ALK-PEM electrolytic cell hydrogen production system power distribution method and system

Abstract

The invention belongs to the technical field of renewable energy hydrogen production, and particularly relates to a power distribution method and system for an ALK-PEM electrolytic cell hydrogen production system, and the method comprises the steps: obtaining the operation characteristics of an ALK electrolytic cell and a PEM electrolytic cell, and constructing an ALK-PEM electrolytic cell combined hydrogen production system; based on the starting and stopping characteristics of the electrolytic cell of the constructed ALK-PEM electrolytic cell combined hydrogen production system, considering the second-level starting and stopping characteristics of the PEM electrolytic cell, and determining the operation mode of the electrolytic cell of the hydrogen production system by adopting an electrolytic cell array double-layer rotation operation mode; according to the determined operation mode of the electrolytic cell, an optimal power distribution model considering starting and stopping of the electrolytic cell is constructed by taking the maximum net income of the hydrogen production system of the mixed electrolytic cell as a target; the constructed optimal power distribution model is solved, and power distribution of the ALK-PEM electrolytic cell hydrogen production system is completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production from renewable energy, and in particular relates to a power distribution method and system for an ALK-PEM electrolyzer hydrogen production system. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the increasing depletion of fossil energy and the increasing global warming problem, the electrolysis of water to produce hydrogen through new energy sources such as wind power and photovoltaic power generation has become one of the important means of low-carbon transformation in the energy field. At present, the more mature technologies for hydrogen production by electrolysis of water mainly include alkaline (ALK) electrolysis and proton exchange membrane (PEM) electrolysis; among them, the ALK electrolyzer has a large single capacity and low cost, but its dynamic response speed is slow and its adaptability to the volatility of renewable energy is poor, which has certain disadvantages; the PEM electrolyzer has high hydrogen production efficiency and can respond to fluctuating power sources in seconds, which can effectively cope with the volatility and intermittent characteristics of renewable energy generation, but its cost is relatively high. ALK-PEM combined hydrogen production can complement each other and significantly improve the hydrogen production system's ability to absorb renewable energy. Therefore, how to fully tap the potential of combined hydrogen production based on the second-level operation characteristics of ALK-PEM and formulate the optimal power allocation strategy for the system is a key way to improve the level of new energy absorption.

[0004] At present, ALK electrolyzers occupy a mainstream position in off-grid hydrogen production systems due to their mature technology, low cost, and relatively simple operation and maintenance. Relevant literature proposes an operation strategy for a new energy hydrogen production system based on the start-stop characteristics of alkaline electrolyzers, which realizes the coordinated operation of multiple electrolyzers and reduces the number of start-stop times of the electrolyzers; relevant studies consider the efficiency characteristics and start-stop characteristics of alkaline electrolyzers, and propose a switching scheduling strategy for multiple ALK electrolyzers for off-grid wind power hydrogen production based on the Pelican optimization algorithm; relevant scholars consider the frequent operation of electrolyzer switches caused by the volatility of wind power, and propose a multi-objective rolling optimization control strategy based on wind power output prediction; to balance the operating status of each electrolyzer, relevant studies propose an ALK electrolyzer array optimization control strategy based on the rotation idea; the combined operation characteristics of multiple electrolyzers can be analyzed, and a double-layer rotation coordinated operation strategy for multiple ALK electrolyzers is proposed, but the existing technology does not give the corresponding precise mathematical expression; in summary, the existing relevant technologies have verified that the new energy absorption capacity can be effectively improved by considering the start-stop characteristics and efficiency characteristics of ALK electrolyzers, but the response speed is slow and the operation efficiency needs to be improved.

[0005] PEM electrolyzers have shown strong competitiveness with advantages such as high efficiency, fast response, high current density, low operating temperature and high-purity hydrogen, and have become a research focus in the field of electrolytic hydrogen production. The efficient consumption of new energy can be promoted by optimizing the operation of electric-hydrogen hybrid energy storage considering the dynamic efficiency characteristics of PEM electrolyzers. Considering the operational safety characteristics and the pressure characteristics of the electrolyzer, related studies have proposed an optimized operation method for PEM electrolysis hydrogen production systems based on pressure control. The relationship between the key factors affecting the electrolyzer is analyzed, and the power-temperature adaptive control optimization strategy is used to improve the hydrogen production efficiency of the system. Taking into account the power-efficiency characteristics of PEM, low-carbon optimization of the coordination of green hydrogen and blue hydrogen in the integrated energy system is carried out. However, related studies have verified that PEM electrolyzers have better absorption capacity for intermittent new energy and higher hydrogen production efficiency, but have not comprehensively considered the characteristics of PEM electrolyzers to formulate reasonable and effective power allocation strategies.

[0006] In summary, the performance of ALK and PEM electrolyzers in green electricity hydrogen production was explored, but the different characteristics of ALK and PEM electrolyzers were not considered for coordinated hydrogen production. At the same time, the start-stop strategy was relatively rough, which may lead to energy waste and fail to give full play to the advantages of electrolyzers, limiting the flexibility and economy of hydrogen production. Considering the different operating characteristics of the two types of electrolyzers, the hydrogen production method that gives full play to their respective advantages provides a new idea for electrolytic hydrogen production technology in dealing with the volatility of renewable energy. Existing technologies can verify that ALK-PEM combined hydrogen production can significantly improve the system's hydrogen production efficiency and the utilization rate of wind and solar resources, but the scheduling time scale is roughly hourly or 5 minutes. This coarse-grained expression is easy to build and solve the model, but in fact, the PEM electrolyzer has a second-level response characteristic and can be started and stopped in seconds. If it is not finely characterized, it is easy to lose part of the scheduling space, resulting in insufficient exploration of its hydrogen production flexibility. Summary of the invention

[0007] To solve the above problems, the present invention proposes a power allocation method and system for an ALK-PEM electrolyzer hydrogen production system, taking into account the second-level start and stop characteristics of the PEM electrolyzer, and comprehensively considering the power-efficiency characteristics, start and stop characteristics of ALK and PEM electrolyzers and the second-level response speed characteristics of the PEM electrolyzer, so as to fully tap the hydrogen production potential of its fast response flexibility resources, thereby expanding the dispatchable space and improving the hydrogen production efficiency.

[0008] According to some embodiments, a first solution of the present invention provides a power allocation method for an ALK-PEM electrolyzer hydrogen production system, which adopts the following technical solution:

[0009] A power distribution method for an ALK-PEM electrolyzer hydrogen production system, comprising:

[0010] Obtain the operating characteristics of ALK electrolyzer and PEM electrolyzer, and build an ALK-PEM electrolyzer combined hydrogen production system;

[0011] Based on the start-stop characteristics of the electrolyzer of the constructed ALK-PEM electrolyzer combined hydrogen production system, the operation mode of the electrolyzer of the hydrogen production system is determined by adopting the double-layer rotation operation mode of the electrolyzer array, taking into account the second-level start-stop characteristics of the PEM electrolyzer.

[0012] According to the determined electrolyzer operation mode, the optimal power allocation model taking into account the start and stop of the electrolyzer is constructed with the goal of maximizing the net profit of the hybrid electrolyzer hydrogen production system;

[0013] Solve the constructed optimal power allocation model and complete the power allocation of the ALK-PEM electrolyzer hydrogen production system.

[0014] As a further technical limitation, the double-layer rotation operation mode of the electrolytic cell array adopted is that the upper layer adopts the principle of start-first-shutdown and start-last-shutdown to balance the working time of different electrolytic cells, and the lower layer performs array rotation operation according to the operating conditions of the electrolytic cell single hydrogen production.

[0015] Furthermore, the operating conditions of the electrolyzer unit for hydrogen production include at least a shutdown operating state, a high-efficiency operating state, a rated operating state, an overload operating state and a fluctuating operating state.

[0016] As a further technical limitation, the objective function of the optimal power allocation model considering the start and stop of the electrolyzer is: Where F is the net income of the hybrid electrolyzer hydrogen production system; The revenue from selling hydrogen for the hybrid electrolyzer hydrogen production system; C op is the operating cost of ALK electrolyzer and PEM electrolyzer; C on is the operating cost of the hybrid electrolyzer hydrogen production system; C off is the shutdown cost of the hybrid electrolyzer hydrogen production system; C curt Penalty costs for wind and solar curtailment in hybrid electrolyzer hydrogen production systems.

[0017] As a further technical limitation, the constraints of the constructed optimal power allocation model taking into account the start and stop of the electrolyzer include at least power balance constraints, ALK-PEM electrolyzer output constraints, ALK electrolyzer fluctuating power constraints, PEM electrolyzer fluctuating power constraints, ALK-PEM electrolyzer minimum start and stop time constraints, ALK-PEM electrolyzer array operation constraints and ALK-PEM electrolyzer upper array rotation start and stop constraints.

[0018] As a further technical limitation, the operating characteristics of the ALK electrolyzer and the PEM electrolyzer obtained include at least the power-efficiency curve, electrolyzer single cell capacity, electrolyzer regulation performance, operating cost, start-stop characteristics and second-level response characteristics.

[0019] According to some embodiments, the second solution of the present invention provides a power distribution system for an ALK-PEM electrolyzer hydrogen production system, which adopts the following technical solution:

[0020] A power distribution system for an ALK-PEM electrolyzer hydrogen production system, comprising:

[0021] An acquisition module configured to acquire operating characteristics of the ALK electrolyzer and the PEM electrolyzer and construct an ALK-PEM electrolyzer combined hydrogen production system;

[0022] A determination module, which is configured to determine the operation mode of the electrolyzer of the hydrogen production system by adopting a double-layer rotation operation mode of the electrolyzer array based on the start-stop characteristics of the electrolyzer of the constructed ALK-PEM electrolyzer combined hydrogen production system, taking into account the second-level start-stop characteristics of the PEM electrolyzer;

[0023] A construction module is configured to construct an optimal power allocation model taking into account the start and stop of the electrolyzer according to the determined electrolyzer operation mode and with the goal of maximizing the net profit of the hybrid electrolyzer hydrogen production system;

[0024] A solution module is configured to solve the constructed optimal power allocation model to complete the power allocation of the ALK-PEM electrolyzer hydrogen production system.

[0025] According to some embodiments, a third solution of the present invention provides a computer-readable storage medium, which adopts the following technical solution:

[0026] A computer-readable storage medium stores a program thereon, which, when executed by a processor, implements the steps in a power distribution method for an ALK-PEM electrolyzer hydrogen production system as described in the first embodiment of the present invention.

[0027] According to some embodiments, a fourth solution of the present invention provides an electronic device, which adopts the following technical solution:

[0028] An electronic device comprises a memory, a processor and a program stored in the memory and running on the processor, wherein when the processor executes the program, the steps in a power distribution method for an ALK-PEM electrolyzer hydrogen production system as described in the first embodiment of the present invention are implemented.

[0029] According to some embodiments, a fifth solution of the present invention provides a computer program product, which adopts the following technical solution:

[0030] A computer program product includes software codes, wherein the program in the software codes executes the steps in the power distribution method of an ALK-PEM electrolyzer hydrogen production system as described in the first embodiment of the present invention.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention takes into account the second-level start and stop characteristics of the PEM electrolyzer, and comprehensively considers the power-efficiency characteristics, start and stop characteristics of ALK and PEM electrolyzers, and the second-level response speed characteristics of the PEM electrolyzer, so as to fully tap the hydrogen production potential of its fast response flexibility resources, thereby expanding the dispatchable space and improving the hydrogen production efficiency.

[0033] The present invention proposes an electrolyzer mathematical model that takes into account the second-level start-stop characteristics of PEM, draws on the start-stop expression concept of traditional thermal power units, and combines the double-layer array rotation operation mode of hybrid electrolyzers to finely express the start-stop constraints of ALK-PEM electrolyzers and the rotation constraints of hybrid electrolyzer arrays, so as to fully tap the flexibility of the combined hydrogen production system and improve the overall service life of the system.

[0034] The present invention proposes the optimal power allocation of ALK-PEM electrolyzer, comprehensively considering key factors such as the power-efficiency curves, regulation performance and capacity of the two electrolyzers, and at the same time, based on the segmented intervals of hydrogen production power, formulates the power allocation strategy for the highest efficiency operation mode of ALK-PEM electrolyzer and a refined power dynamic adjustment mechanism taking into account the characteristics of the electrolyzer, so as to further improve the overall efficiency of the electrolyzer system while ensuring the maximization of new energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0036] Figure 1 This is a flow chart of a power allocation method for an ALK-PEM electrolyzer hydrogen production system according to an embodiment of the present invention;

[0037] Figure 2 This is an architecture diagram of an ALK-PEM electrolysis hydrogen production system according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the structure of the ALK electrolytic cell in the first embodiment of the present invention;

[0039] Figure 4 The power-efficiency curve of the ALK electrolyzer in the first embodiment of the present invention;

[0040] Figure 5This is a schematic diagram of the structure of a PEM electrolyzer in Embodiment 1 of the present invention;

[0041] Figure 6 The power-efficiency curve of the PEM electrolyzer in the first embodiment of the present invention;

[0042] Figure 7 A flow chart of a power allocation strategy for a highest efficiency operation mode according to an embodiment of the present invention;

[0043] Figure 8 This is a schematic diagram of the rotational startup operation mode of the upper array of the electrolytic cell in the first embodiment of the present invention;

[0044] Fig. 9 This is a schematic diagram of the rotational shutdown operation mode of the upper array of the electrolytic cell in the first embodiment of the present invention;

[0045] Fig.10 This is a schematic diagram of the rotation operation mode of the lower array of the electrolytic cell in the first embodiment of the present invention;

[0046] Fig.11 The wind and solar power prediction curve diagram for each typical day in the first embodiment of the present invention;

[0047] Fig.12 This is a schematic diagram of wind and solar power output and electrolysis hydrogen production power under different power allocation schemes in an embodiment of the present invention;

[0048] Fig.13 This is a comparison chart of hydrogen production power at the second level and the 5-minute level in Example 1 of the present invention;

[0049] Fig.14 This is a diagram of wind and solar power output and electrolyzer array operation status in the first embodiment of the present invention;

[0050] Fig.15 This is a diagram of the rotation operation status of the upper array of the ALK electrolytic cell in the first embodiment of the present invention;

[0051] Fig.16 This is a diagram showing the rotation operation status of the lower array of the PEM electrolyzer in the first embodiment of the present invention;

[0052] Fig.17 This is a structural block diagram of a power distribution system of an ALK-PEM electrolyzer hydrogen production system in Example 2 of the present invention. DETAILED DESCRIPTION

[0053] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0054] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0055] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0056] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0057] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present invention can be determined according to specific circumstances, and they cannot be understood as limitations on the present invention.

[0058] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0059] Embodiment 1

[0060] Embodiment 1 of the present invention introduces a power distribution method for an ALK-PEM electrolyzer hydrogen production system.

[0061] like Figure 1 A power distribution method for an ALK-PEM electrolyzer hydrogen production system is shown, comprising:

[0062] Obtain the operating characteristics of ALK electrolyzer and PEM electrolyzer, and build an ALK-PEM electrolyzer combined hydrogen production system;

[0063] Based on the start-stop characteristics of the electrolyzer of the constructed ALK-PEM electrolyzer combined hydrogen production system, the operation mode of the electrolyzer of the hydrogen production system is determined by adopting the double-layer rotation operation mode of the electrolyzer array, taking into account the second-level start-stop characteristics of the PEM electrolyzer.

[0064] According to the determined electrolyzer operation mode, the optimal power allocation model taking into account the start and stop of the electrolyzer is constructed with the goal of maximizing the net profit of the hybrid electrolyzer hydrogen production system;

[0065] Solve the constructed optimal power allocation model and complete the power allocation of the ALK-PEM electrolyzer hydrogen production system.

[0066] This embodiment aims at how to improve the utilization rate of renewable energy power generation and the efficiency of hydrogen production in hybrid electrolyzers during green electricity hydrogen production. Figure 2 The ALK-PEM electrolyzer combined hydrogen production system architecture shown in the figure is as follows; specifically, wind power and photovoltaic power are used as water electrolysis power sources to provide energy support for the hydrogen production system; secondly, in the first stage, the power-efficiency curves, regulation performance, operating costs, single-cell capacity, and the second-level start-stop and response characteristics of the two electrolyzers are comprehensively considered, and the power allocation strategy is formulated according to the optimal power-efficiency operation mode of the ALK-PEM hybrid electrolyzer; then, in the second stage, the mathematical model of the operation characteristics of the ALK-PEM electrolyzer is derived for the five operating states of the electrolyzer, namely, shutdown, highest efficiency operation, rated operation, overload operation, and fluctuating power, and the operating state of each electrolyzer is determined on this basis. This two-stage allocation strategy fully considers the economic efficiency and dynamic operating characteristics of each device, and realizes the complementary advantages of ALK and PEM electrolyzers; finally, a hybrid electrolyzer double-layer array rotation operation mode is adopted, the upper layer decides the start-stop sequence of the electrolyzer, and the lower layer rotates the electrolyzer sequence, extending the overall service life of the ALK-PEM electrolyzer system. The developed optimal power allocation strategy for ALK-PEM electrolyzer combined hydrogen production significantly improves the consumption level of wind and solar energy and hydrogen production efficiency by efficiently converting renewable energy into clean hydrogen energy.

[0067] In this embodiment, the structure of the ALK electrolytic cell is as follows: Figure 3 As shown, it consists of electrodes, electrolyte and diaphragm. The reaction expression of the electrolysis process is Combined with the electrochemical model parameters of the alkaline electrolyzer shown in Table 1, the empirical equation can be obtained:

[0068]

[0069] η ALK =η ALK,U η ALK,F (3)

[0070]

[0071] Among them, η ALK,U is the voltage efficiency of ALK electrolyzer; U ALK,th and U ALK,revare the thermoneutral voltage and reversible voltage of the ALK electrolyzer, respectively; r1, r2, d1 and d2 are constants related to the ohmic resistance of the electrolyzer, respectively; s, t1, t2 and t3 are constants related to the reaction overpotential, respectively; T ALK is the rated operating temperature of the ALK electrolyzer; P and I are the pressure and current of the electrolyzer, respectively; A is the electrode surface area of ​​the electrolyzer; η ALK,F is the Faradaic efficiency of the ALK electrolyzer; f 11 、f 12 、f 21 and f 21 is a constant related to Faraday efficiency; η ALK is the operating efficiency of the ALK electrolyzer; is the per-unit value of the operating power of the ALK electrolyzer; M is the number of electrolyzer chambers; P ALK,e It is the rated power of a single ALK electrolyzer.

[0072] Table 1 Parameters of electrochemical model of alkaline electrolyzer

[0073]

[0074]

[0075] This embodiment takes a 5MW ALK electrolyzer as an example. According to formula (1), formula (2), formula (3) and formula (4), it can be obtained as follows: Figure 4 The power-efficiency curve of the ALK electrolyzer shown in the figure; when the power input to the ALK electrolyzer is low, the operating efficiency of the electrolyzer increases significantly with the increase of the input power; when When This is because with the increase of input power, the current density increases, resulting in an increase in overpotential, and more electrical energy is converted into thermal energy, resulting in a decrease in hydrogen production efficiency.

[0076] The hydrogen production power of the ALK electrolyzer increases first and then decreases with the increase of input power, and the hydrogen production efficiency reaches a maximum at 25% of the rated power. Therefore, this embodiment sets the highest efficiency point power of the ALK electrolyzer to 25% of the rated power.

[0077] In this embodiment, the structure of the PEM electrolyzer is as follows: Figure 5 As shown, the chemical reaction of the electrolysis process is Combined with the electrochemical model of the PEM electrolyzer shown in Table 2, the operating efficiency η of the PEM electrolyzer can be obtained PEM The input power per unit value The relationship equation is

[0078]

[0079] η PEM =η PEM,U η PEM,I (7)

[0080]

[0081] Among them, η PEM,U is the voltage efficiency of the PEM electrolyzer; U PEM,th is the thermal neutral voltage of the PEM electrolyzer; R is the gas constant; T PEM is the rated operating temperature of the PEM electrolyzer; α A is the anode charge transfer coefficient; z is the stoichiometric coefficient; F is the Faraday constant; i and i A are the electrolytic cell current density and the anode conversion current density, respectively; γ A is the anode activation area ratio; e A and e C are the thickness of the anode plate and cathode plate respectively; σ A and σ C are the conductivity of the anode plate and the cathode plate respectively; e M is the thickness of the proton exchange membrane; κ is the conductivity of the electrolyte; η PEM,I is the dynamic current efficiency of the PEM electrolyzer; D H is the diffusion coefficient of hydrogen; S H is the solubility coefficient of hydrogen; ΔP is the hydrogen partial pressure difference on both sides of the proton exchange membrane; η PEM is the operating efficiency of the PEM electrolyzer; U is the per unit value of the operating power of the PEM electrolyzer; PEM,e and i e are the rated voltage and rated current density of the PEM electrolyzer respectively.

[0082] Table 2 PEM electrolyzer electrochemical model parameters

[0083]

[0084] Taking a 1MW PEM electrolyzer as an example, according to formula (5), formula (6), formula (7) and formula (8), we can get: Figure 6 The power-efficiency curve of the PEM electrolyzer is shown in The hydrogen production efficiency is the highest when The overall trend and reasons for the power-efficiency curve of the PEM electrolyzer are similar to those of the alkaline electrolyzer. However, due to the higher current density and larger load range of the PEM electrolyzer, its initial rise speed is faster and its working range is wider.

[0085] Similarly, the hydrogen production efficiency of the PEM electrolyzer reaches its maximum at 10% of the rated power, so in this embodiment, the maximum efficiency point power of the PEM electrolyzer is set to 10% of the rated power.

[0086] The frequent start and stop operation of the electrolyzer will cause a certain degree of impact and wear on the electrolysis equipment, affecting the performance and reliability of the equipment. This will not only reduce the efficiency and quality of hydrogen production, but may also increase the maintenance cost and downtime of the equipment.

[0087] The electrolyzer needs to go through the steps of heating and pressurizing from the shutdown state to the normal working state. During the startup process, the electrolyzer does not work and does not produce hydrogen. The startup of the electrolyzer is divided into cold start and hot start. The temperature change of frequent cold start will reduce the life of the electrolyzer sealing material. Therefore, in reality, most electrolyzers are avoided from frequent cold starts. In addition, the time required for the actual electrolyzer to drop from the working state temperature to room temperature is too long, about ten hours, so this embodiment only considers the hot start state. Different types of electrolyzers require different times for hot start. ALK electrolyzers require several minutes, while PEM electrolyzers only require a few seconds. The time required for the shutdown process of the two electrolyzers is different from that of the startup. It only takes a few milliseconds to reduce the power to zero. Therefore, this embodiment ignores the shutdown process time of the two electrolyzers. This embodiment draws on the expression concept of start-stop of traditional thermal power units, and derives the day-ahead scheduling start-stop constraints of the two electrolyzers as follows:

[0088] Assume T ALK,on is the minimum startup time of the ALK electrolyzer, the corresponding minimum startup time constraint can be expressed as:

[0089] 1) t>T ALK,on When ALK electrolyzer m is started at time t, the conditions that must be met are: the continuous shutdown time before time t is greater than or equal to the minimum startup time, that is:

[0090]

[0091] in, It is a 0-1 variable indicating the start and stop status of ALK electrolyzer m at time t.

[0092] 2)1<t≤T ALK,on When ALK electrolyzer m is in shutdown state at the initial moment, the conditions that must be met for its startup at moment t are: the sum of the continuous shutdown time before moment t and the initial shutdown time is greater than or equal to the minimum startup time, that is:

[0093]

[0094] in, It is the downtime time of ALK electrolyzer m at the initial moment.

[0095] 3)1≤t≤T ALK,onWhen ALK electrolyzer m is in the on state at the initial moment, it is stipulated that ALK electrolyzer m cannot be turned on at time t, that is:

[0096]

[0097] 4) When t=1, if the ALK electrolyzer m is in shutdown state at the initial moment, the conditions that must be met for its startup at moment t are: the continuous shutdown time before moment t is greater than or equal to the minimum startup time, that is:

[0098]

[0099] Similarly, the minimum startup time constraint of PEM electrolyzer is:

[0100] 1) t>T PEM,on When the PEM electrolyzer n stops running at time t, the condition that must be met is: the continuous shutdown time before time t is greater than or equal to the minimum startup time, that is:

[0101]

[0102] in, is a 0-1 variable indicating the start and stop status of PEM electrolyzer n at time t; T PEM,on is the minimum startup time of the PEM electrolyzer.

[0103] 2)1<t≤T PEM,on When PEM electrolyzer n is in shutdown state at the initial moment, the conditions that must be met for its startup at moment t are: the sum of the continuous shutdown time before moment t and the initial shutdown time is greater than or equal to the minimum startup time, that is:

[0104]

[0105] in, is the downtime of PEM electrolyzer n at the initial moment.

[0106] 3)1≤t≤T PEM,on When PEM electrolyzer n is in the on state at the initial moment, it is stipulated that PEM electrolyzer n cannot be turned on at time t, that is:

[0107]

[0108] 4) When t=1, if the PEM electrolyzer n is in shutdown state at the initial moment, the conditions that must be met for its startup at moment t are: the continuous shutdown time before moment t is greater than or equal to the minimum startup time, that is:

[0109]

[0110] The startup costs of the two electrolyzers can be expressed as:

[0111]

[0112] Among them, C on is the startup cost of the two electrolyzers; c ALK,on and c PEM,on are the startup cost coefficients for ALK and PEM electrolyzers, respectively.

[0113] The downtime costs of the two electrolyzers are shown in formula (18):

[0114]

[0115] Among them, C off is the downtime cost of the two electrolyzers; c ALK,off and c PEM,off are the shutdown cost coefficients for ALK and PEM electrolyzers, respectively.

[0116] Taking into account the power-efficiency curves of the ALK electrolyzer and the PEM electrolyzer, the adjustment performance limitations and the second-level start-stop characteristics of the PEM electrolyzer, and in order to obtain the best hydrogen production effect, this embodiment is set to give priority to the power allocation of the ALK electrolyzer with lower operating cost, slower response speed, larger capacity configuration and poorer adjustment performance, and utilize the rapid response characteristics of the PEM electrolyzer to absorb the remaining wind and solar power fluctuations, so as to reduce the frequent start-stop of the ALK and PEM electrolyzers and reduce the amount of wind and solar power abandonment, thereby increasing the flexibility of the hydrogen production system.

[0117] In order to ensure the safety of the electrolytic hydrogen production system and the high efficiency of hydrogen production, this embodiment proposes a refined interval power dynamic adjustment mechanism to start the ALK electrolyzer at the minimum starting power point P ALK,min , Maximum efficiency power point P ALK,h and rated power point P ALK,e The hydrogen production power is divided into 4 sections. Similarly, the PEM electrolyzer is started at the minimum power point P PEM,min , Maximum efficiency power point P PEM,h , rated power point P PEM,e And overload power point 1.2P PEM,e The hydrogen production power is divided into five intervals as segmentation points. According to the characteristics of different intervals, a hydrogen production power allocation strategy that helps improve efficiency is formulated to enable the system to approach the optimal operating state. In order to expand the scheduling space, further improve the absorption capacity of new energy, and reduce the amount of wind and solar power abandonment, this embodiment reserves one ALK electrolyzer and one PEM electrolyzer as slack capacity to cope with wind and solar power fluctuations.

[0118] In order to extend the service life of the electrolyzer and ensure the safe and stable operation of the electrolyzer, this embodiment adopts a double-layer rotation operation mode of the electrolyzer array to ensure the consistency of the monomers between groups. Taking into account the start-stop characteristics of the proposed ALK-PEM electrolyzer, the upper layer adopts the principle of start-up first and then shutdown, and start-up last and then shutdown, so that the working time of each electrolyzer is kept as balanced as possible; the lower layer, based on the proposed refined power dynamic adjustment mechanism, divides the hydrogen production conditions of the electrolyzer monomer into five types: shutdown, high efficiency, rated, overload and fluctuation, and performs array rotation operation on the electrolyzers in the operating condition to extend the service life of the overall system.

[0119] This embodiment proposes Figure 7 The power allocation strategy for the most efficient operation mode of the ALK-PEM electrolyzer combined hydrogen production system shown in the figure, where P Wind,PV Contribute to the scenery, P emax is the overload capacity of the electrolyzer system, P ALK and P PEM are the capacities of ALK and PEM electrolyzers, respectively, ALK,h is the power of a single ALK electrolyzer operating at the highest efficiency point, P PEM,h is the power of a single PEM electrolyzer operating at the highest efficiency point, N ALK and N PEM are the number of ALK and PEM electrolyzer arrays respectively.

[0120] Taking into account the power-efficiency characteristics of the ALK electrolyzer and the PEM electrolyzer and the wide load characteristics of the PEM electrolyzer, this embodiment sets the overload capacity of the ALK-PEM electrolyzer system to P emax =P ALK +1.2P PEM , the system rated capacity is P e =P ALK +P PEM , the system's highest efficiency point capacity is P h =P ALK,h N ALK +P PEM,h N PEM The specific allocation strategy is as follows:

[0121] 1) When the wind and solar power output is greater than or equal to the electrolyzer system overload capacity (P Wind,PV ≥P emax ) when setting the ALK electrolyzer to rated power P ALK Operation, PEM electrolyzer with overload power 1.2P PEM run;

[0122] 2) When the wind and solar output is between the rated capacity and overload capacity of the electrolyzer system (P e ≤P Wind,PV <Pemax ), the power distribution to the ALK electrolyzer is prioritized, with the rated power P ALK Running, residual power P Wind,PV -P ALK The PEM electrolyzer consumes the waste.

[0123] 3) When the wind and solar output is between the maximum efficiency point capacity and the rated capacity of the electrolyzer system (P h ≤P Wind,PV <P e ), the ALK electrolyzer and the PEM electrolyzer distribute input power according to the capacity ratio, that is, the ALK electrolyzer distributes power PEM electrolyser power distribution

[0124]

[0125] 4) When the wind and solar power output is less than the maximum efficiency point capacity of the electrolyzer system When ALK electrolyzer and PEM electrolyzer distribute input power according to the capacity ratio of the highest efficiency point, that is, ALK electrolyzer distributes power PEM electrolyser power distribution

[0126]

[0127] To N ALK The total power allocated to the ALK electrolyzer array in period t is The average power of the electrolyzer is The minimum starting power of a single ALK electrolyzer is P ALK,min , then the operation optimization strategy is formulated according to different operation intervals as follows:

[0128] 1) When , all ALK electrolyzers stop running, which is expressed as:

[0129]

[0130] in, and are the number of ALK electrolyzers operating at the highest efficiency point power and rated power in period t, respectively; is a 0-1 variable indicating the operating status of the ALK electrolyzer that bears fluctuating power during period t; is the actual total hydrogen production power of the ALK electrolyzer during period t; It is the fluctuating power borne by a single ALK electrolyzer during period t.

[0131] 2) and hour, Each ALK electrolyzer operates at the highest efficiency point power. Each ALK electrolyzer bears fluctuating power, expressed as:

[0132]

[0133] 3) hour, Each ALK electrolyzer operates at the highest efficiency point power. The unit is running at rated power. The station bears the fluctuating power, which is expressed as:

[0134]

[0135] 4) When , all ALK electrolyzers are operated at rated power, expressed as:

[0136]

[0137] The ALK electrolyzer array also needs to meet the following operating constraints:

[0138]

[0139] in, is the number of ALK electrolyzers that are out of service during period t.

[0140] Similarly, for PEM electrolyzers, let the number of electrolyzer arrays be N. PEM , where there is one electrolyzer that bears the fluctuating power, and the total power allocated to the PEM electrolyzer at time t is The average power of the electrolyzer is The minimum starting power of a single PEM electrolyzer is P PEM,min , then the operation optimization strategy of PEM electrolyzer can be expressed as:

[0141] 1) When , all PEM electrolyzers stop running, which is expressed as:

[0142]

[0143] in, and are the number of PEM electrolyzers operating at the highest efficiency point power, rated power, and overload power during period t, respectively; is a 0-1 variable indicating the operating status of the PEM electrolyzer that bears fluctuating power during period t; It refers to the actual total hydrogen production power of the PEM electrolyzer during period t; It is the fluctuating power borne by a single PEM electrolyzer during period t.

[0144] 2) and hour, The PEM electrolyzers are operated at the highest efficiency point power. Each PEM electrolyzer bears fluctuating power, expressed as:

[0145]

[0146] 3) hour, The PEM electrolyzers are operated at the highest efficiency point power. The unit is running at rated power. Each PEM electrolyzer bears fluctuating power, expressed as:

[0147]

[0148] Among them, P PEM,e It is the rated power of a single PEM electrolyzer.

[0149] 4) hour, The PEM electrolyzer is operated at rated power. The station is running at overload power. The station bears the fluctuating power, which is expressed as:

[0150]

[0151] 5) When , all PEM electrolyzers operate at overload power, expressed as:

[0152]

[0153] The PEM electrolyzer array also needs to meet the following operating constraints:

[0154]

[0155] in, is the number of PEM electrolyzers that are out of service during period t.

[0156] Taking into account the refined interval power regulation mechanism taking into account the characteristics of the electrolyzer and the proposed ALK-PEM electrolyzer start-stop characteristics, the two electrolyzer monomers include one electrolyzer in each interval section for absorbing the fluctuating power of wind and solar power. In order to balance the operating time of each electrolyzer in five different operating conditions during the total operating cycle, including shutdown, operation at the highest efficiency point, rated power operation, overload power operation, and fluctuating power operation, this embodiment adopts a hybrid electrolyzer array double-layer rotation operation mode to extend the overall service life of the electrolyzer system without increasing the start-stop cost.

[0157] The upper array of hybrid electrolyzers adopts the principle of starting first and shutting down first, and starting last and shutting down last, so that the working time of each electrolyzer is kept as balanced as possible. Taking the ALK electrolyzer as an example, at t = 0, according to different operating conditions, N ALK The electrolytic cells are sorted, and the corresponding numbers are defined as queue Ω ALK ={1,2,3,···,N ALK -1,N ALK Without loss of generality, assume that the hydrogen production system determines that k ALK electrolyzers should be in a non-shutdown state (k<N ALK ), whose numbers form a first-in-first-out queue Right now The rest N ALK -k ALK electrolyzers are in shutdown state, and their numbers form another first-in-first-out queue Right now Assuming Δt is the electrolytic cell adjustment time step, the electrolytic cell array rotation process under different conditions is expressed as follows:

[0158] 1) If the wind and solar power output increases during the period t+Δt, the hydrogen production system decides that k+r ALK electrolyzers should be started during the period t+Δt, then The first r elements in are dequeued and added to the queue Tail, i.e. priority start queue The first r electrolytic cells in . It is expressed as:

[0159]

[0160] in, for A queue consisting of the first r elements of .

[0161] 2) If the wind and solar power output decreases during the period t+Δt, the hydrogen production system decides that kr ALK electrolyzers should be started during the period t+Δt, then The first r elements in are dequeued and added to the queue Tail, that is, close the queue first The first r electrolytic cells in . It is expressed as:

[0162]

[0163] in, for A queue consisting of the first r elements of .

[0164] The upper array of ALK electrolyzers rotates on and off in operation mode. Figure 8 and Fig. 9 As shown (assuming that the number of ALK electrolyzers is 10 and the number of newly started and shut down units is 3).

[0165] The rotation operation mode of the electrolyzer array under different conditions of the PEM electrolyzer is similar to that of the ALK electrolyzer and will not be described in detail.

[0166] On this basis, considering that a single electrolyzer cannot be overloaded and bear fluctuating power for too long, the lower layer adopts the conventional electrolyzer array rotation operation mode, and the electrolyzers in operation are rotated in order of number. Set the ALK electrolyzer rotation period to τ ALK , the PEM electrolyzer rotation period is τ PEM Taking the PEM electrolyzer as an example, the specific lower array rotation operation mode is as follows: Fig.10 As shown; each stage has three operating conditions, each operating condition is τ PEM The rotation operation is performed for the rotation period. PEM , the PEM electrolyzer will bear the operating power of the previous PEM electrolyzer in the order of numbers, and the fluctuating power will also be transferred from the current PEM electrolyzer to the next numbered PEM electrolyzer. When the wind and solar power output fluctuates greatly, the three operating conditions will change, and the PEM electrolyzer that bears the fluctuating power will be transferred from the current PEM electrolyzer to the next numbered PEM electrolyzer without renumbering and sorting. This array rotation strategy ensures that each electrolyzer is evenly divided in the time it bears the fluctuating conditions, and that the operating time of the electrolyzer monomer under different conditions is roughly the same, avoiding excessive use of some electrolyzers, which is beneficial to improving the service life of the overall system.

[0167] This embodiment takes maximizing the net profit of hydrogen production by the hybrid electrolyzer hydrogen production system as the evaluation target, and the decision variables are the number of ALK-PEM electrolyzers operating at each power point.

[0168] The objective function is:

[0169]

[0170] in, The revenue from selling hydrogen for the hybrid electrolyzer hydrogen production system; C op is the operating cost of the two electrolyzers; C curt Penalty costs for curtailing wind and solar power.

[0171]

[0172] in, is the unit price of hydrogen, which is 35 yuan / kg in this embodiment; is the hydrogen production of the ALK electrolyzer during period t; is the hydrogen production of the PEM electrolyzer during period t.

[0173]

[0174] in, is the energy consumed to produce unit hydrogen, in this example, 50 kW·h·kg -1 ; η ALK,h and η ALK,e are the hydrogen production efficiency of ALK electrolyzer operating at the highest efficiency point power and rated power, η ALK,f The hydrogen production efficiency corresponding to the fluctuating power borne by the ALK electrolyzer.

[0175]

[0176] Among them, η PEM,h , η PEM,e and η PEM,emax are the hydrogen production efficiencies of the PEM electrolyzer when operating at the highest efficiency point power, rated power, and overload power, respectively, and η PEM,f The hydrogen production efficiency corresponding to the fluctuating power borne by the PEM electrolyzer.

[0177] C op =C ALK,op +C PEM,op (42)

[0178]

[0179] Among them, C ALK,op and C PEM,op are the operating costs of ALK and PEM electrolyzers respectively; c ALK,op and c PEM,op are the operating cost coefficients of ALK and PEM electrolyzers, respectively.

[0180]

[0181] Among them, c curt is the unit penalty cost for abandoning wind and solar power, which is 0.6 yuan / (kW·h) in this embodiment; is the abandoned wind and solar power of the hydrogen production system during period t.

[0182] Constraints

[0183] 1) Power balance constraints

[0184]

[0185] 2) ALK-PEM electrolyzer output constraints

[0186]

[0187] 3) ALK electrolyzer power fluctuation constraints

[0188]

[0189] 4) PEM electrolyzer power fluctuation constraints

[0190]

[0191] 5) Minimum start and stop time constraints for ALK-PEM electrolyzers

[0192] See formula (9) to formula (16) for details.

[0193] 6) ALK-PEM electrolyzer array operation constraints

[0194] See formula (23) and formula (29) for details.

[0195] 7) ALK-PEM electrolyzer upper array rotation start and stop constraints

[0196] See formula (30)-formula (37) for details.

[0197] The mathematical model proposed in this embodiment is a mixed-integer linear program (MILP) problem, which can be directly solved using the commercial solver Gurobi.

[0198] Case Analysis

[0199] In order to verify the effectiveness of the optimal power allocation strategy for ALK-PEM combined hydrogen production proposed in this embodiment, this embodiment takes the demonstration project data of a certain region as an example, and configures the wind turbine capacity to be 120MW and the photovoltaic unit capacity to be 60MW. The relevant parameters of equipment such as ALK electrolyzers and PEM electrolyzers are specifically shown in Table 3. Considering the optimal configuration scheme of the ALK-PEM hybrid electrolyzer and the startup and regulation characteristics of the ALK and PEM electrolyzers, the capacity ratio of ALK to PEM is selected as 2.5:1, that is, the number of ALK electrolyzer arrays is configured to be N ALK (N ALK = 10) units, the number of PEM electrolyzer arrays is N PEM (N PEM =20). Considering the different time scales of the power response of the ALK-PEM electrolyzer, the scheduling period of this embodiment is 2h and the sampling time scale is in seconds. The model is solved by calling the Gurobi solver using MATLAB 2023b software. The computer configuration is Windows 11, the CPU model is Intel Core i7-14650H, the main frequency is 2.2GHz, and the memory is 16GB.

[0200] Table 3 Comparison of different electrolytic cell parameters

[0201]

[0202]

[0203] This embodiment performs a second-level forecast of wind and solar power unit output on six typical days randomly selected from the 8:00-10:00 period throughout the year. The wind and solar power output forecast results are as follows: Fig.11 shown.

[0204] In order to verify the effectiveness of the optimal power allocation strategy of the ALK-PEM combined hydrogen production system proposed in this embodiment, it is compared and analyzed with the traditional power allocation strategy. The comparison results of hydrogen production on 6 typical days are shown in Table 4.

[0205] Table 4 Operation status under different power allocation schemes on typical days

[0206]

[0207] As can be seen from Table 4, in the scheduling cycle of 6 typical days, in terms of hydrogen production, the total hydrogen production of the power allocation strategy in the traditional scheme is 8336.02 kg, and the total hydrogen production of the optimal power allocation strategy of the second-level ALK-PEM hydrogen production system taking into account the start and stop of the electrolyzer proposed in this embodiment can reach 8820.01 kg, and the total hydrogen production has increased by 5.806%. In terms of wind and solar power abandonment, the average wind and solar power abandonment rate in the traditional scheme is 7.08%, while the average wind and solar power abandonment rate of the power allocation strategy proposed in this embodiment is 0.785%, which is a decrease of 88.91%, significantly improving the system's ability to absorb wind and solar power. In terms of hydrogen production revenue, the hydrogen production revenue in the traditional scheme is 1.4965826 million yuan, while the total hydrogen production revenue under the scheme proposed in this embodiment can reach 2.0070732 million yuan, an increase of 34.110%. In summary, compared with the equal power distribution strategy in the traditional scheme, the optimal power allocation strategy of the ALK-PEM combined hydrogen production system in this embodiment can reasonably distribute the fluctuating power of wind and solar power according to the operating conditions of each electrolyzer array, maximize the utilization of the hydrogen production efficiency of the electrolyzer array, and effectively improve the wind and solar power absorption capacity while increasing the hydrogen production revenue.

[0208] In order to further verify the economic advantages of the optimal power allocation strategy of the ALK-PEM combined hydrogen production system proposed in this embodiment which takes into account the second-level start and stop characteristics of the electrolyzer, it is compared and analyzed with the power allocation strategy in the traditional scheme, and various hydrogen production costs of typical day 2 and typical day 4 are selected for comparison. The results are shown in Table 5.

[0209] Table 5 Hydrogen production cost under different power allocation schemes

[0210]

[0211] It can be seen from Table 5 that, compared with the traditional scheme, the penalty costs for wind and solar power abandonment in the scheme proposed in this embodiment are reduced by 89.57% and 94.63% respectively, the total operating costs of the electrolyzer are reduced by 5.46% and 17.94% respectively, and the start-up and shutdown costs in typical day 4 are reduced by 21.21%. This is because the proposed power allocation strategy comprehensively considers the operating characteristics of the ALK and PEM electrolyzers, allocates power according to the optimal efficiency operating mode of the ALK and PEM electrolyzers, can give full play to the complementary advantages of the ALK-PEM electrolyzers, reduce the start-up and shutdown operations of the electrolyzers, and help to improve the service life of the electrolyzers. Compared with the traditional scheme, although the operating cost of the ALK electrolyzer of the proposed scheme is higher than that of the traditional scheme, the corresponding operating cost of the PEM electrolyzer is greatly reduced. This is because the unit operating cost of the PEM electrolyzer is high. The scheme proposed in this embodiment reasonably allocates the wind and solar power output to avoid the excessive use of one electrolyzer, which not only effectively reduces the operating cost of the electrolyzer, but also increases the dispatchable space of the electrolyzer, verifying the effectiveness of the proposed scheme in terms of flexibility and economy.

[0212] In order to further verify the advantages of the power allocation strategy proposed in this embodiment that takes into account the second-level start-stop characteristics of the electrolyzer in absorbing the fluctuating power of wind and solar power, it is compared and analyzed with the power allocation strategy in the traditional scheme. The wind and solar power output and the electrolytic hydrogen production power comparison results on typical day 2 and typical day 4 are as follows: Fig.12 shown.

[0213] Depend on Fig.12 (a) and Fig.12 (b) By comparison, it can be seen that in the sampling time period 1 to 200 on typical day 2, the hydrogen production power of both schemes cannot effectively follow the fluctuation of wind and solar power, resulting in the abandonment of wind and solar power. This is because the wind and solar input power in this time period exceeds the maximum output power of ALK and PEM electrolyzers. At this time, ALK and PEM electrolyzers are both operating at maximum power; between sampling time periods 241 to 1440, compared with the traditional scheme, the hydrogen production power of ALK and PEM electrolyzers under the power allocation strategy proposed in this embodiment can effectively follow the fluctuating output of wind and solar power, and there is no abandonment of wind and solar power. This is because compared with the capacity-sharing power allocation strategy proposed in the traditional scheme, the scheme proposed in this embodiment allocates input power according to the optimal efficiency operation mode of ALK and PEM electrolyzers, so that the PEM electrolyzer retains a part of the hydrogen production capacity and has greater flexibility, thereby greatly improving the hydrogen production system's ability to absorb new energy. Fig.12 (c) and Fig.12(d) By comparison, it can be seen that in the sampling time period 181-420 on typical day 4, compared with the scheme proposed in the traditional scheme, the hydrogen production power of ALK and PEM electrolyzers under the power allocation strategy proposed in this embodiment can effectively follow the low-power wind and solar fluctuations, and there is no wind and solar abandonment. This is because the proposed scheme takes into account the situation where the average power in the lower-level power allocation strategy is less than the minimum value of the electrolyzer hydrogen production power, and formulates a targeted power allocation strategy according to the different situations of the hydrogen production power zoning, so that the hydrogen production system can better adapt to the different output levels of new energy.

[0214] In order to verify the hydrogen production power fast tracking capability of the PEM electrolyzer with second-level response characteristics proposed in this embodiment, the sampling time periods 481-800 of typical day 1 and typical day 6 were selected to compare the hydrogen production power on a second-level time scale with the conventional 5-minute-level time scale. The results are as follows: Fig.13 shown.

[0215] Depend on Fig.13 (a) It can be seen that in the sampling time period 481-780 in a typical day 1, when the wind and solar power output shows a weakening trend over time, compared with the conventional 5-minute time scale, the electrolyzer second-level time scale scheme proposed in this embodiment can configure the power required by each electrolyzer according to the wind and solar power in real time, and can quickly respond to wind and solar fluctuations, avoiding the unrealistic phenomenon that the hydrogen production power is higher than the wind and solar power output under the conventional 5-minute time scale; Fig.13 (b) It can be seen that in the sampling time period 541-780 in the typical day 1, when the wind and solar power output shows an increasing trend over time, compared with the conventional 5-minute time scale, the second-level time scale scheme of the electrolyzer proposed in this embodiment can quickly follow the wind and solar power output to adjust the hydrogen production power of the electrolyzer, avoiding the phenomenon that the hydrogen production power cannot quickly follow the wind and solar power output under the conventional 5-minute time scale, resulting in power abandonment. The proposed second-level time scale scheme can make full use of the wind and solar power output and improve the level of new energy consumption. In summary, the power optimal allocation strategy of the ALK-PEM electrolyzer hydrogen production system taking into account the second-level start-stop characteristics proposed in this embodiment can give full play to the second-level response characteristics of the PEM electrolyzer, realize rapid tracking of wind and solar power fluctuations, reduce the occurrence of wind and solar power abandonment, and significantly improve the ability to absorb new energy.

[0216] In order to verify the effectiveness of the ALK-PEM electrolyzer array cooperating with each other to produce hydrogen under the power allocation strategy proposed in this embodiment, taking the sampling period of 401-800 in June of a typical day as an example, the wind and solar power output curves and the hydrogen production states of the ALK and PEM electrolyzers are shown in the figure below: Fig.14 shown.

[0217] Depend on Fig.14(a) It can be seen that under the second-level power allocation strategy proposed in this embodiment, the power of hydrogen production by electrolysis can quickly follow the output of wind and solar power, reducing energy waste; Fig.14 (b)~ Fig.14 (e) It can be seen that in a single time period, there are multiple electrolyzers operating under different hydrogen production conditions, including operation at the highest efficiency point, rated operation, overload operation, and operation with fluctuating power. The second-level optimal power allocation strategy proposed in this embodiment is used to comprehensively consider key factors such as the power-efficiency curve, regulation performance, and capacity size of the ALK electrolyzer and the PEM electrolyzer, and formulate a corresponding power allocation plan to give priority to power allocation for ALK electrolyzers with lower operating costs, slower response speeds, larger capacity configurations, and poorer regulation performance. At the same time, as many electrolyzers as possible are ensured to operate simultaneously to give full play to their efficiency characteristics and reduce start-stop operations. Because of its second-level response characteristics, the PEM electrolyzer can cooperate with the ALK electrolyzer to absorb the remaining wind and solar power fluctuations. By reasonably allocating wind and solar power input power to reduce the occurrence of wind and solar power abandonment, the rational use of power is achieved. In addition, under the optimal power allocation strategy of the ALK-PEM combined hydrogen production system proposed in this embodiment that takes into account the second-level start and stop characteristics of the electrolyzer, the system does not have frequent start and stop operations. It mainly responds to the rapidly changing new energy output by adjusting the power of the electrolyzer in operation. The proposed power allocation strategy can not only maximize the absorption of new energy power, but also avoid frequent start and stop of hydrogen production equipment, verifying the effectiveness of the proposed optimal power allocation strategy.

[0218] In order to verify the effectiveness of the ALK-PEM electrolyzer double-layer array rotation operation mode under the power allocation strategy proposed in this embodiment, the first 6 ALK electrolyzers in the typical day 4 sampling time period 1 to 10 are taken as an example (the remaining 4 electrolyzers have been in the hydrogen production operation state in the sampling time period 1 to 10, which is similar to the operation state of ALK electrolyzer 6 and will not be repeated). The upper array rotation operation state diagram is as follows Fig.15 shown.

[0219] Depend on Fig.15It can be seen that at the initial moment of sampling, ALK electrolyzer 1 is in shutdown state, and the other five electrolyzers are in hydrogen production operation state; when the hydrogen production system decides that a total of two ALK electrolyzers need to be shut down in sampling period 2, ALK electrolyzer 2 is shut down on the basis that ALK electrolyzer 1 has been shut down, that is, ALK electrolyzer 2, which is running first, is shut down first, and the remaining electrolyzers remain in operation; similarly, electrolyzers 3 and 4 are shut down in sampling period 4, and electrolyzer 5 is shut down in sampling period 5. When the hydrogen production system decides that a total of 9 ALK electrolyzers need to be started during sampling period 7, based on the fact that ALK electrolyzers 6 to 10 have been started during sampling period 7, a start-up signal needs to be applied to ALK electrolyzers 1 to 4 that were shut down first during sampling period 6 to put them into a hot start state, and enter the hydrogen production operation stage after the ALK electrolyzer minimum start-up time of 5 minutes (sampling period 7); similarly, a start-up signal is applied to electrolyzer 5 during sampling period 7 to put it into the hydrogen production operation stage during sampling period 8, satisfying the start-stop strategy of shutting down first and starting up later, and shutting down later and starting up later. In summary, the upper array rotation operation mode adopted in this embodiment can balance the working time of each electrolyzer as much as possible, extend the service life of the electrolyzer array without increasing the start-stop cost, and verify the feasibility of the upper array rotation operation mode of the electrolyzer under the proposed power allocation strategy.

[0220] In order to further verify the effectiveness of the rotation operation mode of the lower array of hybrid electrolyzers, the first six PEM electrolyzers in the 306-385 period of typical day 5 sampling were selected, and the rotation operation status of the lower array is shown in the figure below. Fig.16 shown.

[0221] Depend on Fig.16 It can be seen that during the sampling period, 14 PEM electrolyzers are operating at rated power, 5 PEM electrolyzers are operating at the highest efficiency point, and the remaining 1 PEM electrolyzer is operating in a fluctuating state. At the same time, the rotation period τ of the PEM electrolyzer is set PEM =10s, that is, every 10s, the operating state of the PEM electrolyzer will rotate once in a sequential array form. For example, at sampling time 306, PEM electrolyzer 1 bears the fluctuating power, and at sampling time 307, the fluctuating power is borne by PEM electrolyzer 2, and so on. In summary, the lower array rotation operation mode adopted in this embodiment can achieve the most balanced time share of each electrolyzer monomer under different operating conditions, avoid excessive use of some electrolyzers, ensure the safe and stable operation of each electrolyzer, reduce the safety risks in the operation process of the electrolyzer, improve the safety and reliability of hydrogen production, and help to improve the overall service life of the ALK-PEM electrolyzer combined hydrogen production system.

[0222] Using green electricity to produce hydrogen by electrolysis is one of the main ways to absorb new energy and clean energy. In order to enhance the adaptability between the hydrogen production system and the fluctuating electrolysis power supply and improve the hydrogen production income, this embodiment proposes an ALK-PEM electrolyzer combined electrolysis hydrogen production method. At the same time, based on the second-level response characteristics of the PEM electrolyzer and the large single-cell capacity and good economy of the ALK electrolyzer, the optimal power allocation of the hydrogen production system is studied in combination with typical scenarios. Through example analysis, the following conclusions are drawn:

[0223] 1) The proposed second-level start-stop method, by further shortening the time scale, gives full play to the second-level response characteristics of the PEM electrolyzer, fully utilizes the wind and solar power output, reduces the occurrence of wind and solar power abandonment, and effectively improves the level of new energy consumption;

[0224] 2) The proposed ALK-PEM electrolyzer combined hydrogen production system power optimal allocation strategy can improve the adaptability of the hydrogen production system to the input wind and solar power fluctuations. Compared with the equal distribution strategy, the proposed highest efficiency operation mode allocation strategy increased the total hydrogen production by 5.806%, reduced the system wind and solar power abandonment rate by 88.91%, and increased the system hydrogen production revenue by 34.110%, significantly improving the economy and flexibility of the ALK-PEM electrolyzer combined hydrogen production system and realizing the rational utilization of the hybrid electrolyzer capacity.

[0225] 3) The optimal power allocation strategy proposed allocates power according to the highest efficiency operation mode of the ALK-PEM electrolyzer, fully taps the hydrogen production potential of the two electrolyzers, achieves complementary advantages, and avoids frequent start and stop while ensuring the maximum hydrogen production benefits, thereby improving the level of new energy consumption;

[0226] 4) In order to balance the operating time of each electrolyzer under different working conditions, this embodiment constructs a double-layer array rotation operation model for hybrid electrolyzers. The results show that the use of a double-layer array rotation operation strategy can effectively avoid excessive use of some electrolyzers. Without increasing the start-up and shutdown costs of the electrolyzers, it ensures the state consistency of each electrolyzer and the operational safety of the hydrogen production system, which is beneficial to improving the overall service life of the hydrogen production system.

[0227] In view of the fact that the existing electrolyzer models mostly describe their operating characteristics at the time scale of hours or minutes, and fail to fully exploit their second-level start-stop characteristics, resulting in low operating efficiency and insufficient new energy consumption capacity, this embodiment proposes an optimal power allocation strategy for the ALK electrolyte and PEM electrolyzer combined hydrogen production system taking into account the second-level start-stop characteristics of the electrolyzer; analyzes the operating mechanisms of ALK and PEM electrolyzers, and deduces their power-efficiency curves; formulates an optimal power allocation strategy for the ALK-PEM combined electrolysis hydrogen production system based on the highest efficiency point, rated power point and overload power point on the curve, and considers the operating costs, single cell capacity, regulation performance of the two electrolyzers, and the second-level start-stop and second-level response of the PEM electrolyzer; on this basis, combined with the rotation operation rules of the multi-electrolyzer double-layer array, a reasonable allocation of array power between groups of the hybrid electrolyzer hydrogen production system is achieved; finally, taking the actual data of a demonstration project in a certain region as an example, it is verified that the proposed ALK-PEM electrolyzer optimal power allocation strategy can promote the consumption of new energy while increasing the hydrogen production revenue.

[0228] Embodiment 2

[0229] The second embodiment of the present invention introduces a power distribution system for an ALK-PEM electrolyzer hydrogen production system.

[0230] like Fig.17 The power distribution system of an ALK-PEM electrolyzer hydrogen production system shown includes:

[0231] An acquisition module configured to acquire operating characteristics of the ALK electrolyzer and the PEM electrolyzer and construct an ALK-PEM electrolyzer combined hydrogen production system;

[0232] A determination module, which is configured to determine the operation mode of the electrolyzer of the hydrogen production system by adopting a double-layer rotation operation mode of the electrolyzer array based on the start-stop characteristics of the electrolyzer of the constructed ALK-PEM electrolyzer combined hydrogen production system, taking into account the second-level start-stop characteristics of the PEM electrolyzer;

[0233] A construction module is configured to construct an optimal power allocation model taking into account the start and stop of the electrolyzer according to the determined electrolyzer operation mode and with the goal of maximizing the net profit of the hybrid electrolyzer hydrogen production system;

[0234] A solution module is configured to solve the constructed optimal power allocation model to complete the power allocation of the ALK-PEM electrolyzer hydrogen production system.

[0235] The detailed steps are the same as those of the power allocation method for an ALK-PEM electrolyzer hydrogen production system provided in Example 1, and will not be repeated here.

[0236] Embodiment 3

[0237] Embodiment 3 of the present invention provides a computer-readable storage medium.

[0238] A computer-readable storage medium stores a program thereon, which, when executed by a processor, implements the steps in a power allocation method for an ALK-PEM electrolyzer hydrogen production system as described in Embodiment 1 of the present invention.

[0239] The detailed steps are the same as those of the power allocation method for an ALK-PEM electrolyzer hydrogen production system provided in Example 1, and will not be repeated here.

[0240] Embodiment 4

[0241] A fourth embodiment of the present invention provides an electronic device.

[0242] An electronic device comprises a memory, a processor and a program stored in the memory and running on the processor, wherein when the processor executes the program, the steps in a power distribution method for an ALK-PEM electrolyzer hydrogen production system as described in Embodiment 1 of the present invention are implemented.

[0243] The detailed steps are the same as those of the power allocation method for an ALK-PEM electrolyzer hydrogen production system provided in Example 1, and will not be repeated here.

[0244] Embodiment 5

[0245] Embodiment 5 of the present invention provides a computer program product.

[0246] A computer program product includes software code, wherein the program in the software code executes the steps in the power allocation method of an ALK-PEM electrolyzer hydrogen production system as described in the first embodiment of the present invention.

[0247] The detailed steps are the same as those of the power allocation method for an ALK-PEM electrolyzer hydrogen production system provided in Example 1, and will not be repeated here.

[0248] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0249] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0250] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0251] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0252] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0253] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0254] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A power allocation method for an ALK-PEM electrolyzer hydrogen production system, characterized in that: include: Obtain the operating characteristics of ALK electrolyzer and PEM electrolyzer, and build an ALK-PEM electrolyzer combined hydrogen production system; Based on the start-stop characteristics of the electrolyzer of the constructed ALK-PEM electrolyzer combined hydrogen production system, the operation mode of the electrolyzer of the hydrogen production system is determined by adopting the double-layer rotation operation mode of the electrolyzer array, taking into account the second-level start-stop characteristics of the PEM electrolyzer. According to the determined electrolyzer operation mode, the optimal power allocation model taking into account the start and stop of the electrolyzer is constructed with the goal of maximizing the net profit of the hybrid electrolyzer hydrogen production system; Solve the constructed optimal power allocation model and complete the power allocation of the ALK-PEM electrolyzer hydrogen production system.

2. A power allocation method for an ALK-PEM electrolyzer hydrogen production system as claimed in claim 1, characterized in that: The double-layer rotation operation mode of the electrolytic cell array adopted is that the upper layer adopts the principle of start-first-shutdown and start-last-shutdown to balance the working time of different electrolytic cells, and the lower layer performs array rotation operation according to the operating conditions of the electrolytic cell single hydrogen production.

3. A power distribution method for an ALK-PEM electrolyzer hydrogen production system as claimed in claim 2, characterized in that: The operating conditions of the electrolyzer unit for hydrogen production at least include a shutdown operating state, a high-efficiency operating state, a rated operating state, an overload operating state and a fluctuating operating state.

4. A power distribution method for an ALK-PEM electrolyzer hydrogen production system as claimed in claim 1, characterized in that: The objective function of the optimal power allocation model considering the start and stop of the electrolyzer is: Where F is the net income of the hybrid electrolyzer hydrogen production system; The revenue from selling hydrogen for the hybrid electrolyzer hydrogen production system; C op is the operating cost of ALK electrolyzer and PEM electrolyzer; C on is the operating cost of the hybrid electrolyzer hydrogen production system; C off is the shutdown cost of the hybrid electrolyzer hydrogen production system; C curt Penalty costs for wind and solar curtailment in hybrid electrolyzer hydrogen production systems.

5. A power distribution method for an ALK-PEM electrolyzer hydrogen production system as claimed in claim 1, characterized in that: The constraints of the constructed optimal power allocation model taking into account the start and stop of the electrolyzer include at least power balance constraints, ALK-PEM electrolyzer output constraints, ALK electrolyzer fluctuating power constraints, PEM electrolyzer fluctuating power constraints, ALK-PEM electrolyzer minimum start and stop time constraints, ALK-PEM electrolyzer array operation constraints and ALK-PEM electrolyzer upper array rotation start and stop constraints.

6. A power distribution method for an ALK-PEM electrolyzer hydrogen production system as claimed in claim 1, characterized in that: The obtained operating characteristics of the ALK electrolyzer and the PEM electrolyzer include at least the power-efficiency curve, electrolyzer single cell capacity, electrolyzer regulation performance, operating cost, start-stop characteristics and second-level response characteristics.

7. A power distribution system for an ALK-PEM electrolyzer hydrogen production system, characterized in that: include: An acquisition module configured to acquire operating characteristics of the ALK electrolyzer and the PEM electrolyzer and construct an ALK-PEM electrolyzer combined hydrogen production system; A determination module, which is configured to determine the operation mode of the electrolyzer of the hydrogen production system by adopting a double-layer rotation operation mode of the electrolyzer array based on the start-stop characteristics of the electrolyzer of the constructed ALK-PEM electrolyzer combined hydrogen production system, taking into account the second-level start-stop characteristics of the PEM electrolyzer; A construction module is configured to construct an optimal power allocation model taking into account the start and stop of the electrolyzer according to the determined electrolyzer operation mode and with the goal of maximizing the net profit of the hybrid electrolyzer hydrogen production system; A solution module is configured to solve the constructed optimal power allocation model to complete the power allocation of the ALK-PEM electrolyzer hydrogen production system.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of a power allocation method for an ALK-PEM electrolyzer hydrogen production system as described in any one of claims 1-6 are implemented.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the program, the steps of a power allocation method for an ALK-PEM electrolyzer hydrogen production system as described in any one of claims 1-6 are implemented.

10. A computer program product comprising software code, characterized in that The program in the software code executes the steps of a power allocation method for an ALK-PEM electrolyzer hydrogen production system as described in any one of claims 1-6.

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