert renewable energy into electrical energy for output; an energy buffer module, used for charging energy storage and discharging energy supply; a control module, used to control the energy buffer module to discharge when the electrical energy output of the power supply module is insufficient, so as to maintain the minimum operating power of the hydrogen production module; and used to control the energy buffer module to charge or discharge when the electrical energy output of the power supply module fluctuates, so as to balance the electrical energy output of the power supply module, and control the hydrogen production module to work to produce hydrogen according to the dynamic response characteristics of the electrolyzer; wherein, the energy buffer module includes one or more of supercapacitors and batteries, and the supercapacitor includes a lithium-ion capacitor, and the battery includes a lithium-ion battery, a sodium-ion battery, and a solid-state battery.

[0008] An energy management method based on the dynamic characteristics of a hybrid electrolytic hydrogen production system, applied to the above-mentioned hybrid electrolytic hydrogen production system, includes: obtaining the electrical energy output by the power supply module; determining the electrical power that the energy buffer module can output or the electrical power that needs to be input according to the total available power of the electrical energy, and the input power allocated to the hydrogen production module; allocating the high-frequency component in the input power of the hydrogen production module to the high-performance electrolyzer in the hydrogen production module to produce hydrogen according to the dynamic response characteristics of the electrolyzer, and allocating the low-frequency component in the input power of the hydrogen production module to the ordinary electrolyzer in the hydrogen production module to produce hydrogen.

[0009] According to a specific embodiment of the present invention, the steps of determining the electrical power that the energy buffer module can output or the electrical power that needs to be input according to the total available power of the electrical energy, and the input power allocated to the hydrogen production module include: constructing a first objective function based on the state of charge of the energy buffer module; constructing a first affine function according to the dynamic response ability of the energy buffer module to constrain the first objective function; minimizing the first objective function to maximize the input power of the hydrogen production module and minimize the fluctuation of the state of charge of the energy buffer module, and calculating the input power of the hydrogen production module and the electrical power that the energy buffer module can output or the electrical power that needs to be input.

[0010] According to a specific embodiment of the present invention, the steps of determining the electrical power that the energy buffer module can output or the electrical power that needs to be input according to the total available power of the electrical energy, and the input power allocated to the hydrogen production module further include: constraining the first objective function according to the power balance of the hybrid electrolytic hydrogen production system, the ramp rate of the hydrogen production module, and the power operation range of the hydrogen production module.

[0011] According to a specific embodiment of the present invention, the formula of the first objective function J 1 , the power balance of the hybrid electrolytic hydrogen production system, the ramp rate of the hydrogen production module, and the constraints of the power operation range of the hydrogen production module are as follows:

[0012]

[0013] Constraint on the power balance of the hybrid electrolytic hydrogen production system: P res (t) + P sc (t) = P hes (t),

[0014] Constraint on the ramp rate of the hydrogen production module:

[0015] Constraint on the power operation range of the hydrogen production module: P hesmin ≤ P hes (t) ≤ P hesmax ,

[0016] where 0 - t f represents the time period during which the hydrogen production module operates, P hes (t) represents the input power of the hydrogen production module, SOC init represents the initial state of charge of the energy buffer module, SOC end represents the final state of charge of the energy buffer module, ω represents the weight of the state of charge conversion energy, P res (t) represents the total available power of the electric energy, P sc (t) represents the input / output power of the energy buffer module, P hes (t) represents the input power of the hydrogen production module, P hesmin represents the lower limit of the operating power of the hydrogen production module, P hesmax represents the upper limit of the operating power of the hydrogen production module, represents the fluctuation change of the input power of the hydrogen production module within the sampling time T s , that is, the ramp rate.

[0017] According to a specific embodiment of the present invention, the formula of the first affine function constructed based on the dynamic response ability of the energy buffer module is as follows:

[0018] P sc (t) = A 1 (t)P res (t) - A 2 (t)avg(P res (t)),

[0019] where A 1(t) represents the first gain coefficient, and A 1 (t) ∈ [0.6, 1], A 2 (t) represents the first base coefficient, avg(P res (t)) represents the average value of all available power of the electric energy, P sc (t) represents the input / output power of the energy buffer module.

[0020] According to a specific embodiment of the present invention, the steps of distributing the high-frequency component in the input power of the hydrogen production module to the high-performance electrolytic cell in the hydrogen production module to produce hydrogen, and distributing the low-frequency component in the input power of the hydrogen production module to the ordinary electrolytic cell in the hydrogen production module to produce hydrogen according to the dynamic response characteristics of the electrolytic cell include: establishing a second objective function based on the hydrogen production of the high-performance electrolytic cell and the ordinary electrolytic cell; constructing a second affine function according to the dynamic response ability of the high-performance electrolytic cell to constrain the second objective function; minimizing the second objective function to maximize the total hydrogen production of the hydrogen production module, and calculating the hydrogen production per unit of the high-performance electrolytic cell and the ordinary electrolytic cell; according to the hydrogen production per unit of the high-performance electrolytic cell and the ordinary electrolytic cell, and based on the number of units configured for the high-performance electrolytic cell and the ordinary electrolytic cell, calculating the power distribution of the high-performance electrolytic cell and the ordinary electrolytic cell in the hydrogen production module.

[0021] According to a specific embodiment of the present invention, the steps of calculating the power distribution of the high-performance electrolytic cell and the ordinary electrolytic cell in the hydrogen production module according to the hydrogen production per unit of the high-performance electrolytic cell and the ordinary electrolytic cell, and based on the number of units configured for the high-performance electrolytic cell and the ordinary electrolytic cell include: calculating the hydrogen production of the high-performance electrolytic cell according to the number of units and the hydrogen production per unit of the high-performance electrolytic cell, and calculating the hydrogen production of the ordinary electrolytic cell according to the number of units and the hydrogen production per unit of the ordinary electrolytic cell; obtaining the input power of the high-performance electrolytic cell and the ordinary electrolytic cell based on the hydrogen production of the high-performance electrolytic cell and the ordinary electrolytic cell; wherein, the hydrogen production of the high-performance electrolytic cell and the ordinary electrolytic cell is linearly related to their corresponding input power, and the input power of the high-performance electrolytic cell is the high-frequency component in the input power of the hydrogen production module, and the input power of the ordinary electrolytic cell is the low-frequency component in the input power of the hydrogen production module.

[0022] According to a specific embodiment of the present invention, the formula of the second objective function J 2 and its related constraints are as follows:

[0023]

[0024] The constraint of the power operation range of the ordinary electrolytic cell: Paemin ≤P ae (t)≤P aemax ,

[0025] Constraints on the power operation range of the high-performance electrolyzer: 0 ≤ P pe (t) ≤ P pemax ,

[0026] Constraints on the power balance of the hydrogen production module: P hes (t) = P ae (t) + P pe (t),

[0027] and P ae (t) = x ae P aeb (t), P pe (t) = x pe P peb (t),

[0028] Constraints on the ramp rate of the ordinary electrolyzer:

[0029] Constraints on the ramp rate of the high-performance electrolyzer:

[0030] where β H represents the unit price of the sold hydrogen, 0 - t f is the time period during which the hydrogen production module operates, x ae represents the number of monomers configured in the ordinary electrolyzer, x pe represents the number of monomers configured in the high-performance electrolyzer, n aeb (t) represents the hydrogen production per monomer of the ordinary electrolyzer, n peb (t) represents the hydrogen production per monomer of the high-performance electrolyzer, P aemin represents the lower limit of the operating power of the ordinary electrolyzer, P aemax represents the upper limit of the operating power of the ordinary electrolyzer, P pemax represents the upper limit of the operating power of the high-performance electrolyzer, P hes (t) represents the input power of the hydrogen production module, P ae (t) represents the input power of the ordinary electrolyzer, P pe (t) represents the input power of the high-performance electrolyzer, P aeb (t) represents the input power per monomer of the ordinary electrolyzer, P peb (t) represents the input power per monomer of the high-performance electrolyzer, represents the fluctuation change of the input power of the ordinary electrolyzer monomer within the sampling time T s i.e., the ramp rate, Indicates the fluctuation of the input power of the high-performance electrolyzer cell within the sampling time T, i.e., the ramp rate. s That is, the ramp rate.

[0031] According to a specific embodiment of the present invention, the formula of the second affine function constructed based on the dynamic response ability of the high-performance electrolyzer is as follows:

[0032] P pe (t) = B 1 (t)P hes (t) - B 2 (t)min(P hes (t)),

[0033] where B 1 (t) ∈ [0.6, 1], B 2 (t) represents the second base coefficient, min(P hes (t)) represents the minimum value of the input power of the hydrogen production module, and P pe (t) represents the input power of the high-performance electrolyzer.

[0034] The present invention provides a hybrid electrolytic hydrogen production system, which can make full use of renewable energy to produce hydrogen by utilizing the complementary characteristics of high-cost high-performance electrolyzers and low-cost low-performance electrolyzers, and can improve the hydrogen production compared with a single electrolyzer.

[0035] At the same time, the present invention also provides an energy management method for the hybrid electrolytic hydrogen production system, which can not only keep the state of charge of the energy buffer device in the system stable, thereby maintaining the stable operation of the system, but also utilize the dynamic response characteristics of the electrolyzer to allocate power to the hybrid electrolyzer, and can effectively allocate the high-frequency component of the power in the renewable energy to the electrolyzer with better dynamic response characteristics, and allocate the low-frequency component of the power to the electrolyzer with poor dynamic response characteristics, so as to maximize the hydrogen production of the system and greatly improve the economic benefits brought by hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 FIG. is a schematic structural diagram of a specific embodiment of a hybrid electrolytic hydrogen production system provided by the present invention;

[0037] Figure 2 FIG. is a schematic structural diagram of another specific embodiment of a hybrid electrolytic hydrogen production system provided by the present invention;

[0038] Figure 3 FIG. is a schematic structural diagram of still another specific embodiment of a hybrid electrolytic hydrogen production system provided by the present invention;

[0039] Figure 4 FIG. is a schematic flow chart of a specific embodiment of an energy management and capacity configuration method provided by the present invention;

[0040] Figure 5 Schematic flow chart of a specific embodiment of an energy management method based on the static characteristics of a hybrid electrolytic hydrogen production system provided by the present invention;

[0041] Figure 6 Schematic flow chart of a specific embodiment of an energy management method based on the dynamic characteristics of a hybrid electrolytic hydrogen production system provided by the present invention;

[0042] Figure 7 Schematic flow chart of a specific embodiment of an energy management and capacity configuration method based on the static and dynamic characteristics of a hybrid electrolytic hydrogen production system provided by the present invention. Detailed implementation mode

[0043] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the protection scope of the present invention.

[0044] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0045] In the following description, a large number of details are explored to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0046] Please refer to Figure 1As shown, a hybrid electrolytic hydrogen production system includes a hydrogen production module 10, a power supply module 20, and a control module 30. Among them, the power supply module 20 can convert renewable energy into electrical energy for output, such as photovoltaic power generation, wind power generation, hydroelectric power generation, etc., to meet the power demand of the system. There are no excessive restrictions on renewable energy, and the power generation devices corresponding to renewable energy can be configured according to the environmental factors of the hydrogen production site. The hydrogen production module 10 can be composed of a mixture of two or more electrolyzers to produce hydrogen using the electrical energy output by the power supply module 20. It can be understood that in this embodiment, the hydrogen production system is constructed by utilizing the complementary characteristics between different electrolyzers. For example, the alkaline electrolyzer has poor dynamic response but low cost, and the proton exchange membrane electrolyzer has good dynamic response but high cost, so they can be mixed and complementary. Therefore, the hydrogen production module 10 mentioned in this embodiment is composed of a mixture of two electrolyzers with different characteristics or more than two electrolyzers with different characteristics, rather than a mixture of electrolyzers with the same characteristics, as that would not produce any beneficial effects.

[0047] Specifically, the hydrogen production module 10 at least includes one high-performance electrolyzer with high dynamic response and wide power operation range to address the problems of unstable and fluctuating renewable energy. It should be noted here that the hybrid electrolytic hydrogen production system constructed in this embodiment uses renewable energy as the energy source to produce hydrogen, so that the renewable energy can be converted into another form of energy for storage, or economic benefits can be created using renewable energy. However, at the same time, the instability of renewable energy often affects hydrogen production. For example, photovoltaic power generation cannot produce enough electrical energy for hydrogen production during rainy weather, wind power generation cannot do so during windless weather, and hydroelectric power generation cannot do so when the water level remains unchanged.

[0048] Therefore, as Figure 2 shown, the hybrid electrolytic hydrogen production system can also be equipped with an energy buffer module 40, which can discharge and supply energy when the power supply module 20 cannot output sufficient electrical energy to maintain the basic operation of the hydrogen production module 10 and even the hybrid electrolytic hydrogen production system, that is, the hydrogen production module 10 and the hybrid electrolytic hydrogen production system operate at the minimum power.

[0049] Furthermore, when a sudden strong wind blows, causing wind power generation to greatly increase its electrical energy output in a short period of time, or a heavy rainstorm causes the water level to suddenly rise, resulting in a great increase in hydroelectric power generation's electrical energy output in a short period of time, if the response speed of the electrolyzer is poor, it cannot adapt to the instantaneously increased electrical energy to produce hydrogen using it, thus correspondingly reducing the hydrogen production.

[0050] For example, originally, wind power generation or hydropower generation could output relatively stable electrical energy of 150 kW. However, due to weather factors, the electrical energy output increased to 200 kW, that is, the output increased by 50 kW in a short period of time. If the response speed of the electrolyzer is poor, such as that of an alkaline electrolyzer, it cannot utilize the extra 50 kW to produce hydrogen, which may result in a waste of 50 kW of electrical energy. Therefore, in this embodiment, the hydrogen production module 10 quickly responds to the 50 kW electrical energy fluctuation change through a high-performance electrolyzer and uses it to continue producing hydrogen, thereby increasing the hydrogen production and adapting to the fluctuation change of renewable energy.

[0051] It can be understood that high-performance electrolyzers usually have a high cost. If only high-performance electrolyzers are used to produce hydrogen to address the instability and large fluctuations of renewable energy, it will greatly increase the investment cost and correspondingly reduce the economic benefits of hydrogen production. Therefore, by mixing electrolyzers with lower costs, that is, ordinary electrolyzers, not only can the investment cost be reduced, but also the fluctuation change of renewable energy can be adapted, effectively increasing the hydrogen production and its economic benefits.

[0052] In addition, the energy buffer module 40 can not only discharge energy to maintain the hydrogen production module 10 operating at the minimum power when the power output of the power supply module 20 is insufficient, but also charge / discharge correspondingly when the power output of the power supply module 20 fluctuates. For example, it can charge and store energy when the power supply module 20 outputs a positive fluctuation to balance the increased electrical energy part, or discharge energy to supply power when the power supply module 20 outputs a negative fluctuation to compensate for the missing electrical energy part, thereby maintaining the stable operation of the hydrogen production module 10.

[0053] In this regard, the energy buffer module 40 in this embodiment can adopt one or more of a supercapacitor (SC) and a battery. The supercapacitor includes a lithium-ion capacitor, and the battery includes a lithium-ion battery, a sodium-ion battery, and a solid-state battery. There are no specific restrictions. Those skilled in the art, without departing from the spirit of the present invention, the modifications and refinements made to the embodiments of the present invention still fall within the scope of the invention application patent of the present invention.

[0054] Based on the above, the control module 30 correspondingly controls the operation of the hydrogen production module 10 and / or the energy buffer module 40 according to the power output of the power supply module 20. For example, when the energy buffer module 40 is configured in the system, it can control the energy buffer module 40 to discharge when the power output of the power supply module 20 is insufficient to maintain the hydrogen production module operating at the minimum power, and control the energy buffer module 40 to charge or discharge when the power output of the power supply module 20 fluctuates, so as to control the hydrogen production module 10 to produce hydrogen after balancing or compensating the power output of the power supply module 20.

[0055] In practical applications, preferably, such as Figure 3As shown, the hybrid electrolytic hydrogen production system is not limited to the above hydrogen production module 10, power supply module 20, control module 30, and energy buffer module 40. It also needs to be configured with corresponding DC / DC (direct current / direct current) converters and AC / DC (alternating current / direct current) converters for power conversion. For example, if the power generated by wind power is alternating current, an AC / DC converter is required to convert the alternating current into direct current and deliver it to the DC bus so that the hydrogen production module 10 can use it. At the same time, usually the voltage on the DC bus is relatively large, far exceeding the operating voltage of the electrolyzer, and a DC / DC converter is needed to regulate the DC voltage. Similarly, photovoltaic power generation also needs to be boosted by a DC / DC converter and then delivered to the DC bus. The supercapacitor can boost and discharge or step down and charge through a DC / DC converter, which are all well-known technical means to those skilled in the art and will not be described in detail here.

[0056] Therefore, the control module 30 also needs to control the operation of the DC / DC converter and AC / DC converter in the system to meet the working requirements of different functional module units.

[0057] It should be noted that the above Figure 3 is only a preferred embodiment in practical applications, but does not limit the protection scope of this application. For example, renewable energy is not limited to wind power generation and photovoltaic power generation, the energy buffer module is not limited to supercapacitors, and high-performance electrolyzers are not limited to proton exchange membrane electrolyzers, etc. Without departing from the spirit of the present invention, the modifications and refinements made by those skilled in the art to the embodiments of the present invention still fall within the scope of the invention patent application of the present invention.

[0058] Furthermore, since the above system adapts to the fluctuations of renewable energy through a hybrid electrolyzer, thereby increasing the hydrogen production and maximizing the net hydrogen production income. In this regard, this embodiment also provides a corresponding energy management method, which reasonably plans the power distribution of high-performance electrolyzers and ordinary electrolyzers based on the electrical energy of renewable energy. For specific details, please refer to the following different embodiments:

[0059] Embodiment 1

[0060] Please refer to Figure 4 the energy management and capacity configuration method of a hybrid electrolytic hydrogen production system shown. First of all, it should be noted that in order to better elaborate the energy management method of this application, in this embodiment, the high-performance electrolyzer in the hydrogen production module is taken as an example of a proton exchange membrane electrolyzer, the ordinary electrolyzer is taken as an example of an alkaline electrolyzer, and the energy buffer module is not considered for the time being. Only Figure 1How the shown hybrid electrolytic hydrogen production system conducts energy management. Secondly, the energy management method of this embodiment can not only achieve power distribution between the alkaline electrolyzer and the proton exchange membrane electrolyzer, but also complete the capacity configuration of the alkaline electrolyzer and the proton exchange membrane electrolyzer in the hybrid electrolytic hydrogen production system, that is, considering the economic benefits of hydrogen production, how many alkaline electrolyzers and how many proton exchange membrane electrolyzers should be configured, and their corresponding total capacity sizes, so as to implement the energy management method of this application in practical applications. Specifically as follows:

[0061] Step S110, establish an objective function based on the investment costs, capacity sizes, and hydrogen production of the high-performance electrolyzer and the ordinary electrolyzer in the hydrogen production module.

[0062] It should be noted here that due to the poor stability of renewable energy, its output power fluctuates greatly, and the response speed of the alkaline electrolyzer cannot adapt to the fluctuating changes of renewable energy, so the suddenly increased power of renewable energy cannot be reasonably utilized to produce hydrogen.

[0063] Therefore, by adding a proton exchange membrane electrolyzer to quickly respond to the fluctuating changes of renewable energy and complement the alkaline electrolyzer to produce hydrogen. And considering the economic benefits of hydrogen production, it is necessary to reasonably configure the capacities of the alkaline electrolyzer and the proton exchange membrane electrolyzer, that is, the corresponding number of monomers. It can be understood here that usually, the proportion of the part of the power that renewable energy can stably output is relatively large, and the alkaline electrolyzer can fully utilize this part of the power to produce hydrogen, while the part of the power with fluctuating changes is relatively small, and the alkaline electrolyzer cannot achieve a quick response. Correspondingly, the proton exchange membrane electrolyzer is used to utilize this part of the power to produce hydrogen, so as to increase the hydrogen production of the hybrid electrolytic hydrogen production system. At the same time, on the premise that the hybrid electrolytic hydrogen production system can fully utilize renewable energy to produce hydrogen, as few proton exchange membrane electrolyzers as possible can be configured to reduce the investment cost of the hybrid electrolytic hydrogen production system, correspondingly increase the net income brought by hydrogen production, and avoid waste of resources caused by redundancy of proton exchange membrane electrolyzers.

[0064] Specifically, the objective function J can be referred to as follows:

[0065]

[0066]

[0067] Among them, C ae represents the investment cost of the alkaline electrolyzer, x ae represents the number of monomers of the alkaline electrolyzer, P aebmax represents the upper limit of the monomer operating power of the alkaline electrolyzer, C pe represents the investment cost of the proton exchange membrane electrolyzer, x peIndicates the number of single cells of the proton exchange membrane electrolyzer, P pebmax Indicates the upper limit of the operating power of a single cell of the proton exchange membrane electrolyzer, β H Indicates the unit price of the sold hydrogen, 0 - t f The time period during which the hydrogen production module operates, n aeb (t) represents the hydrogen production amount per single cell of the alkaline electrolyzer, n peb (t) represents the hydrogen production amount per single cell of the proton exchange membrane electrolyzer, C aepc Indicates the unit price of the alkaline electrolyzer, y ae Indicates the service life of the alkaline electrolyzer, C pepc Indicates the unit price of the proton exchange membrane electrolyzer, y pe Indicates the service life of the proton exchange membrane electrolyzer, r represents the annual interest rate, T test Indicates the number of test days in a year.

[0068] At the same time, in order to ensure reasonable power distribution and capacity configuration, the following constraint conditions are added:

[0069] Constraint on the power balance of the hydrogen production module: P hes (t) = P ae (t) + P pe (t),

[0070] And P ae (t) = x ae P aeb (t), P pe (t) = x pe P peb (t),

[0071] Constraint on the capacity balance of the hydrogen production module: P hesmax (t) = x ae P aebmax (t) + x pe P pebmax (t),

[0072] Constraint on the ramp rate of the alkaline electrolyzer:

[0073] Constraint on the ramp rate of the proton exchange membrane electrolyzer:

[0074] Constraint on the power operation range of the alkaline electrolyzer: P aemin ≤P ae (t) ≤ P aemax , that is, x ae P aebmin ≤P ae (t) ≤ x ae P aebmax ,

[0075] Power operation range constraint of proton exchange membrane electrolyzer: 0 ≤ P pe (t) ≤ P pemax , that is, 0 ≤ P pe (t) ≤ x pe P pebmax ,

[0076] Among them, P hes (t) represents the input power of the hydrogen production module, P ae (t) represents the input power of the alkaline electrolyzer, P pe (t) represents the input power of the proton exchange membrane electrolyzer, P aeb (t) represents the single-cell input power of the alkaline electrolyzer, P peb (t) represents the single-cell input power of the proton exchange membrane electrolyzer, P hesmax (t) represents the upper limit of the operating power of the hydrogen production module, that is, the capacity of the hydrogen production module, P aemin represents the lower limit of the operating power of the alkaline electrolyzer, P aemax represents the upper limit of the operating power of the said alkaline electrolyzer, that is, the capacity of the alkaline electrolyzer, P pemax represents the upper limit of the operating power of the proton exchange membrane electrolyzer, that is, the capacity of the proton exchange membrane electrolyzer, represents the fluctuation change of the input power of the alkaline electrolyzer single cell within the sampling time T s , that is, the ramp rate, represents the fluctuation change of the input power of the proton exchange membrane electrolyzer single cell within the sampling time T s , that is, the ramp rate, P aebmax (t) represents the upper limit of the single-cell operating power of the alkaline electrolyzer, that is, the single-cell capacity of the alkaline electrolyzer, P pebmax (t) represents the upper limit of the single-cell operating power of the proton exchange membrane electrolyzer, that is, the single-cell capacity of the proton exchange membrane electrolyzer.

[0077] Step S120, according to the input power of the hydrogen production module, use the target function to configure the capacity and allocate the power of the high-performance electrolyzer and the ordinary electrolyzer in the hydrogen production module to maximize the economic benefits of hydrogen production.

[0078] Based on the above target function J and its related constraint conditions, it can be understood that the purpose of the target function J is to control the total investment cost of the alkaline electrolyzer and the proton exchange membrane electrolyzer, and to control the total hydrogen production of the alkaline electrolyzer and the proton exchange membrane electrolyzer. Since the investment cost of the proton exchange membrane electrolyzer is relatively high, while the investment cost of the alkaline electrolyzer is relatively low, in order to increase the net income of hydrogen production, the number of proton exchange membrane electrolyzers should be as small as possible to reduce the investment cost of the hydrogen production module.

[0079] Therefore, minimizing the objective function J can minimize the total investment cost of the hydrogen production module and maximize the total hydrogen production of the hydrogen production module. Moreover, the number of single units of the alkaline electrolyzer and the proton exchange membrane electrolyzer to be configured can be calculated accordingly, as well as the hydrogen production per single unit of the alkaline electrolyzer and the proton exchange membrane electrolyzer.

[0080] Furthermore, given the single unit capacity of the alkaline electrolyzer and the proton exchange membrane electrolyzer, the capacity configuration of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be calculated accordingly based on the number of single units to be configured. Secondly, the hydrogen production of the alkaline electrolyzer and the proton exchange membrane electrolyzer can also be calculated based on the number of single units and the corresponding hydrogen production per single unit of the alkaline electrolyzer and the proton exchange membrane electrolyzer. It can be understood here that the hydrogen production of the electrolyzer reflects the amount of its input power. The more the input power, the more the corresponding hydrogen production; the less the input power, the less the corresponding hydrogen production, fully reflecting that the hydrogen production of the electrolyzer is linearly related to its input power. Therefore, based on the hydrogen production calculated for the alkaline electrolyzer and the proton exchange membrane electrolyzer, the power distribution of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be achieved.

[0081] Thus, by utilizing the complementary characteristics of the alkaline electrolyzer and the proton exchange membrane electrolyzer and achieving the capacity configuration and power distribution of the hybrid electrolyzer based on the above objective function J, the electric power converted from renewable energy can be fully utilized to produce hydrogen, so as to improve the economic benefits brought by hydrogen production.

[0082] It should be noted that the step division of the above various methods is only for clear description. When implemented, they can be combined into one step or some steps can be split into multiple steps. As long as the same logical relationship is included, they are all within the protection scope of this patent; adding insignificant modifications to the algorithm or process or introducing insignificant designs, but not changing the core design of its algorithm and process are all within the protection scope of this patent.

[0083] Embodiment 2

[0084] Please refer to Figure 5An energy management method based on the static characteristics of a hybrid electrolytic hydrogen production system is shown. First of all, it should be noted that in order to better elaborate the energy management method of this application, in this embodiment, the high-performance electrolyzer in the hydrogen production module takes the proton exchange membrane electrolyzer as an example, the ordinary electrolyzer takes the alkaline electrolyzer as an example, and the energy buffer module takes the supercapacitor as an example to fully elaborate the energy management method of this embodiment. Secondly, based on the above-mentioned Embodiment 1, the same method can be used to realize the capacity configuration and energy management of the hybrid electrolyzer in this embodiment. However, since Embodiment 1 has fully explained how to perform the capacity configuration, therefore, this will not be elaborated in this embodiment, nor is it used to limit the combination of the technical means of Embodiment 1 and this embodiment, and there is no excessive limitation on this. The energy management method is as follows:

[0085] Step S210, obtain the electric energy output by the power supply module.

[0086] Step S220, determine the electric power that the energy buffer module can output or the electric power that needs to be input according to all available powers of the electric energy, and the input power allocated to the hydrogen production module.

[0087] Here, it can be understood that due to the instability of renewable energy, the supercapacitor needs to discharge and supply energy when the power supply module cannot output electric energy or cannot output sufficient electric energy to maintain the basic operation of the hydrogen production module and even the system; for example, at least keep the electrolyzer in the on state so that hydrogen production can start quickly when renewable energy provides sufficient electric energy. Or discharge and supply energy when there is a reverse fluctuation in renewable energy to maintain the stable operation of the hydrogen production module; for example, if the electric energy output by wind power generation at the next moment is less than that at the previous moment, it can be compensated by the discharge of the supercapacitor, thereby maintaining the hydrogen production amount of the hydrogen production module.

[0088] However, at the same time, considering that it is necessary to keep the state of charge (SOC) of the supercapacitor stable in order to maintain the subsequent steady-state operation of the system, therefore, renewable energy can also be used to charge the supercapacitor to keep its SOC within a preset range to avoid its SOC being too low. It can be imagined that once the supply of renewable energy is interrupted while the SOC of the supercapacitor is too low, it will lead to an energy crisis in the system, and the steady-state operation environment will be correspondingly damaged, causing immeasurable losses. In addition, keeping the SOC of the supercapacitor within a reasonable range can also prevent its SOC from being in a low or high state for a long time, preventing overcharging or over-discharging.

[0089] Based on the above, it is first necessary to determine the preliminary power distribution according to all available power in the electric energy output by the power supply module, that is, to determine the input power allocated to the hydrogen production module and the electric power that the supercapacitor can output or needs to input. For example, when the available power output by renewable energy fluctuates positively, all its available power can be respectively allocated to the hydrogen production module for hydrogen production and the supercapacitor for charging; when the available power output by renewable energy fluctuates negatively, the supercapacitor can output electric power to supply energy to the hydrogen production module together with the available power output by renewable energy.

[0090] Therefore, first construct the first objective function J based on the SOC of the supercapacitor 1 , as follows:

[0091]

[0092] Among them, 0 - t f represents the operation time period of the hydrogen production module, P hes (t) represents the input power of the hydrogen production module, SOC init represents the initial SOC of the supercapacitor, SOC end represents the final SOC of the supercapacitor, and ω represents the weight of the charge state conversion energy.

[0093] At the same time, in order to ensure reasonable power distribution, the following constraint conditions are added:

[0094] Constraint on the power balance of the hybrid electrolytic hydrogen production system: P res (t) + P sc (t) = P hes (t),

[0095] Constraint on the ramp rate of the hydrogen production module:

[0096] Constraint on the power operation range of the hydrogen production module: P hesmin ≤P hes (t) ≤ P hesmax ,

[0097] Among them, P res (t) represents all available power output by the power supply module, P sc (t) represents the input / output power of the supercapacitor, P hesmin represents the lower limit of the operating power of the hydrogen production module, P hesmax represents the upper limit of the operating power of the hydrogen production module, represents the fluctuation change of the input power of the hydrogen production module within the sampling time T s , that is, the ramp rate.

[0098] Based on the above first objective function J1 , and its related constraints, it can be understood that the first objective function J 1 aims to allocate as much power as possible to the hydrogen production module to increase the hydrogen production amount and to maintain the SOC of the supercapacitor as stable as possible.

[0099] Therefore, minimizing the first objective function J 1 can maximize the input power of the hydrogen production module and minimize the fluctuation of the SOC of the supercapacitor. And the change value of the SOC of the supercapacitor can be calculated accordingly.

[0100] Here it can be understood that the SOC of the supercapacitor is positively correlated with its input / output power, that is, when the SOC decreases, it corresponds to the supercapacitor discharging and outputting power externally, and when the SOC increases, it corresponds to the supercapacitor charging and receiving external input power. Thus, the electric power that the supercapacitor can output or the electric power that needs to be input can be obtained. When the power input / output by the supercapacitor is determined, the input power of the hydrogen production module can be determined accordingly, thereby completing the preliminary power distribution.

[0101] Step S230, allocate the input power of the hydrogen production module to the high-performance electrolyzer and the ordinary electrolyzer in the hydrogen production module respectively according to the static characteristics of the electrolyzer to produce hydrogen.

[0102] Based on the above, after completing the preliminary power distribution, the input power of the hydrogen production module can be determined accordingly, that is, the input power of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be further allocated to produce hydrogen.

[0103] Here it can be understood that on the premise that the capacity configuration of the hybrid electrolyzer has been completed, a second objective function J can be directly constructed with the purpose of hydrogen production amount, 2 specifically as follows:

[0104]

[0105] where x ae represents the number of monomers of the alkaline electrolyzer, x pe represents the number of monomers of the proton exchange membrane electrolyzer, β H represents the unit price of the sold hydrogen, 0 - t f is the time period during which the hydrogen production module operates, n aeb (t) represents the hydrogen production amount per monomer of the alkaline electrolyzer, n peb (t) represents the hydrogen production amount per monomer of the proton exchange membrane electrolyzer.

[0106] Similarly, as described in Embodiment 1 above, the following constraints are also added:

[0107] Constraint on the power balance of the hydrogen production module: P hes (t) = Pae (t) + P pe (t),

[0108] and P ae (t) = x ae P aeb (t), P pe (t) = x pe P peb (t),

[0109] Ramp rate constraint of the alkaline electrolyzer:

[0110] Ramp rate constraint of the proton exchange membrane electrolyzer:

[0111] where P hes (t) represents the input power of the hydrogen production module, P ae (t) represents the input power of the alkaline electrolyzer, P pe (t) represents the input power of the proton exchange membrane electrolyzer, P aeb (t) represents the input power per cell of the alkaline electrolyzer, P peb (t) represents the input power per cell of the proton exchange membrane electrolyzer, represents the fluctuation of the input power per cell of the alkaline electrolyzer within the sampling time T s i.e., the ramp rate, represents the fluctuation of the input power per cell of the proton exchange membrane electrolyzer within the sampling time T s i.e., the ramp rate, P aebmax (t) represents the upper limit of the operating power per cell of the alkaline electrolyzer, P pebmax (t) represents the upper limit of the operating power per cell of the proton exchange membrane electrolyzer.

[0112] It can be understood here that since the capacities of the alkaline electrolyzer and the proton exchange membrane electrolyzer have been configured, there is no longer a need for capacity balancing to constrain the second objective function J 2 .

[0113] Furthermore, considering the static characteristics of the electrolyzer, namely the hydrogen-in-oxygen capacity and overload capacity, to ensure the reliable and stable operation of the hybrid electrolysis hydrogen production system and its effective working. Therefore, the operating power range of the electrolyzer can be determined according to its hydrogen-in-oxygen capacity and overload capacity. Specifically, the lower limit of the single-cell operating power of the electrolyzer can be obtained based on the maximum threshold of its corresponding hydrogen-to-oxygen (HTO). For example, when the HTO of the alkaline electrolyzer reaches 2%, the alkaline electrolyzer needs to stop working to avoid explosion. At the same time, for the alkaline electrolyzer, the HTO decreases with the increase of the current. Therefore, to ensure that the HTO is lower than a certain value, the input current of the alkaline electrolyzer needs to be higher than a certain specific value, which means that the input power needs to be higher than a certain specific value, and thus the lower limit of the single-cell operating power of the alkaline electrolyzer can be obtained. The upper limit of the working power of the alkaline electrolyzer is related to its overload capacity. Under normal circumstances, the working power of the alkaline electrolyzer can reach 110% of its rated power. However, frequent overload may accelerate the degradation of the alkaline electrolyzer. Therefore, the upper limit of the single-cell operating power of the alkaline electrolyzer can be determined according to the actual situation.

[0114] For the proton exchange membrane electrolyzer, since its power range is relatively wide and its corresponding input current can be greater than or equal to 0, therefore, the lower limit of its single-cell operating power can be 0. It can be understood that the high-performance electrolyzer in this embodiment takes the proton exchange membrane electrolyzer as an example, so its lower limit of operating power is specifically 0, but when the high-performance electrolyzer uses other electrolyzers, the corresponding lower limit of operating power needs to be recalculated based on its hydrogen-in-oxygen capacity. In addition, the proton exchange membrane electrolyzer can operate at a power up to 160% of its rated power, and there are not many restrictions on the lower limit of the power. Therefore, the upper limit of the single-cell operating power of the proton exchange membrane electrolyzer can be determined according to the actual situation.

[0115] Based on the above, the second objective function J can be constrained according to the hydrogen-in-oxygen capacity and overload capacity of the alkaline electrolyzer and the proton exchange membrane electrolyzer 2 That is, the corresponding power operating range is obtained through the hydrogen-in-oxygen capacity and overload capacity of the electrolyzer, and the second objective function J 2 is constrained, specifically as follows:

[0116] Power operating range constraint of the alkaline electrolyzer: P aemin ≤P ae (t)≤P aemax , that is, x ae P aebmin ≤P ae (t)≤x ae P aebmax ,

[0117] Power operating range constraint of the proton exchange membrane electrolyzer: 0≤P pe (t)≤Ppemax , that is, 0 ≤ P pe (t) ≤ x pe P pebmax ,

[0118] Among them, P aemin represents the lower limit of the operating power of the alkaline electrolyzer, and P aemax represents the upper limit of the operating power of the alkaline electrolyzer, and P pemax represents the upper limit of the operating power of the proton exchange membrane electrolyzer, and P aebmax (t) represents the upper limit of the monomer operating power of the alkaline electrolyzer, and P pebmax (t) represents the upper limit of the monomer operating power of the proton exchange membrane electrolyzer.

[0119] Based on the above objective function J 2 and its related constraint conditions, it can be understood that the purpose of the objective function J 2 is to control the total hydrogen production of the alkaline electrolyzer and the proton exchange membrane electrolyzer.

[0120] Therefore, minimizing the objective function J 2 can maximize the total hydrogen production of the hydrogen production module. And the hydrogen production of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be calculated accordingly.

[0121] Similarly, as described in the above Embodiment 1, based on the hydrogen production of the alkaline electrolyzer and the proton exchange membrane electrolyzer, and the number of monomers of the alkaline electrolyzer and the proton exchange membrane electrolyzer, the hydrogen production of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be calculated, and then the power distribution of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be realized. Here, it can be understood that since the capacity configuration of the alkaline electrolyzer and the proton exchange membrane electrolyzer has been completed, the number of monomers thereof can be directly used as a known quantity for calculation, and the hydrogen production of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be obtained accordingly.

[0122] It can be seen that by utilizing the complementary characteristics of the alkaline electrolyzer and the proton exchange membrane electrolyzer, and based on the above second objective function J 2 , at the same time, fully considering the static characteristics of the electrolyzer, and then realizing the power distribution of the hybrid electrolyzer, it is possible to fully utilize the electric power converted from renewable energy to produce hydrogen, so as to improve the economic benefits brought by hydrogen production, and also improve the reliability of the hybrid electrolysis hydrogen production system, ensuring its stable and efficient operation.

[0123] It should be noted that the step division of the above various methods is only for clear description. When implemented, they can be combined into one step or some steps can be split into multiple steps. As long as the same logical relationship is included, they are all within the protection scope of this patent; adding insignificant modifications to the algorithm or process or introducing insignificant designs, but not changing the core design of its algorithm and process, are all within the protection scope of this patent.

[0124] Embodiment 3

[0125] Please refer to Figure 6 An energy management method based on the dynamic characteristics of a hybrid electrolytic hydrogen production system as shown. First of all, it should be noted that in order to better elaborate the energy management method of this application, similar to Embodiment 2, the high-performance electrolytic cell in the hydrogen production module takes the proton exchange membrane electrolytic cell as an example, the ordinary electrolytic cell takes the alkaline electrolytic cell as an example, and the energy buffer module takes the supercapacitor as an example to fully elaborate the energy management method of this embodiment. Secondly, the capacity configuration of the hybrid electrolytic cell is not elaborated in detail again. Only how to realize the energy management of the hybrid electrolytic hydrogen production system is specifically elaborated. Of course, it is not used to limit Embodiment 1 either. Combining the technical means of Embodiment 1, Embodiment 2 and this embodiment, there is no excessive limitation on this. The energy management method is as follows:

[0126] Step S310, obtain the electric energy output by the power supply module.

[0127] Step S320, determine the electric power that the energy buffer module can output or needs to input, and the input power allocated to the hydrogen production module according to all available power of the electric energy.

[0128] Similarly, considering that it is necessary to keep the SOC of the supercapacitor stable, first, it is necessary to determine the preliminary power distribution according to all available power in the electric energy output by the power supply module, that is, to determine the input power allocated to the hydrogen production module, and the electric power that the supercapacitor can output or needs to input.

[0129] Furthermore, based on the SOC of the supercapacitor, construct the first objective function J 1 , and its related constraint conditions are as follows:

[0130]

[0131] Constraint of power balance of the hybrid electrolytic hydrogen production system: P res (t)+P sc (t)=P hes (t),

[0132] Constraint of the ramp rate of the hydrogen production module:

[0133] Constraints on the power operation range of the hydrogen production module: P hesmin ≤P hes (t)≤P hesmax ,

[0134] where 0 - t f represents the time period during which the hydrogen production module operates, P hes (t) represents the input power of the hydrogen production module, SOC init represents the initial SOC of the supercapacitor, SOC end represents the final SOC of the supercapacitor, ω represents the weight of the charge state conversion energy, P res (t) represents all the available power output by the power supply module, P sc (t) represents the input / output power of the supercapacitor, P hesmin represents the lower limit of the operating power of the hydrogen production module, P hesmax represents the upper limit of the operating power of the hydrogen production module, represents the fluctuation change of the input power of the hydrogen production module within the sampling time T s , that is, the ramp rate.

[0135] Secondly, since the dynamic response speeds of the hydrogen production module and the supercapacitor are different, in order to utilize the corresponding dynamic response capabilities to better achieve the preliminary power distribution, affine control is used to convert the dynamic response parameters of the supercapacitor into an affine function of the renewable energy fluctuation, and the first affine function P sc (t) of the supercapacitor is constructed accordingly to constrain the first objective function J 1 . Specifically, it can be referred to as follows:

[0136] P sc (t) = A 1 (t)P res (t) - A 2 (t)avg(P res (t)),

[0137] where A 1 (t) represents the first gain coefficient, and A 1 (t) ∈ [0.6, 1], A 2 (t) represents the first base coefficient, which can be set according to the actual situation, and avg(P res (t)) represents the mean value of all the available power of the electric energy.

[0138] Similarly, as described in the above Embodiment 2, based on the above first objective function J 1 , and its related constraint conditions, the SOC change value of the supercapacitor can be calculated accordingly, that is, the electric power that the supercapacitor can output or the electric power that needs to be input, as well as the input power of the hydrogen production module, so as to complete the preliminary power distribution.

[0139] Step S330: According to the dynamic response characteristics of the electrolyzer, allocate the high-frequency component in the input power of the hydrogen production module to the high-performance electrolyzers in the hydrogen production module to produce hydrogen, and allocate the low-frequency component in the input power of the hydrogen production module to the ordinary electrolyzers in the hydrogen production module to produce hydrogen.

[0140] Similarly, based on the above, after the preliminary power distribution is completed, the input power of the hydrogen production module can be correspondingly determined, that is, the input power of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be further allocated to produce hydrogen. And, on the premise that the capacity configuration of the hybrid electrolyzer has been completed, the second objective function J can be directly constructed with the hydrogen production as the goal 2 , and its related constraint conditions are as follows:

[0141]

[0142] Constraint on the power balance of the hydrogen production module: P hes (t) = P ae (t) + P pe (t),

[0143] And P ae (t) = x ae P aeb (t), P pe (t) = x pe P peb (t),

[0144] Constraint on the ramp rate of the alkaline electrolyzer:

[0145] Constraint on the ramp rate of the proton exchange membrane electrolyzer:

[0146] Constraint on the power operation range of the alkaline electrolyzer: P aemin ≤ P ae (t) ≤ P aemax , that is, x ae P aebmin ≤ P ae (t) ≤ x ae P aebmax ,

[0147] Constraint on the power operation range of the proton exchange membrane electrolyzer: 0 ≤ P pe (t) ≤ P pemax , that is, 0 ≤ P pe (t) ≤ x pe P pebmax ,

[0148] Among them, x ae represents the number of single cells of the alkaline electrolyzer, xpe Denotes the number of single units of a proton exchange membrane electrolyzer, β H Denotes the unit price of the hydrogen sold, 0 - t f The time period during which the hydrogen production module operates, n aeb η(t) denotes the hydrogen production per single unit of the alkaline electrolyzer, n peb η(t) denotes the hydrogen production per single unit of the proton exchange membrane electrolyzer, P hes P(t) denotes the input power of the hydrogen production module, P ae P(t) denotes the input power of the alkaline electrolyzer, P pe P(t) denotes the input power of the proton exchange membrane electrolyzer, P aeb P(t) denotes the input power per single unit of the alkaline electrolyzer, P peb P(t) denotes the input power per single unit of the proton exchange membrane electrolyzer, Denotes the fluctuation of the input power of a single unit of the alkaline electrolyzer within the sampling time T s That is, the ramp rate, Denotes the fluctuation of the input power of a single unit of the proton exchange membrane electrolyzer within the sampling time T s That is, the ramp rate, P aebmax P(t) denotes the upper limit of the operating power per single unit of the alkaline electrolyzer, P pebmax P(t) denotes the upper limit of the operating power per single unit of the proton exchange membrane electrolyzer, P aemin Denotes the lower limit of the operating power of the alkaline electrolyzer, P aemax Denotes the upper limit of the operating power of the said alkaline electrolyzer, P pemax Denotes the upper limit of the operating power of the proton exchange membrane electrolyzer, P aebmax P(t) denotes the upper limit of the operating power per single unit of the alkaline electrolyzer, P pebmax P(t) denotes the upper limit of the operating power per single unit of the proton exchange membrane electrolyzer.

[0149] It should be noted here that although the power distribution of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be achieved according to the above, in order to make full use of renewable energy to produce hydrogen and further maximize the hydrogen production. In this embodiment, considering the dynamic response characteristics of the electrolyzer, the input power of the hydrogen production module is divided into a high-frequency component and a low-frequency component, and they are respectively allocated to the alkaline electrolyzer and the proton exchange membrane electrolyzer, so as to give full play to the high dynamic response and wide power operation range capabilities of the proton exchange membrane electrolyzer. It can be understood that the high-frequency component is the part of the power that fluctuates, and the low-frequency component is the part of the power with stable output. For example, the output power of renewable energy fluctuates in the range of 200 - 250 kW, and 100 kW is allocated to the supercapacitor for charging. The output power that can be allocated to the alkaline electrolyzer and the proton exchange membrane electrolyzer fluctuates in the range of 100 - 150 kW. Here, the fluctuating output power in 100 - 150 kW is only 50 kW, and at least 100 kW of the output power value is stable at the current stage. Therefore, the low-frequency component, that is, 100 kW, can be allocated to the alkaline electrolyzer, and the remaining high-frequency component, that is, 50 kW, can be allocated to the proton exchange membrane electrolyzer.

[0150] It can be seen that by dividing the input power of the hydrogen production module into high-frequency and low-frequency components for distribution, the advantages of the hybrid electrolyzer can be maximally utilized, enabling the hybrid electrolytic hydrogen production system to maintain an efficient working state, maximizing hydrogen production, and thus improving economic benefits.

[0151] In this regard, in order to better utilize the dynamic response characteristics of the proton exchange membrane electrolyzer, affine control is used to convert the dynamic response parameters of the proton exchange membrane electrolyzer into an affine function of the input power of the hydrogen production module, and a second affine function P pe (t) of the proton exchange membrane electrolyzer is constructed accordingly to constrain the second objective function J 2 . Specifically, it can be referred to as follows:

[0152] P pe (t) = B 1 (t)P hes (t) - B 2 (t)min(P hes (t)),

[0153] where B 1 (t) represents the second gain coefficient, and B 1 (t) ∈ [0.6, 1], B 2 (t) represents the second base coefficient, which can be set according to the actual situation, and min(P hes (t)) represents the minimum value of the input power of the hydrogen production module.

[0154] Similarly, as described in the above Embodiment 2, based on the above first objective function J 1 , and its related constraint conditions, the hydrogen production per unit of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be calculated, and based on the number of units of the alkaline electrolyzer and the proton exchange membrane electrolyzer, the hydrogen production of the alkaline electrolyzer and the proton exchange membrane electrolyzer can be calculated, thereby realizing the power distribution between the alkaline electrolyzer and the proton exchange membrane electrolyzer. And it can be understood that the input power of the proton exchange membrane electrolyzer is the high-frequency component in the input power of the hydrogen production module, and the input power of the alkaline electrolyzer is the low-frequency component in the input power of the hydrogen production module.

[0155] Thus, by utilizing the complementary characteristics of the alkaline electrolyzer and the proton exchange membrane electrolyzer, and based on the above second objective function J 2 , at the same time, fully considering the dynamic response characteristics of the proton exchange membrane electrolyzer, the alkaline electrolyzer and the proton exchange membrane electrolyzer can make full use of the electric power converted from renewable energy, maximize the hydrogen production of the hybrid electrolytic hydrogen production system, ensure the efficient operation of the hybrid electrolytic hydrogen production system, and bring huge economic benefits.

[0156] It should be noted that the step division of the above various methods is only for clear description. When implemented, they can be combined into one step or some steps can be split into multiple steps. As long as they contain the same logical relationship, they are all within the protection scope of this patent; adding insignificant modifications to the algorithm or process or introducing insignificant designs, but not changing the core design of its algorithm and process are all within the protection scope of this patent.

[0157] In summary, the above three embodiments respectively elaborate on the energy management method of the hybrid electrolytic hydrogen production system and adopt different technical means to maintain the reliable, stable and efficient operation of the hybrid electrolytic hydrogen production system, and then make full use of the complementary characteristics of the alkaline electrolyzer and the proton exchange membrane electrolyzer to produce hydrogen, so as to improve the economic benefits of hydrogen production. However, at the same time, it can be understood that the energy management method of the hybrid electrolytic hydrogen production system can be obtained by combining the technical features of any two or three of Embodiment 1, Embodiment 2, and Embodiment 3. For example, as shown in Figure 7 , by combining Embodiment 1, Embodiment 2, and Embodiment 3, using the static characteristics (hydrogen in oxygen ability and overload ability) and dynamic response characteristics of the electrolyzer to realize the energy management and capacity configuration method of the hybrid electrolytic hydrogen production system. Those skilled in the art, without departing from the spirit of the present invention, the modifications and refinements made to the embodiments of the present invention still fall within the scope of the patent application of the present invention.

[0158] The present invention provides a hybrid electrolytic hydrogen production system, which can make full use of renewable energy to produce hydrogen by leveraging the complementary characteristics of high-cost and high-performance electrolyzers and low-cost and low-performance electrolyzers, and can increase the hydrogen production compared with a single electrolyzer.

[0159] Meanwhile, the present invention also provides an energy management method for the hybrid electrolytic hydrogen production system, which can keep the SOC of the energy buffer device in the system stable, thereby maintaining the stable operation of the system. For the purpose of maximizing the net hydrogen production income, the static characteristics (hydrogen-in-oxygen capacity and overload capacity) and dynamic response characteristics of the electrolyzer are used to achieve the capacity configuration and power distribution of the electrolyzer, so as to maximize the hydrogen production and greatly improve the economic benefits brought by hydrogen production.

[0160] The above embodiments only exemplarily illustrate the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A hybrid electrolysis hydrogen production system, characterized in that: include: A hydrogen production module, comprising two or more electrolyzers, wherein at least one of the electrolyzers has a high-performance electrolyzer with a high dynamic response and a wide power operation range, and is used to complement the other common electrolyzers with relatively low performance in preparing hydrogen; A power supply module for converting renewable energy into electrical output; An energy buffer module, used for charging energy storage and discharging energy supply, and the energy buffer module includes one or more of a supercapacitor and a battery, and the supercapacitor includes a lithium-ion capacitor, and the battery includes a lithium-ion battery, a sodium-ion battery, and a solid-state battery; A control module, used for controlling the energy buffer module to discharge when the power output of the power supply module is insufficient, so as to maintain the minimum operating power of the hydrogen production module; and used to control the charging or discharging of the energy buffer module when the power output of the power supply module fluctuates, so as to balance the power output of the power supply module, and control the hydrogen production module to produce hydrogen according to the dynamic response characteristics of the electrolyzer; A first objective function is constructed based on the state of charge of the energy buffer module, and a first affine function is constructed according to the dynamic response capability of the energy buffer module to constrain the first objective function; and the first objective function is constrained according to the power balance of the hybrid electrolysis hydrogen production system, the ramp rate of the hydrogen production module, and the power operation range of the hydrogen production module; The control module maximizes the input power of the hydrogen production module and minimizes the fluctuation of the charge state of the energy buffer module by minimizing the first objective function, and calculates the input power of the hydrogen production module and the electric power that the energy buffer module can output or needs to input.

2. An energy management method based on the dynamic characteristics of a hybrid electrolysis hydrogen production system, characterized in that: The hybrid electrolysis hydrogen production system as claimed in claim 1 comprises: Obtain the electric energy output by the power supply module; Determine the electric power that can be output by the energy buffer module or the electric power that needs to be input, and the input power allocated to the hydrogen production module based on the total available power of the electric energy, and the steps include: constructing a first objective function based on the state of charge of the energy buffer module; constructing a first affine function based on the dynamic response capability of the energy buffer module to constrain the first objective function; minimizing the first objective function to maximize the input power of the hydrogen production module and minimize the fluctuation of the state of charge of the energy buffer module, and calculate the input power of the hydrogen production module and the electric power that can be output by the energy buffer module or the electric power that needs to be input; wherein, the first objective function is constrained based on the power balance of the hybrid electrolysis hydrogen production system, the ramp rate of the hydrogen production module, and the power operation range of the hydrogen production module; According to the dynamic response characteristics of the electrolyzer, the high-frequency component of the input power of the hydrogen production module is allocated to the high-performance electrolyzer in the hydrogen production module to prepare hydrogen, and the low-frequency component of the input power of the hydrogen production module is allocated to the ordinary electrolyzer in the hydrogen production module to prepare hydrogen.

3. The energy management method based on the dynamic characteristics of the hybrid electrolysis hydrogen production system according to claim 2 is characterized in that: The formula of the first objective function J1, the power balance of the hybrid electrolysis hydrogen production system, the ramp rate of the hydrogen production module, and the constraints of the power operation range of the hydrogen production module are as follows: Power balance constraints of hybrid electrolysis hydrogen production system: P res (t)+P sc (t) = P hes (t), The ramp rate constraint of the hydrogen production module is: The power operating range constraint of the hydrogen production module: P hesmin ≤P hes (t)≤P hesmax , Among them, 0-t f represents the time period during which the hydrogen production module operates, P hes (t) represents the input power of the hydrogen production module, SOC init Indicates the initial state of charge of the energy buffer module, SOC end represents the final state of charge of the energy buffer module, ω represents the weight of the state of charge conversion energy, P res (t) represents the total available power of the electrical energy, P sc (t) represents the input / output power of the energy buffer module, P hes (t) represents the input power of the hydrogen production module, P hesmin represents the lower limit of the operating power of the hydrogen production module, P hesmax Indicates the upper limit of the operating power of the hydrogen production module, Indicates that the hydrogen production module is at sampling time T s The fluctuation of internal input power, that is, the climbing rate.

4. The energy management method based on the dynamic characteristics of the hybrid electrolysis hydrogen production system according to claim 2 is characterized in that: The formula of the first affine function constructed based on the dynamic response capability of the energy buffer module is as follows: P sc (t)=A1(t)P res (t)-A2(t)avg(P res (t)), Where A1(t) represents the first gain coefficient, and A1(t)∈[0.6,1], A2(t) represents the first base coefficient, avg(P res (t)) represents the mean value of all available power of the electrical energy, P sc (t) represents the input / output power of the energy buffer module.

5. The energy management method based on the dynamic characteristics of the hybrid electrolysis hydrogen production system according to claim 2 is characterized in that: The steps of allocating the high-frequency component of the input power of the hydrogen production module to the high-performance electrolyzer in the hydrogen production module to prepare hydrogen according to the dynamic response characteristics of the electrolyzer, and allocating the low-frequency component of the input power of the hydrogen production module to the ordinary electrolyzer in the hydrogen production module to prepare hydrogen include: Establishing a second objective function based on the hydrogen production of the high-performance electrolyzer and the ordinary electrolyzer; Constructing a second affine function according to the dynamic response capability of the high-performance electrolyzer to constrain the second objective function; Minimizing the second objective function to maximize the total hydrogen production of the hydrogen production module, and calculating the single hydrogen production of the high-performance electrolyzer and the ordinary electrolyzer; The power distribution of the high-performance electrolyzer and the ordinary electrolyzer in the hydrogen production module is calculated based on the single-cell hydrogen production of the high-performance electrolyzer and the ordinary electrolyzer and the number of single-cells configured for the high-performance electrolyzer and the ordinary electrolyzer.

6. The energy management method based on the dynamic characteristics of the hybrid electrolysis hydrogen production system according to claim 5 is characterized in that: The step of calculating the power distribution of the high-performance electrolyzer and the ordinary electrolyzer in the hydrogen production module according to the monomer hydrogen production of the high-performance electrolyzer and the ordinary electrolyzer and the number of monomers configured by the high-performance electrolyzer and the ordinary electrolyzer comprises: The hydrogen production of the high-performance electrolyzer is calculated based on the number of monomers and the hydrogen production of the monomers of the high-performance electrolyzer, and the hydrogen production of the ordinary electrolyzer is calculated based on the number of monomers and the hydrogen production of the monomers of the ordinary electrolyzer; Obtaining input power of the high-performance electrolyzer and the ordinary electrolyzer according to the hydrogen production of the high-performance electrolyzer and the ordinary electrolyzer; Among them, the hydrogen production of the high-performance electrolyzer and the ordinary electrolyzer is linearly correlated with their corresponding input power, and the input power of the high-performance electrolyzer is the high-frequency component of the input power of the hydrogen production module, and the input power of the ordinary electrolyzer is the low-frequency component of the input power of the hydrogen production module.

7. The energy management method based on the dynamic characteristics of the hybrid electrolysis hydrogen production system according to claim 6 is characterized in that: The formula of the second objective function J2 and its related constraints are as follows: The power operating range constraint of the common electrolyzer is: P aemin ≤P ae (t)≤P aemax , The power operating range constraint of the high-performance electrolyzer is: 0≤P pe (t)≤P pemax , The power balance constraint of the hydrogen production module: P hes (t) = P ae (t)+P pe (t), And P ae (t) = x ae P aeb (t), P pe (t) = x pe P peb (t), The constraints of the ramp rate of the common electrolyzer are: Constraints on the ramp rate of the high performance electrolyser: Among them, β H Indicates the unit price of hydrogen sold, 0-t f The time period during which the hydrogen production module operates, x ae represents the number of monomers configured in the common electrolytic cell, x pe Indicates the number of monomers configured in the high-performance electrolyzer, n aeb (t) represents the single hydrogen production of the common electrolyzer, n peb (t) represents the single hydrogen production of the high performance electrolyzer, P aemin represents the lower limit of the operating power of the common electrolytic cell, P aemax represents the upper limit of the operating power of the common electrolytic cell, P pemax represents the upper limit of the operating power of the high performance electrolyzer, P hes (t) represents the input power of the hydrogen production module, P ae (t) represents the input power of the conventional electrolytic cell, P pe (t) represents the input power of the high performance electrolyzer, P aeb (t) represents the single input power of the conventional electrolytic cell, P peb (t) represents the single input power of the high performance electrolyzer, Indicates that the common electrolytic cell monomer is at sampling time T s The fluctuation of the internal input power, that is, the ramp rate, Indicates that the high performance electrolyzer monomer is at sampling time T s The fluctuation of internal input power, that is, the climbing rate.

8. The energy management method based on the dynamic characteristics of the hybrid electrolysis hydrogen production system according to claim 5 is characterized in that: The formula of the second affine function constructed based on the dynamic response capability of the high-performance electrolyzer is as follows: P pe (t)=B1(t)P hes (t)-B2(t)min(P hes (t)), Among them, B1(t)∈[0.6,1], B2(t) represents the second basis coefficient, min(P hes (t)) represents the minimum value of the input power of the hydrogen production module, P pe (t) represents the input power of the high performance electrolyzer.

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