Optimal planning method and system for grid-connected green hydrogen plant considering electrolyzer parameters and safety constraints

Abstract

The application discloses a grid-connected green hydrogen plant optimization planning method and system considering electrolytic cell parameters and safety constraints, and the method comprises the following steps: constructing an optimization planning model according to operation parameters of the grid-connected green hydrogen plant; constructing a PEM electrolytic cell steady-state model, taking internal parameters of the PEM electrolytic cell as decision variables of the optimization planning model; taking minimum hydrogen gas leveling cost as a target function, establishing a constraint condition, solving the optimization planning model, and obtaining optimal configuration results meeting safety operation requirements. The application aims to meet grid access conditions, hydrogen gas demand and safety operation requirements, unify capacity configuration of the internal parameters of the PEM electrolytic cell, the electrolytic cell, the power converter, the compressor, the hydrogen storage device and the optional battery energy storage system into an optimization planning framework, realize collaborative optimization of equipment configuration and operation scheme of the grid-connected green hydrogen plant, reduce hydrogen gas leveling cost, and improve engineering implementability of system design.

Description

Technical Field

[0001] This invention belongs to the technical field of electro-hydrogen coupling system optimization planning and green hydrogen plant design, specifically involving a grid-connected green hydrogen plant optimization planning method and system that considers electrolyzer parameters and safety constraints. Background Technology

[0002] Hydrogen energy, as an important secondary energy source for achieving a green and low-carbon energy transition, boasts advantages such as clean utilization and energy storage across time scales. Producing green hydrogen through water electrolysis using renewable energy sources such as wind and solar power is a crucial technological pathway for achieving low-carbon hydrogen energy. With the continuous increase in installed capacity of renewable energy, the planning and operation of green hydrogen plants for grid-connected scenarios are receiving increasing attention.

[0003] Green hydrogen plants typically consist of electrolysis units, compressors, hydrogen storage units, power converters, and optional energy storage systems. The system structure is complex, and equipment investment is high. Furthermore, their operational performance is affected by a variety of factors, including electricity price fluctuations, changes in renewable energy output, grid connection capacity, and hydrogen demand. Therefore, achieving reasonable equipment configuration, safe and reliable operation, and controllable hydrogen production costs for green hydrogen plants while meeting grid connection requirements and hydrogen demand has become a pressing technical challenge.

[0004] Current research on green hydrogen systems mainly focuses on two aspects: operation optimization and capacity configuration. However, most methods simplify the electrolyzer as a fixed-efficiency device, failing to fully reflect the characteristics of electrolysis efficiency changing with operating conditions, and rarely incorporating the internal parameters of the electrolyzer into a unified system-level optimization framework. For proton exchange membrane electrolyzers (PEM electrolyzers), internal parameters such as membrane thickness, cathode pressure, and cell area significantly affect electrolysis efficiency, cross-permeability levels, and safe operating range. Existing technologies do not adequately consider the synergistic relationship between these internal parameters and system equipment capacity configuration.

[0005] Furthermore, PEM electrolyzers operating at low current densities may experience increased hydrogen content in oxygen due to enhanced hydrogen cross-permeability, posing a safety risk. Failure to incorporate such safety boundaries into the system planning phase may result in designs that, while economically viable, lack engineering feasibility. On the other hand, while battery energy storage systems can mitigate input power fluctuations under conditions of fluctuating renewable energy supply, current methods do not adequately consider how the integration of such systems affects the selection of internal parameters of the PEM electrolyzer and the overall system configuration.

[0006] Therefore, in view of the common problems in the existing green hydrogen plant optimization design methods, such as simplified modeling of electrolyzers, disconnect between internal parameters and system-level configuration, insufficient consideration of safety operation boundaries, and inadequate analysis of energy storage synergy, it is necessary to propose a green hydrogen plant optimization planning method that can comprehensively consider the internal parameters of PEM electrolyzers, safety operation constraints, energy storage synergy, and grid connection conditions, so as to improve the rationality, economy, and engineering feasibility of green hydrogen plant design. Summary of the Invention

[0007] The purpose of this invention is to provide an optimization planning method and system for grid-connected green hydrogen plants that considers electrolyzer parameters and safety constraints. Based on meeting grid connection conditions, hydrogen demand, and safe operation requirements, this method integrates the internal parameters of the PEM electrolyzer with the capacity configuration of the electrolyzer, power converter, compressor, hydrogen storage device, and optional battery energy storage system into an optimization planning framework. This achieves coordinated optimization of equipment configuration and operation schemes for grid-connected green hydrogen plants, reduces the levelized cost of hydrogen, and improves the engineering feasibility of the system design.

[0008] To achieve the above objectives, the solution of the present invention is:

[0009] An optimization planning method for grid-connected green hydrogen plants considering electrolyzer parameters and safety constraints includes,

[0010] Based on the operating parameters of the grid-connected green hydrogen plant, an optimization planning model is constructed;

[0011] A steady-state model of a PEM electrolyzer is constructed, with the internal parameters of the PEM electrolyzer used as decision variables for the optimization planning model; wherein, the internal parameters of the electrolyzer include film thickness, cathode pressure, and cell area;

[0012] Using the minimum levelized cost of hydrogen as the objective function, constraints including electrolyzer operation constraints, safety constraints, hydrogen production and storage constraints, battery energy storage system operation constraints, and grid connection constraints are established. The optimization planning model is then solved to obtain the optimal configuration result that meets the requirements of safe operation.

[0013] The operating parameters of the grid-connected green hydrogen plant include hydrogen demand data, electricity price scenario data, renewable energy output data, available power boundary data for grid connection, equipment cost parameters, and electrolyzer safety threshold parameters. Hydrogen demand data is defined as an hourly hydrogen demand sequence within the study period. Electricity price scenario data is constructed from historical electricity price data. Renewable energy output data includes time-series scenario data of solar irradiance and wind speed. Available power boundary data for grid connection is constructed using the maximum available power at the connection point. Equipment cost parameters include at least the unit investment cost of the PEM electrolyzer, the unit investment cost of the battery energy storage system, the unit investment cost of the power converter, the unit investment cost of the compressor, and the unit investment cost of the hydrogen storage device, as well as the corresponding operating cost parameters. Electrolyzer safety threshold parameters include the maximum allowable value of hydrogen content in oxygen, used to limit the hydrogen content in oxygen in the PEM electrolyzer under different operating conditions from exceeding a preset safety boundary, thus serving as a safety constraint input in the subsequent optimization planning model.

[0014] Specifically, a steady-state model of the PEM electrolyzer is constructed, using the internal parameters of the PEM electrolyzer as the decision variables of the optimization planning model, including:

[0015] Construct a steady-state model of the PEM electrolyzer, and determine the film thickness. Cathode pressure and battery area As an internal parameter to be optimized;

[0016] The PEM electrolyzer steady-state model is used to characterize the relationship between the internal parameters and the electrolyzer efficiency and safe operating boundaries; wherein, the hydrogen cross-permeation equivalent current density is expressed as...

[0017]

[0018] in, This represents the equivalent current density of hydrogen cross-permeation. Denotes Faraday's constant. This indicates hydrogen permeability in relation to temperature. Indicates the coefficient of membrane expansion. This represents the cross-penetration current density constant. Indicates the operating current density;

[0019] The hydrogen content in oxygen is expressed as...

[0020]

[0021] in, This represents the integral of hydrogen gas in oxygen.

[0022] The efficiency of a PEM electrolyzer is expressed as follows:

[0023]

[0024] in, Indicates the efficiency of the electrolytic cell. Indicates hydrogen production efficiency. Indicates Faraday efficiency;

[0025] The internal parameters are used as decision variables in the optimization planning model. They are jointly optimized with the rated power of the PEM electrolyzer, the rated power of the compressor, the capacity of the hydrogen storage device, and the configuration parameters of the battery energy storage system to determine the optimal configuration scheme for the grid-connected green hydrogen plant.

[0026] The objective function is to minimize the levelized cost of hydrogen, which is expressed as:

[0027]

[0028] in, This represents the levelized cost of hydrogen. Indicates capital expenditure, Indicates the first Operating expenses under different electricity pricing scenarios Indicates the first The probability of each electricity price scenario. Indicates the cost of equipment degradation. Indicates subsidy items, This indicates the total hydrogen demand during the research period;

[0029] Wherein, the system capital expenditure is expressed as,

[0030]

[0031] in, , , and These represent the rated capacities of the PEM electrolyzer, battery energy storage system, power converter, and compressor, respectively. Indicates the capacity of the hydrogen storage device. , , , and These represent the unit capacity investment cost of the corresponding equipment;

[0032] No. Operating expenses under individual electricity pricing scenarios Represented as,

[0033]

[0034] in, For time period sets, Indicates time period Total power purchased from the grid, Indicates the first Electricity pricing scenarios and time periods The electricity purchase price; Indicates time period Hydrogen production flow rate, Indicates time period Hydrogen storage flow rate, Indicates time period PEM electrolytic cell power, Indicates time period The compressor power; , , and These represent the unit cost of hydrogen production, the cost of hydrogen storage, the operating cost of the electrolyzer, and the operating cost of the compressor, respectively.

[0035] Equipment degradation costs Represented as,

[0036]

[0037] in, Indicates time period The power of the battery energy storage system, Indicates time period The unit degradation cost of battery energy storage systems This indicates the unit degradation cost of a PEM electrolyzer;

[0038] Subsidy The data is determined based on the unit hydrogen subsidy and the hydrogen demand during the research period, and is used to characterize the impact of the subsidy mechanism on the optimal configuration of grid-connected green hydrogen plants.

[0039] The electrolyzer operating constraints include power constraints, cell area constraints, and cathode pressure constraints, which are expressed as follows:

[0040]

[0041]

[0042]

[0043] in, Indicates time period PEM electrolytic cell power, Indicates the maximum allowable current density. This indicates the rated voltage of the PEM electrolytic cell. Indicates the battery area. Indicates cathode pressure; and These represent the lower and upper limits of the battery area, respectively. and These represent the lower and upper limits of the cathode pressure, respectively.

[0044] Safety constraints are represented as follows:

[0045]

[0046] in, Indicates time period The integral number of hydrogen gas in oxygen gas. This indicates the maximum permissible hydrogen content in oxygen.

[0047] Among them, hydrogen production and storage constraints include hydrogen production flow constraints, hydrogen storage state constraints, and hydrogen balance constraints.

[0048] Among them, the PEM electrolyzer is in the time period The hydrogen production flow rate is expressed as,

[0049]

[0050] in, Indicates time period Hydrogen production flow rate, Indicates time period PEM electrolytic cell power, Indicates time period The efficiency of PEM electrolyzers This indicates the lower heating value of hydrogen.

[0051] Hydrogen storage devices during time periods The hydrogen storage state is satisfied.

[0052]

[0053] in, Indicates time period hydrogen storage state, and These represent the lower and upper limits of hydrogen storage conditions, respectively;

[0054] The hydrogen storage state is expressed as follows:

[0055]

[0056] in, This represents the loss coefficient of the hydrogen storage device. and They represent time periods respectively. and time period Hydrogen storage flow rate, Indicates the capacity of the hydrogen storage device;

[0057] The grid-connected green hydrogen plant maintains a balance between hydrogen supply and demand at different times.

[0058]

[0059] in, Indicates time period The demand for hydrogen.

[0060] Among them, the operational constraints of the battery energy storage system include state of charge constraints, state of charge / discharge update constraints, and battery energy storage system configuration constraints;

[0061] Among them, battery energy storage systems during time periods The state of charge satisfies,

[0062]

[0063] in, Indicates time period The state of charge, and These represent the upper and lower limits of the charged state, respectively;

[0064] After considering the charging and discharging efficiency and self-loss of the battery energy storage system, the time period The state of charge is represented as,

[0065]

[0066] In the formula, This represents the self-loss coefficient of the battery energy storage system. This indicates the charge and discharge efficiency of the battery energy storage system. Indicates time period The power of the battery energy storage system, Indicates the rated capacity of the battery energy storage system; where, when When the battery is charging, it indicates that the battery energy storage system is in a charging state; when When this time, it indicates that the battery energy storage system is in a discharging state.

[0067] This includes establishing grid access constraints, including:

[0068] Assume the green hydrogen plant connected to the grid is connected to the busbar as follows: Then the time period The total power obtained by the grid-connected green hydrogen plant from the power grid is sufficient.

[0069]

[0070] in, Indicates time period The total power obtained by the grid-connected green hydrogen plant from the power grid, Indicates time period Downstream access bus Maximum available power at the location;

[0071] Among them, total power Represented as,

[0072]

[0073] in, , and They represent time periods respectively. The power of the PEM electrolyzer, the power of the compressor, and the power of the battery energy storage system;

[0074] Busbar Maximum available power at the location It is obtained by weighted averaging of the maximum available power at the access point under each renewable energy combination state, and is expressed as follows:

[0075]

[0076] in, Indicates time period Next combination state The probability, Represents the combination state Next period The maximum available power of the access point, This represents the number of discrete states for solar irradiance and wind speed within a given time period.

[0077] When a grid-connected green hydrogen plant is required to produce pure green hydrogen using only renewable energy, the maximum available power at the access point is further satisfied.

[0078]

[0079] in, and Representing the combination states respectively Time period Next The first photovoltaic power station and the first Available power of a wind farm and These represent the number of photovoltaic power plants and wind farms, respectively. Represents a sufficiently large positive number. This represents a Boolean variable; when pure green hydrogen production is required, ;otherwise, .

[0080] The optimization planning model is solved to obtain the optimal configuration result that meets the requirements for safe operation, including:

[0081] The optimal configuration result includes at least the optimal values ​​of the internal parameters of the PEM electrolyzer, the capacity configuration results of each device, and the corresponding economic evaluation results.

[0082] The optimal values ​​of the internal parameters of the PEM electrolyzer include the film thickness. Cathode pressure and battery area The optimal value;

[0083] The capacity configuration results for each piece of equipment include the rated power of the PEM electrolyzer. Rated power of power converter Compressor rated power Hydrogen storage device capacity and the rated power of the battery energy storage system and rated capacity ;

[0084] The economic evaluation results should include at least the levelized cost of hydrogen. It may further include the PEM electrolyzer power at each time point during the study period. Compressor power Battery energy storage system power Hydrogen production flow rate Hydrogen storage state and state of charge ;

[0085] The optimal configuration results are used to characterize the optimal equipment selection and operation configuration scheme of the grid-connected green hydrogen plant under given hydrogen demand, electricity price scenarios, renewable energy output, grid access boundary and safety threshold conditions.

[0086] An optimization planning system for grid-connected green hydrogen plants, considering electrolyzer parameters and safety constraints, includes:

[0087] The optimization planning model building module is configured to build an optimization planning model based on the operating parameters of the grid-connected green hydrogen plant;

[0088] The electrolyzer steady-state model construction module is configured to construct a PEM electrolyzer steady-state model, using the internal parameters of the PEM electrolyzer as decision variables for the optimization planning model; wherein, the internal parameters of the electrolyzer include film thickness, cathode pressure, and cell area; and,

[0089] The model solving module is configured to take the minimum hydrogen levelized cost as the objective function, establish constraints including electrolyzer operation constraints, safety constraints, hydrogen production and storage constraints, battery energy storage system operation constraints, and grid connection constraints, and solve the optimization planning model to obtain the optimal configuration result that meets the safety operation requirements.

[0090] The operating parameters of the grid-connected green hydrogen plant include hydrogen demand data, electricity price scenario data, renewable energy output data, available power boundary data for grid connection, equipment cost parameters, and electrolyzer safety threshold parameters. Specifically, hydrogen demand data is defined as an hourly hydrogen demand sequence within the study period; electricity price scenario data is constructed from historical electricity price data; renewable energy output data includes time-series scenario data of solar irradiance and wind speed; and available power boundary data for grid connection is constructed from the maximum available power at the connection point. Equipment cost parameters include at least the unit investment cost of the PEM electrolyzer, the unit investment cost of the battery energy storage system, the unit investment cost of the power converter, the unit investment cost of the compressor, and the unit investment cost of the hydrogen storage device, as well as the corresponding operating cost parameters. Electrolyzer safety threshold parameters include the maximum permissible value of hydrogen content in oxygen.

[0091] The electrolyzer steady-state model construction module constructs a PEM electrolyzer steady-state model, using the internal parameters of the PEM electrolyzer as decision variables for the optimization planning model, including:

[0092] Construct a steady-state model of the PEM electrolyzer, and determine the film thickness. Cathode pressure and battery area As an internal parameter to be optimized;

[0093] The PEM electrolyzer steady-state model is used to characterize the relationship between the internal parameters and the electrolyzer efficiency and safe operating boundaries; wherein, the hydrogen cross-permeation equivalent current density is expressed as...

[0094]

[0095] in, This represents the equivalent current density of hydrogen cross-permeation. Denotes Faraday's constant. This indicates hydrogen permeability in relation to temperature. Indicates the coefficient of membrane expansion. This represents the cross-penetration current density constant. Indicates the operating current density;

[0096] The hydrogen content in oxygen is expressed as...

[0097]

[0098] in, This represents the integral of hydrogen gas in oxygen.

[0099] The efficiency of a PEM electrolyzer is expressed as follows:

[0100]

[0101] in, Indicates the efficiency of the electrolytic cell. Indicates hydrogen production efficiency. Indicates Faraday efficiency;

[0102] The internal parameters are used as decision variables in the optimization planning model. They are jointly optimized with the rated power of the PEM electrolyzer, the rated power of the compressor, the capacity of the hydrogen storage device, and the configuration parameters of the battery energy storage system to determine the optimal configuration scheme for the grid-connected green hydrogen plant.

[0103] The model solution module uses the minimum hydrogen levelization cost as the objective function, which is expressed as:

[0104]

[0105] in, This represents the levelized cost of hydrogen. Indicates capital expenditure, Indicates the first Operating expenses under different electricity pricing scenarios Indicates the first The probability of each electricity price scenario. Indicates the cost of equipment degradation. Indicates subsidy items, This indicates the total hydrogen demand during the research period;

[0106] Wherein, the system capital expenditure is expressed as,

[0107]

[0108] in, , , and These represent the rated capacities of the PEM electrolyzer, battery energy storage system, power converter, and compressor, respectively. Indicates the capacity of the hydrogen storage device. , , , and These represent the unit capacity investment cost of the corresponding equipment;

[0109] No. Operating expenses under individual electricity pricing scenarios Represented as,

[0110]

[0111] in, For time period sets, Indicates time period Total power purchased from the grid, Indicates the first Electricity pricing scenarios and time periods The electricity purchase price; Indicates time period Hydrogen production flow rate, Indicates time period Hydrogen storage flow rate, Indicates time period PEM electrolytic cell power, Indicates time period The compressor power; , , and These represent the unit cost of hydrogen production, the cost of hydrogen storage, the operating cost of the electrolyzer, and the operating cost of the compressor, respectively.

[0112] Equipment degradation costs Represented as,

[0113]

[0114] in, Indicates time period The power of the battery energy storage system, Indicates time period The unit degradation cost of battery energy storage systems This indicates the unit degradation cost of a PEM electrolyzer;

[0115] Subsidy The amount is determined based on the unit's hydrogen subsidy and the hydrogen demand during the research period.

[0116] The electrolyzer operating constraints include power constraints, cell area constraints, and cathode pressure constraints, which are expressed as follows:

[0117]

[0118]

[0119]

[0120] in, Indicates time period PEM electrolytic cell power, Indicates the maximum allowable current density. This indicates the rated voltage of the PEM electrolytic cell. Indicates the battery area. Indicates cathode pressure; and These represent the lower and upper limits of the battery area, respectively. and These represent the lower and upper limits of the cathode pressure, respectively.

[0121] Safety constraints are represented as follows:

[0122]

[0123] in, Indicates time period The integral number of hydrogen gas in oxygen gas. This indicates the maximum permissible hydrogen content in oxygen.

[0124] Among them, hydrogen production and storage constraints include hydrogen production flow constraints, hydrogen storage state constraints, and hydrogen balance constraints.

[0125] Among them, the PEM electrolyzer is in the time period The hydrogen production flow rate is expressed as,

[0126]

[0127] in, Indicates time period Hydrogen production flow rate, Indicates time period PEM electrolytic cell power, Indicates time period The efficiency of PEM electrolyzers This indicates the lower heating value of hydrogen.

[0128] Hydrogen storage devices during time periods The hydrogen storage state is satisfied.

[0129]

[0130] in, Indicates time period hydrogen storage state, and These represent the lower and upper limits of hydrogen storage conditions, respectively;

[0131] The hydrogen storage state is expressed as follows:

[0132]

[0133] in, This represents the loss coefficient of the hydrogen storage device. and They represent time periods respectively. and time period Hydrogen storage flow rate, Indicates the capacity of the hydrogen storage device;

[0134] The grid-connected green hydrogen plant maintains a balance between hydrogen supply and demand at different times.

[0135]

[0136] in, Indicates time period The demand for hydrogen.

[0137] Among them, the operational constraints of the battery energy storage system include state of charge constraints, state of charge / discharge update constraints, and battery energy storage system configuration constraints;

[0138] Among them, battery energy storage systems during time periods The state of charge satisfies,

[0139]

[0140] in, Indicates time period The state of charge, and These represent the upper and lower limits of the charged state, respectively;

[0141] After considering the charging and discharging efficiency and self-loss of the battery energy storage system, the time period The state of charge is represented as,

[0142]

[0143] In the formula, This represents the self-loss coefficient of the battery energy storage system. This indicates the charge and discharge efficiency of the battery energy storage system. Indicates time period The power of the battery energy storage system, Indicates the rated capacity of the battery energy storage system; where, when When the battery is charging, it indicates that the battery energy storage system is in a charging state; when When this time, it indicates that the battery energy storage system is in a discharging state.

[0144] This includes establishing grid access constraints, including:

[0145] Assume the green hydrogen plant connected to the grid is connected to the busbar as follows: Then the time period The total power obtained by the grid-connected green hydrogen plant from the power grid is sufficient.

[0146]

[0147] in, Indicates time period The total power obtained by the grid-connected green hydrogen plant from the power grid, Indicates time period Downstream access bus Maximum available power at the location;

[0148] Among them, total power Represented as,

[0149]

[0150] in, , and They represent time periods respectively. The power of the PEM electrolyzer, the power of the compressor, and the power of the battery energy storage system;

[0151] Busbar Maximum available power at the location It is obtained by weighted averaging of the maximum available power at the access point under each renewable energy combination state, and is expressed as follows:

[0152]

[0153] in, Indicates time period Next combination state The probability, Represents the combination state Next period The maximum available power of the access point, This represents the number of discrete states for solar irradiance and wind speed within a given time period.

[0154] When a grid-connected green hydrogen plant is required to produce pure green hydrogen using only renewable energy, the maximum available power at the access point is further satisfied.

[0155]

[0156] in, and Representing the combination states respectively Time period Next The first photovoltaic power station and the first Available power of a wind farm and These represent the number of photovoltaic power plants and wind farms, respectively. Represents a sufficiently large positive number. This represents a Boolean variable; when pure green hydrogen production is required, ;otherwise, .

[0157] The model solving module solves the optimization planning model to obtain the optimal configuration result that meets the requirements for safe operation, including:

[0158] The optimal configuration result includes at least the optimal values ​​of the internal parameters of the PEM electrolyzer, the capacity configuration results of each device, and the corresponding economic evaluation results.

[0159] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor; the processor executes the computer program to implement the steps of the method as claimed in any one of claims 1 to 9.

[0160] A computer-readable storage medium storing a computer program; the computer program, when executed by a processor, implements the steps of the method as claimed in any one of claims 1 to 9.

[0161] Compared with existing technologies, the significant advantages of this invention, when adopting the above scheme, are as follows: Incorporating the internal parameters of the PEM electrolyzer as optimization variables into the system-level planning of the grid-connected green hydrogen plant allows for a more realistic reflection of the electrolyzer's operating characteristics, improving the rationality of the green hydrogen plant configuration. Simultaneously, by introducing hydrogen content constraints in oxygen, the electrolyzer can be prevented from entering unsafe operating ranges under low current density conditions, enhancing the engineering feasibility of the optimization results. Furthermore, incorporating the battery energy storage system as a collaborative unit into the optimization framework can smooth out input power fluctuations and improve the overall system economy, thus providing a valid basis for the design, planning, and investment decisions of the grid-connected green hydrogen plant.

[0162] The calculation results show that the present invention can obtain the optimal configuration scheme for grid-connected green hydrogen plants while meeting the requirements for safe operation. Compared with the baseline operating conditions, the system configuration is more reasonable after considering the optimization of the internal parameters of the PEM electrolyzer and safety constraints, and the levelized cost of hydrogen is reduced. The system economy can be further improved by further configuring the battery energy storage system. Attached Figure Description

[0163] Figure 1 This is a schematic diagram of the grid-connected green hydrogen plant system of the present invention.

[0164] Figure 2 This is a schematic diagram of the optimized design framework for the grid-connected green hydrogen plant of the present invention.

[0165] Figure 3 This is a comparison chart of input power and electrolytic cell power in calculation examples A and B of this invention.

[0166] Figure 4 This is a comparison chart of the hydrogen content in oxygen in calculation examples A and B of this invention.

[0167] Figure 5 The curves showing the input power versus the electrolytic cell power in example C of this invention are shown.

[0168] Figure 6This is a comparison curve of the efficiency of example B and example C in this invention. Detailed Implementation

[0169] The technical solution and beneficial effects of the present invention will be described in detail below with reference to the accompanying drawings.

[0170] This embodiment provides an optimization planning method for grid-connected green hydrogen plants that considers electrolyzer parameters and safety constraints. The method includes:

[0171] (1) Obtaining input data for grid-connected green hydrogen plants: The input data mainly includes hydrogen demand data, electricity price data or electricity price scenario data, renewable energy output data, available power boundary data for grid connection, equipment investment and operating cost parameters, and electrolyzer safety threshold parameters. The above data together constitute the basic input conditions for the subsequent optimization planning model.

[0172] During the research period, the green hydrogen plant needs to meet hourly hydrogen demand. Let the set of time periods be denoted as . Then the time period The hydrogen demand is denoted as:

[0173] (1)

[0174] In the formula, Indicates time period The demand for hydrogen.

[0175] In practical applications, this demand data can be obtained from historical statistical results, forecast curves, or typical daily load curves of hydrogen refueling stations, industrial users, or other end-user hydrogen consumption scenarios, and then uniformly discretized to the same time scale.

[0176] Considering that electricity purchase prices under grid-connected operation conditions are typically time-varying and uncertain, this embodiment further constructs an electricity price scenario. Let the... Electricity pricing scenarios during time periods The electricity purchase price is as follows:

[0177] (2)

[0178] The corresponding scenario probability is denoted as:

[0179] (3)

[0180] The probability of the scenario can then be expressed as the average of the probabilities over each time period, i.e.:

[0181] (4)

[0182] In the formula, Indicates the first The probability of each electricity price scenario. Indicates the first The scene in time period The probability of electricity price decline This represents the total number of study periods; , This represents the Monte Carlo scene set.

[0183] In practice, probability distribution functions for each time period can be constructed based on historical time-of-use electricity price data, and multiple electricity price scenarios can be generated using the Monte Carlo method to reflect the changes in the operating costs of the green hydrogen plant under different electricity purchase conditions.

[0184] For grid-connected green hydrogen plants, the renewable energy output status is also a crucial external boundary affecting optimization results. To describe the fluctuation characteristics of wind and solar power resources at different time periods, this embodiment discretizes solar irradiance and wind speed into several states, and the renewable energy output data includes time-series scenario data of solar irradiance and wind speed. Let time periods be defined. Next The solar irradiance state is recorded as follows:

[0185] (5)

[0186] Time period Next Each wind speed state is recorded as:

[0187] (6)

[0188] Under the assumption that solar irradiance and wind speed are independent, the combined state During the period The probability of this can be written as:

[0189] (7)

[0190] In the formula, Represents the combination state During the period The probability, and These represent the probability of occurrence of solar irradiance state and wind speed state, respectively.

[0191] Using the above methods, typical daily wind speed curves and solar irradiance curves can be extracted from historical meteorological data, and further renewable energy combination scenarios can be formed for optimization calculations.

[0192] The available power boundary data for grid connection is constructed using the maximum available power at the connection point. In a grid-connected scenario, the green hydrogen plant cannot obtain unlimited power from the connection point; its hourly available power is also constrained by the operating conditions of the connection bus and the output of renewable energy sources. Let the connection bus of the grid-connected green hydrogen plant be... Then the time period The maximum available power of the downstream access point is denoted as:

[0193] (8)

[0194] This quantity can be obtained by weighted average of the maximum available power at the point of access under each renewable energy combination state, that is:

[0195] (9)

[0196] In the formula, Represents the combination state Next period The maximum available power of the access point, This represents the discrete state number of solar irradiance and wind speed at each time period.

[0197] When a grid-connected green hydrogen plant is required to produce pure green hydrogen using only renewable energy, the maximum available power at the connection point must further meet the total output limit of renewable energy, namely:

[0198] (10)

[0199] In the formula, and Representing the combination states respectively Time period Next The first photovoltaic power station and the first The available power of a wind farm; and These are the numbers of photovoltaic power plants and wind farms, respectively. It is a sufficiently large positive number; This is a Boolean variable. When the requirement is for the production of pure green hydrogen, ;otherwise, .

[0200] This allows us to obtain the available power boundaries for each time period within the study period, which can then be used as important input constraints in subsequent optimization models.

[0201] In addition to external boundary data, the model also requires equipment cost parameters. These parameters must include at least the investment cost per unit capacity of the PEM electrolyzer. Investment cost per unit capacity of battery energy storage system Investment cost per unit capacity of power converter investment cost per unit capacity of compressor and the unit capacity investment cost of hydrogen storage devices At the same time, the unit operating cost of hydrogen production also needs to be specified. Hydrogen storage operating costs Electrolytic cell operating costs and compressor operating costs These parameters can be determined based on equipment manufacturer data, market price information, engineering experience values, or project feasibility study data, and uniformly converted to the research period and corresponding capacity units to facilitate the subsequent construction of the objective function.

[0202] In addition, to ensure the safe operation of the electrolyzer, the maximum allowable value of hydrogen content in oxygen must be predetermined as a safety threshold parameter for the electrolyzer, denoted as:

[0203] (11)

[0204] This parameter will be used in subsequent safety constraints to limit the hydrogen gas fraction in oxygen in the PEM electrolyzer to not exceed a preset safety boundary under different operating conditions, thereby avoiding the safety risks caused by enhanced hydrogen cross-permeability under low current density operating conditions.

[0205] (2) Establish an optimization planning model for grid-connected green hydrogen plants: This model addresses the overall system configuration problem, comprehensively considers the capacity selection and coordinated matching of key equipment such as PEM electrolyzers, power converters, compressors, hydrogen storage devices, and optional battery energy storage systems, and is used to jointly determine the optimal configuration parameters of each component unit. It also optimizes the design scheme of grid-connected green hydrogen plants within the research period by combining hydrogen demand, electricity price scenarios, grid access capabilities, and renewable energy output conditions.

[0206] like Figure 3 As shown, the optimization planning model mainly consists of two parts: a minimization module and a PEM electrolyzer model module. The minimization module determines the system design and operating variables based on hydrogen demand, electricity price scenarios, available power boundaries at the connection point, and relevant cost parameters. The PEM electrolyzer model module calculates the electrolysis efficiency, cross-penetration level, and safety boundary based on given internal parameters and feeds the results back to the minimization module. The two parts are coupled during the solution process, thereby achieving system-level collaborative optimization of the grid-connected green hydrogen plant.

[0207] In this embodiment, the design variables mainly include the internal parameters of the PEM electrolyzer and the capacity parameters of each piece of equipment. Among these, the internal parameters of the PEM electrolyzer include film thickness. Cathode pressure and battery area Equipment capacity parameters include the rated power of the PEM electrolyzer. Rated power of power converter Compressor rated power Hydrogen storage device capacity and the rated power of optional battery energy storage systems and rated capacity .

[0208] Operating variables are used to describe the operating status of the system at different times, mainly including the power of the PEM electrolyzer. Compressor power Battery energy storage system power Hydrogen production flow rate Hydrogen storage flow rate Hydrogen storage state and state of charge Given the design variables, the above operating variables change with variations in hydrogen demand, electricity price, and available power boundary, and together determine the system's operating mode and economic outcome during the study period.

[0209] The total power obtained by the grid-connected green hydrogen plant from the power grid is determined by the electrolyzer, compressor, and battery energy storage system, and can be expressed as:

[0210] (12)

[0211] In the formula, Indicates time period The total power drawn from the grid. When When the battery is charging, it indicates that the battery energy storage system is in a charging state; when When this time, it indicates that the battery energy storage system is in a discharging state.

[0212] Based on the above, this embodiment incorporates the internal parameters of the PEM electrolyzer and the system equipment capacity parameters into a unified optimization framework. Subsequently, by combining the objective function and various constraints, a complete optimization planning model for the grid-connected green hydrogen plant is formed to solve for the optimal configuration scheme that meets the requirements for safe operation.

[0213] (3) Construct a steady-state model of the PEM electrolyzer to characterize the relationship between the internal parameters, which are decision variables, and the efficiency and safe operating boundary of the electrolyzer: According to the Nernst equation, the minimum theoretical decomposition voltage required for water electrolysis is related to the cell temperature and gas partial pressure, which can be expressed as:

[0214] (13)

[0215] In the formula, Represents Nernst voltage. Indicates battery temperature. Represents the gas constant. Denotes Faraday's constant. and These represent the partial pressures of oxygen and hydrogen, respectively. This indicates the standard pressure. This voltage reflects the theoretical decomposition conditions required for the water electrolysis process.

[0216] In addition to the theoretical decomposition voltage, PEM electrolyzers also experience activation overvoltage and ohmic losses during operation. Since the operating current density is typically much greater than the exchange current density, the activation overvoltage can be expressed using the Tafel equation:

[0217] (14)

[0218] In the formula, Indicates activation overvoltage. Represents the charge transfer coefficient. Indicates the number of electrons transferred. Indicates the operating current density. This represents the exchange current density.

[0219] The membrane separates the PEM electrolyzer into an anode and a cathode, and its conductivity directly affects the ohmic loss. Considering the membrane thickness and conductivity, the ohmic voltage loss can be written as:

[0220] (15)

[0221] In the formula, Indicates ohmic voltage loss. Indicates additional resistance. Indicates the coefficient of membrane expansion. Indicates membrane conductivity, This represents water activity. Therefore, the total voltage of a single cell can be expressed as:

[0222] (16)

[0223] The above relationship indicates that film thickness It not only affects the cross-penetration process, but also affects the electrolyzer voltage and overall efficiency through ohmic losses.

[0224] In actual operation, hydrogen production and oxygen production will cross-permeate through the membrane. The equivalent current density corresponding to hydrogen cross-permeation can be expressed as:

[0225] (17)

[0226] In the formula, This represents the equivalent current density of hydrogen cross-permeation. Denotes Faraday's constant. This indicates hydrogen permeability in relation to temperature. Indicates the coefficient of membrane expansion. This represents the cross-penetration current density constant. This represents the operating current density. It can be seen that the cathode pressure... Increase or film thickness Decreasing the oxygen permeability coefficient enhances the hydrogen cross-permeability effect. For Nafion membranes, the oxygen permeability coefficient is approximately twice that of hydrogen; therefore, the total cross-permeability equivalent current density can be further written as:

[0227] (18)

[0228] From a safety perspective, the cross-permeability effect is more pronounced when operating at low current densities, which may lead to an increase in the hydrogen content in oxygen. The integral of hydrogen in oxygen can be expressed as:

[0229] (19)

[0230] In the formula, This represents the integral of hydrogen gas in oxygen. In actual operation, this value needs to be limited to a safe range, otherwise it will lead to the shutdown of the electrolyzer. Therefore, in this embodiment, this quantity is not only the output of the PEM electrolyzer model, but also an important basis for the subsequent construction of safety constraints.

[0231] The efficiency of a PEM electrolyzer is determined by both hydrogen production efficiency and Faraday efficiency. Hydrogen production efficiency reflects the combined effects of electrical and thermal power losses, while Faraday efficiency reflects the efficiency loss caused by cross-penetration. The electrolyzer efficiency can be written as:

[0232] (20)

[0233] In the formula, Indicates hydrogen production efficiency. Indicates Faraday efficiency. This represents the efficiency of the electrolyzer. Considering the compression process, a total efficiency expression incorporating the compressor's influence can also be obtained. Therefore, the efficiency of the electrolyzer is not a fixed constant, but rather varies with operating current density, film thickness, cathode pressure, and operating conditions.

[0234] Based on the aforementioned steady-state model, the influence of internal parameters on the overall performance of the PEM electrolyzer is further analyzed. The results show that cathode pressure, film thickness, and cell area all have a significant impact on the efficiency curve and the safe operating range. When the cathode pressure increases, hydrogen cross-permeation in the low current density region is enhanced, leading to a decrease in overall efficiency. While increasing film thickness helps suppress permeation losses, it exacerbates ohmic losses in the high current density region. Cell area not only affects the shape of the efficiency curve but also alters the safe operating range under low load conditions. Particularly with a smaller cell area, the electrolyzer can maintain a higher current density at a lower actual current, thereby reducing permeation losses and improving safety under low load conditions.

[0235] Therefore, in this embodiment, the PEM electrolyzer is no longer simplified into a fixed-efficiency device, but rather the film thickness is... Cathode pressure and battery area As internal parameter decision variables, they are incorporated into the optimization planning model along with the capacity parameters of other equipment in the system. In this way, the impact of internal parameters on efficiency, cross-penetration, and safety boundaries can be reflected simultaneously, thus providing a more practical model basis for the system-level optimization of subsequent grid-connected green hydrogen plants.

[0236] (4) Establish an objective function with the goal of minimizing the levelized cost of hydrogen: The levelized cost of hydrogen can comprehensively reflect the impact of factors such as equipment investment, operating expenses, equipment degradation and subsidy mechanisms on the unit cost of hydrogen, and is therefore suitable as an overall economic evaluation index for system configuration problems.

[0237] Let the levelized cost of hydrogen be denoted as . Then its expression is:

[0238] (twenty one)

[0239] In the formula, Indicates system capital expenditure, Indicates the first Operating expenses under different electricity pricing scenarios This represents the probability of the corresponding electricity price scenario. Indicates the cost of equipment degradation. Indicates subsidy items, This indicates the total hydrogen demand during the research period. The subsidy item... The objective function, determined based on the unit hydrogen subsidy and the hydrogen demand during the research period, is used to characterize the impact of the subsidy mechanism on the optimal configuration of grid-connected green hydrogen plants. As can be seen from the above formula, the objective function essentially measures the merits of the system configuration scheme by using the ratio of total cost to total hydrogen supply.

[0240] The system capital expenditure consists of the configuration costs of the PEM electrolyzer, battery energy storage system, power converter, compressor, and hydrogen storage device, which can be written as:

[0241] (twenty two)

[0242] In the formula, , , and These represent the rated capacities of the PEM electrolyzer, battery energy storage system, power converter, and compressor, respectively. Indicates the capacity of the hydrogen storage device. , , , and These represent the unit capacity investment cost of the corresponding equipment. It can be seen that the selection of design variables directly affects the initial investment level of the system; therefore, there is a direct coupling relationship between the equipment configuration scheme and the economic objective.

[0243] Operating expenses are calculated using a scenario-weighted approach. Let the first... Operating expenses under a specific electricity price scenario are: Then we have:

[0244] (twenty three)

[0245] In the formula, Indicates time period Total power purchased from the grid, Indicates the first Electricity pricing scenarios and time periods The electricity purchase price, Indicates time period Hydrogen production flow rate, Indicates time period Hydrogen storage flow rate, , , and These represent the unit cost of hydrogen production, the cost of hydrogen storage, the operating cost of the electrolyzer, and the operating cost of the compressor, respectively. This cost component reflects the hourly operating characteristics of the grid-connected green hydrogen plant during the study period, and also allows electricity price fluctuations, electricity consumption patterns, and equipment operating status to be reflected in the objective function.

[0246] In addition to investment and operating costs, this embodiment further considers the impact of equipment degradation on the system's economics. For PEM electrolyzers and battery energy storage systems, the degradation cost can be written as:

[0247] (twenty four)

[0248] In the formula, Indicates time period The power of the battery energy storage system, Indicates time period The unit degradation cost of battery energy storage systems Indicates time period PEM electrolytic cell power, This represents the unit degradation cost of the PEM electrolyzer. Introducing this part into the objective function avoids the optimization model from focusing solely on short-term operating costs while ignoring equipment lifespan losses, thus making the resulting configuration more consistent with engineering realities.

[0249] (5) Establishing constraints: The constraints mainly reflect the limitations on the optimization results by the operating boundary of the PEM electrolyzer, the relationship between hydrogen production and storage, the operating range of the battery energy storage system, and the grid connection capability.

[0250] First, the PEM electrolyzer must meet basic operating boundaries during the optimization process. (Time period is set.) The power of the lower PEM electrolyzer is Therefore, its operating limit is jointly limited by the maximum allowable current density and the battery area, which can be written as:

[0251] (25)

[0252] In the formula, This indicates the maximum allowable current density of the electrolytic cell. This indicates the rated voltage of the PEM electrolytic cell. This indicates the battery area. At the same time, the battery area and cathode pressure themselves also need to be limited to selectable ranges, namely:

[0253] (26)

[0254] (27)

[0255] In the formula, and These represent the lower and upper limits of the battery area, respectively. and These represent the lower and upper limits of the cathode pressure, respectively. These constraints ensure that the internal parameters and operating conditions remain within the equipment's allowable range.

[0256] In addition to operating boundaries, the PEM electrolyzer must also meet safety constraints. These safety constraints are designed to prevent the PEM electrolyzer from entering an unsafe operating range under low current density conditions due to increased hydrogen cross-permeability, thereby ensuring that subsequent optimization results meet engineering feasibility requirements. As shown in the aforementioned steady-state model, the cross-permeability effect is enhanced during low current density operation, easily leading to an increase in the hydrogen content in oxygen. Therefore, in this embodiment, the hydrogen integral in oxygen is limited to:

[0257] (28)

[0258] In the formula, Indicates time period The integral number of hydrogen gas in oxygen gas. This represents the maximum permissible hydrogen content in oxygen. By introducing this constraint, we can avoid obtaining configuration results that, while economical, do not meet safety requirements during the optimization planning phase.

[0259] On the hydrogen side, the operation of hydrogen production from the electrolyzer and the hydrogen storage unit jointly determine whether the system can meet hourly demand. The hydrogen production flow rate can be determined by the electrolyzer power and efficiency, i.e.:

[0260] (29)

[0261] In the formula, Indicates the time period of the PEM electrolyzer. Hydrogen production flow rate, Indicates time period PEM electrolytic cell power, Indicates time period The efficiency of the electrolytic cell This indicates the lower heating value of hydrogen. Hydrogen storage devices need to meet capacity limits during operation, which are determined by time periods. The state is denoted as Then we have:

[0262] (30)

[0263] In the formula, and Let represent the lower and upper limits of the hydrogen storage state, respectively. Considering hydrogen storage loss and the hourly charging / discharging process, the hydrogen storage state can be expressed as:

[0264] (31)

[0265] In the formula, This represents the loss coefficient of the hydrogen storage device. and They represent time periods respectively. and time period Hydrogen storage flow rate, This indicates the capacity of the hydrogen storage device. To ensure that hydrogen demand is met at all times, the hydrogen supply and demand of grid-connected green hydrogen plants should also maintain a hydrogen balance relationship at each time period:

[0266] (32)

[0267] In the formula, Indicates time period The above relationship reflects the dynamic coupling between hydrogen production through electrolysis, hydrogen storage and regulation, and end-user demand.

[0268] When configuring a battery energy storage system, its operation also needs to be constrained. (Time period setting) The state of charge is as follows Then its operating range satisfies:

[0269] (33)

[0270] In the formula, and Let represent the upper and lower limits of the state of charge, respectively. Considering the charging and discharging efficiency and self-loss of the energy storage system, its state update can be expressed as:

[0271] (34)

[0272] In the formula, This represents the self-loss coefficient of the battery energy storage system. Indicates the charge and discharge efficiency of the battery energy storage system; Indicates time period The energy storage capacity, where, when When the battery is charging, it indicates that the battery energy storage system is in a charging state; when When this time, it indicates that the battery energy storage system is in a discharging state; This indicates the rated capacity of the battery energy storage system. This allows us to distinguish whether the energy storage system is charging or discharging at different times, and to coordinate its operation with the power regulation of the electrolyzer and compressor.

[0273] The battery energy storage system configuration constraints include state of charge constraints, state of charge / discharge update constraints, and battery energy storage system configuration constraints, which are used to determine the rated power of the battery energy storage system. and rated capacity It is also optimized in conjunction with the configuration parameters of the PEM electrolyzer, compressor, power converter and hydrogen storage device.

[0274] Furthermore, the design of grid-connected green hydrogen plants is also constrained by their grid connection capabilities. (Time period) The total power obtained by the grid-connected green hydrogen plant from the power grid is Then it satisfies:

[0275] (35)

[0276] In the formula, Indicates connection to the busbar Period The maximum available power. The total system power is determined by the electrolyzer, compressor, and energy storage system, namely:

[0277] (36)

[0278] In the formula, , and They represent time periods respectively. The power of the PEM electrolyzer, the power of the compressor, and the power of the battery energy storage system.

[0279] Therefore, the maximum available power boundary at the access point simultaneously restricts the operational space for hydrogen electrolysis, hydrogen compression, and energy storage regulation. When the system is required to produce pure green hydrogen using only renewable energy sources, the maximum available power at the access point must be further constrained by the total available output of wind and solar power, thus enabling the optimization results to reflect a more stringent power supply boundary under the pure green hydrogen scenario.

[0280] (6) Optimization and Result Output: The model uses the internal parameters of the PEM electrolyzer and the system equipment capacity parameters as optimization variables, and performs joint solutions for the operating status of each time period within the study period. Since the model simultaneously includes efficiency calculation, safety boundary determination, hydrogen storage state update, battery energy storage system state evolution, and grid connection constraints, it is a multivariate coupled nonlinear optimization problem.

[0281] In the solution process, firstly, based on the given film thickness... Cathode pressure and battery area The electrolyzer efficiency at each time period was calculated using the aforementioned PEM electrolyzer steady-state model. and the integral of hydrogen gas in oxygen Subsequently, these values ​​were substituted into the objective function and constraints, and combined with the rated power of the PEM electrolyzer. Rated power of power converter Compressor rated power Hydrogen storage device capacity and the rated power of optional battery energy storage systems and rated capacity It provides a unified solution for system configuration and hourly operating status.

[0282] During the solution process, the model must simultaneously satisfy conditions such as the PEM electrolyzer operating boundary, safety constraints, hydrogen balance relationship, battery energy storage system operating range, and maximum available power boundary at the access point. Only when these constraints are met is the obtained configuration scheme considered a feasible solution; among all feasible solutions, the hydrogen levelized cost is selected. The smallest solution is considered the optimal configuration.

[0283] After the solution is completed, the optimal internal parameters and equipment capacity configuration results of the grid-connected green hydrogen plant can be obtained, including the membrane thickness. Cathode pressure Battery area Rated power of PEM electrolytic cell Rated power of power converter Compressor rated power Hydrogen storage device capacity and the rated power of optional battery energy storage systems and rated capacity Furthermore, the electrolytic cell power at different time periods can be obtained. Compressor power Battery energy storage system power Hydrogen production flow rate Hydrogen storage state and state of charge Based on this, the levelized cost of hydrogen under the corresponding scheme is calculated. .

[0284] The optimal configuration results are used to characterize the optimal equipment selection and operation configuration scheme of the grid-connected green hydrogen plant under given hydrogen demand, electricity price scenarios, renewable energy output, grid access boundary and safety threshold conditions.

[0285] Example explanation:

[0286] To verify the effectiveness of the grid-connected green hydrogen plant optimization planning method described in this invention, which considers internal parameters of the electrolyzer, safety constraints, and energy storage synergy, the IEEE 30-node test system was selected as the research object, and a typical new energy base scenario was constructed based on it. Considering the abundant wind and solar resources in Northwest China, two wind farms and one photovoltaic power station were set up in the system, with the green hydrogen plant connected to bus 18.

[0287] To illustrate the impact of the method of this invention on the system configuration results, three case studies are set up, the summary of which is shown in Table 1.

[0288]

[0289] Among them, Case A is the baseline operating condition, which adopts a detailed PEME model, but the internal parameters are taken as preset values, and safety constraints and BESS are not considered; Case B is based on Case A and further considers the optimization of PEME internal parameters and safety constraints; Case C is based on Case B and configured with BESS to illustrate the impact of energy storage collaboration on the system design results.

[0290] In constructing the new energy scenario, a time-series input scenario is formed using typical daily wind speed and solar irradiance curves for four seasons in a typical region. The operational boundary within the study period is constructed by combining typical daily electricity load curves and hydrogen demand curves. Simultaneously, an electricity price scenario is constructed based on typical time-of-use electricity price characteristics, and a sequential quadratic programming method is used to solve the optimization model.

[0291] To analyze the impact of PEME internal parameter optimization and safety constraints on the design results of grid-connected green hydrogen plants, we first compared case A and case B, and the results are shown in Table 2.

[0292]

[0293] Table 2 shows that after introducing PEME internal parameter optimization and safety constraints, the capacity of the main system equipment and the levelized cost of hydrogen both decreased. Compared with Example A, the rated capacity of the electrolyzer, power converter, and compressor in Example B was reduced, and the cost of LCOH decreased from 33.8 yuan / kg to 31.6 yuan / kg. This indicates that incorporating film thickness, cathode pressure, and battery area into the optimization variables helps to improve the rationality of system configuration and enhance overall economic efficiency.

[0294] Based on the comparison between Case A and Case B, the accompanying drawings further provide the input power and electrolyzer power curves under two operating conditions, as well as the hydrogen content variation curve in the oxygen. As can be seen from the drawings, after introducing PEME internal parameter optimization and safety constraints, the system power distribution is more reasonable, and the hydrogen content in the oxygen can be limited to a safe range, thus verifying the effectiveness of this invention in improving system economy and ensuring the safe operation of the electrolyzer.

[0295] To further analyze the impact of energy storage system configuration on the design results of the green hydrogen plant, case studies B and C were compared, and the results are shown in the table below.

[0296]

[0297] Table 3 shows that the optimal system configuration further changed after the introduction of BESS. Compared with Case B, Case C saw a further decrease in the rated power of the electrolyzer and compressor, an increase in the power converter capacity, and the addition of BESS, resulting in a further reduction in LCOH cost from 31.6 yuan / kg to 29.8 yuan / kg. This indicates that BESS can perform some power regulation and energy buffering functions, thereby improving the system's economics. Simultaneously, the optimal membrane thickness and cathode pressure also changed, demonstrating that the configuration of the energy storage system further influences the optimal selection of PEME internal parameters.

[0298] For examples B and C, in addition to the configuration results shown in Table 3, the accompanying drawings also provide the input power and electrolyzer power curves for example C, as well as the efficiency comparison curves for examples B and C. As can be seen from the drawings, after configuring BESS, some of the fluctuating power is handled by the energy storage system, improving the electrolyzer's operating status and further enhancing the overall system efficiency and economy. This demonstrates that the synergistic effect of energy storage has a positive impact on the optimized design of grid-connected green hydrogen plants.

[0299] This invention also provides an optimization planning system for grid-connected green hydrogen plants that considers electrolyzer parameters and safety constraints, including:

[0300] The optimization planning model building module is configured to build an optimization planning model based on the operating parameters of the grid-connected green hydrogen plant;

[0301] The electrolyzer steady-state model construction module is configured to construct a PEM electrolyzer steady-state model, using the internal parameters of the PEM electrolyzer as decision variables for the optimization planning model; wherein, the internal parameters of the electrolyzer include film thickness, cathode pressure, and cell area; and,

[0302] The model solving module is configured to take the minimum hydrogen levelized cost as the objective function, establish constraints including electrolyzer operation constraints, safety constraints, hydrogen production and storage constraints, battery energy storage system operation constraints, and grid connection constraints, and solve the optimization planning model to obtain the optimal configuration result that meets the safety operation requirements.

[0303] This invention also provides another PCIe-based FPGA time stamp acquisition device. Figure 5 This is a schematic diagram of the structure of a PCIe-based FPGA time-stamp acquisition device in an embodiment of the present invention. Figure 5 As shown, the PCIe-based FPGA time-stamp acquisition device 50 includes: a processor 501 and a memory 502 configured to store a computer program capable of running on the processor;

[0304] When the processor 501 is configured to run a computer program, it executes the method steps described in the foregoing embodiments.

[0305] Of course, in practical applications, such as Figure 5 As shown, the various components in this data exchange device are coupled together via a bus system 503. It can be understood that the bus system 503 is used to implement communication between these components. In addition to a data bus, the bus system 503 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 5 The general designated all buses as Bus System 503.

[0306] In practical applications, the aforementioned processor includes a Field-Programmable Gate Array (FPGA), and the processor can be a Central Processing Unit (CPU) or a Digital Signal Processor (DSP). It is understood that for different devices, the electronic devices used to implement the above-mentioned processor functions can also be other types, and this embodiment of the invention does not impose specific limitations.

[0307] The aforementioned memory can be volatile memory, such as random-access memory (RAM); or non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state drive (SSD); or a combination of the above types of memory, and provides instructions and data to the processor.

[0308] In an exemplary embodiment, the present invention also provides a computer-readable storage medium for storing a computer program.

[0309] Optionally, the computer-readable storage medium can be applied to any of the methods in the embodiments of the present invention, and the computer program causes the computer to execute the corresponding processes implemented by the processor in the various methods of the embodiments of the present invention. For the sake of brevity, these will not be described in detail here.

[0310] In the several embodiments provided by this invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0311] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can 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 code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0312] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0313] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0314] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0315] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0316] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for optimizing the planning of a grid-connected green hydrogen plant, considering electrolyzer parameters and safety constraints, characterized in that: include, Based on the operating parameters of the grid-connected green hydrogen plant, an optimization planning model is constructed; A steady-state model of a PEM electrolyzer is constructed, with the internal parameters of the PEM electrolyzer used as decision variables for the optimization planning model; wherein, the internal parameters of the electrolyzer include film thickness, cathode pressure, and cell area; Using the minimum levelized cost of hydrogen as the objective function, constraints including electrolyzer operation constraints, safety constraints, hydrogen production and storage constraints, battery energy storage system operation constraints, and grid connection constraints are established. The optimization planning model is then solved to obtain the optimal configuration result that meets the requirements of safe operation.

2. The method as described in claim 1, characterized in that: The operating parameters of the grid-connected green hydrogen plant include hydrogen demand data, electricity price scenario data, renewable energy output data, available power boundary data for grid connection, equipment cost parameters, and electrolyzer safety threshold parameters. Among them, hydrogen demand data is defined as the hourly hydrogen demand sequence within the study period; electricity price scenario data is constructed from historical electricity price data; renewable energy output data includes time-series scenario data of solar irradiance and wind speed; and available power boundary data for grid connection is constructed from the maximum available power at the connection point. Equipment cost parameters include at least the unit investment cost of the PEM electrolyzer, the unit investment cost of the battery energy storage system, the unit investment cost of the power converter, the unit investment cost of the compressor, and the unit investment cost of the hydrogen storage device, as well as the corresponding operating cost parameters. Electrolyzer safety threshold parameters include the maximum allowable value of hydrogen content in oxygen.

3. The method as described in claim 1, characterized in that: A steady-state model of the PEM electrolyzer is constructed, using the internal parameters of the PEM electrolyzer as the decision variables of the optimization planning model. include, Construct a steady-state model of the PEM electrolyzer, and determine the film thickness. Cathode pressure and battery area As an internal parameter to be optimized; The PEM electrolyzer steady-state model is used to characterize the relationship between the internal parameters and the electrolyzer efficiency and safe operating boundaries; wherein, the hydrogen cross-permeation equivalent current density is expressed as... ， in, This represents the equivalent current density of hydrogen cross-permeation. Denotes Faraday's constant. This indicates the hydrogen permeability in relation to temperature. Indicates the coefficient of membrane expansion. This represents the cross-penetration current density constant. Indicates the operating current density; The hydrogen content in oxygen is expressed as... ， in, This represents the integral of hydrogen gas in oxygen. The efficiency of a PEM electrolyzer is expressed as follows: ， in, Indicates the efficiency of the electrolytic cell. Indicates hydrogen production efficiency. Indicates Faraday efficiency; The internal parameters are used as decision variables in the optimization planning model. They are jointly optimized with the rated power of the PEM electrolyzer, the rated power of the compressor, the capacity of the hydrogen storage device, and the configuration parameters of the battery energy storage system to determine the optimal configuration scheme for the grid-connected green hydrogen plant.

4. The method as described in claim 1, characterized in that: The objective function is to minimize the levelized cost of hydrogen, which is expressed as: ， in, This represents the levelized cost of hydrogen. Indicates capital expenditure, Indicates the first Operating expenses under different electricity pricing scenarios Indicates the first The probability of each electricity price scenario. Indicates the cost of equipment degradation. Indicates subsidy items, This indicates the total hydrogen demand during the research period; Wherein, the system capital expenditure is expressed as, ， in, , , and These represent the rated capacities of the PEM electrolyzer, battery energy storage system, power converter, and compressor, respectively. Indicates the capacity of the hydrogen storage device. , , , and These represent the unit capacity investment cost of the corresponding equipment; No. Operating expenses under individual electricity pricing scenarios Represented as, ， in, For time period sets, Indicates time period Total power purchased from the grid, Indicates the first Electricity pricing scenarios and time periods The electricity purchase price; Indicates time period Hydrogen production flow rate, Indicates time period Hydrogen storage flow rate, Indicates time period PEM electrolytic cell power, Indicates time period The compressor power; , , and These represent the unit cost of hydrogen production, the cost of hydrogen storage, the operating cost of the electrolyzer, and the operating cost of the compressor, respectively. Equipment degradation costs Represented as, ， in, Indicates time period The power of the battery energy storage system, Indicates time period The unit degradation cost of battery energy storage systems This indicates the unit degradation cost of a PEM electrolyzer; Subsidy The amount is determined based on the unit's hydrogen subsidy and the hydrogen demand during the research period.

5. The method as described in claim 1, characterized in that: Electrolyzer operating constraints include power constraints, cell area constraints, and cathode pressure constraints, which are expressed as follows: ， ， ， in, Indicates time period PEM electrolytic cell power, Indicates the maximum allowable current density. This indicates the rated voltage of the PEM electrolyzer. Indicates the battery area. Indicates cathode pressure; and These represent the lower and upper limits of the battery area, respectively. and These represent the lower and upper limits of the cathode pressure, respectively. Safety constraints are represented as follows: ， in, Indicates time period The integral number of hydrogen gas in oxygen gas. This indicates the maximum permissible hydrogen content in oxygen.

6. The method as described in claim 1, characterized in that: Constraints on hydrogen production and storage include hydrogen production flow rate constraints, hydrogen storage state constraints, and hydrogen balance constraints. Among them, the PEM electrolyzer is in the time period The hydrogen production flow rate is expressed as, ， in, Indicates time period Hydrogen production flow rate, Indicates time period PEM electrolytic cell power, Indicates time period The efficiency of PEM electrolyzers This indicates the lower heating value of hydrogen. Hydrogen storage devices during time periods The hydrogen storage state is satisfied. ， in, Indicates time period hydrogen storage state, and These represent the lower and upper limits of hydrogen storage conditions, respectively; The hydrogen storage state is expressed as follows: ， in, This represents the loss coefficient of the hydrogen storage device. and They represent time periods respectively. and time period Hydrogen storage flow rate, Indicates the capacity of the hydrogen storage device; The grid-connected green hydrogen plant maintains a balance between hydrogen supply and demand at different times. ， in, Indicates time period The demand for hydrogen.

7. The method as described in claim 1, characterized in that: The operational constraints of battery energy storage systems include state of charge constraints, state of charge / discharge update constraints, and battery energy storage system configuration constraints. Among them, battery energy storage systems during time periods The state of charge is satisfied. ， in, Indicates time period The state of charge, and These represent the upper and lower limits of the charged state, respectively; After considering the charging and discharging efficiency and self-loss of the battery energy storage system, the time period The state of charge is represented as, ， In the formula, This represents the self-loss coefficient of the battery energy storage system. This indicates the charge and discharge efficiency of the battery energy storage system. Indicates time period The power of the battery energy storage system, Indicates the rated capacity of the battery energy storage system; where, when When the battery is charging, it indicates that the battery energy storage system is in a charging state; when When this time, it indicates that the battery energy storage system is in a discharging state.

8. The method as described in claim 1, characterized in that: Establish grid access constraints, including, Assume the green hydrogen plant connected to the grid is connected to the busbar as follows: Then the time period The total power obtained by the grid-connected green hydrogen plant from the power grid is sufficient. ， in, Indicates time period The total power obtained by the grid-connected green hydrogen plant from the power grid, Indicates time period Downstream access bus Maximum available power at the location; Among them, total power Represented as, ， in, , and They represent time periods respectively. The power of the PEM electrolyzer, the power of the compressor, and the power of the battery energy storage system; Busbar Maximum available power at the location It is obtained by weighted averaging of the maximum available power at the access point under each renewable energy combination state, and is expressed as follows: ， in, Indicates time period Next combination state The probability, Represents the combination state Next period The maximum available power of the access point, This represents the number of discrete states for solar irradiance and wind speed within a given time period. When a grid-connected green hydrogen plant is required to produce pure green hydrogen using only renewable energy, the maximum available power at the access point is further satisfied. ， in, and Representing the combination states respectively Time period Next The first photovoltaic power station and the first Available power of a wind farm and These represent the number of photovoltaic power plants and wind farms, respectively. Represents a sufficiently large positive number. This represents a Boolean variable; when the production of pure green hydrogen is required, ;otherwise, .

9. The method as described in claim 1, characterized in that: Solving the optimization planning model yields the optimal configuration result that meets the requirements for safe operation, including: The optimal configuration result includes at least the optimal values ​​of the internal parameters of the PEM electrolyzer, the capacity configuration results of each device, and the corresponding economic evaluation results.

10. An optimization planning system for a grid-connected green hydrogen plant considering electrolyzer parameters and safety constraints, characterized in that: include, The optimization planning model building module is configured to build an optimization planning model based on the operating parameters of the grid-connected green hydrogen plant; The electrolyzer steady-state model construction module is configured to construct a PEM electrolyzer steady-state model, using the internal parameters of the PEM electrolyzer as decision variables for the optimization planning model; wherein, the internal parameters of the electrolyzer include film thickness, cathode pressure, and cell area; and, The model solving module is configured to take the minimum hydrogen levelized cost as the objective function, establish constraints including electrolyzer operation constraints, safety constraints, hydrogen production and storage constraints, battery energy storage system operation constraints, and grid connection constraints, and solve the optimization planning model to obtain the optimal configuration result that meets the safety operation requirements.

11. The system as described in claim 10, characterized in that: The operating parameters of the grid-connected green hydrogen plant include hydrogen demand data, electricity price scenario data, renewable energy output data, available power boundary data for grid connection, equipment cost parameters, and electrolyzer safety threshold parameters. Among them, hydrogen demand data is defined as the hourly hydrogen demand sequence within the study period; electricity price scenario data is constructed from historical electricity price data; renewable energy output data includes time-series scenario data of solar irradiance and wind speed; and available power boundary data for grid connection is constructed from the maximum available power at the connection point. Equipment cost parameters include at least the unit investment cost of the PEM electrolyzer, the unit investment cost of the battery energy storage system, the unit investment cost of the power converter, the unit investment cost of the compressor, and the unit investment cost of the hydrogen storage device, as well as the corresponding operating cost parameters. Electrolyzer safety threshold parameters include the maximum allowable value of hydrogen content in oxygen.

12. The system as described in claim 10, characterized in that: The steady-state model construction module for the electrolyzer constructs a steady-state model of the PEM electrolyzer, using the internal parameters of the PEM electrolyzer as the decision variables of the optimization planning model. include, Construct a steady-state model of the PEM electrolyzer, and determine the film thickness. Cathode pressure and battery area As an internal parameter to be optimized; The PEM electrolyzer steady-state model is used to characterize the relationship between the internal parameters and the electrolyzer efficiency and safe operating boundaries; wherein, the hydrogen cross-permeation equivalent current density is expressed as... ， in, This represents the equivalent current density of hydrogen cross-permeation. Denotes Faraday's constant. This indicates the hydrogen permeability in relation to temperature. Indicates the coefficient of membrane expansion. This represents the cross-penetration current density constant. Indicates the operating current density; The hydrogen content in oxygen is expressed as... ， in, This represents the integral of hydrogen gas in oxygen. The efficiency of a PEM electrolyzer is expressed as follows: ， in, Indicates the efficiency of the electrolytic cell. Indicates hydrogen production efficiency. Indicates Faraday efficiency; The internal parameters are used as decision variables in the optimization planning model. They are jointly optimized with the rated power of the PEM electrolyzer, the rated power of the compressor, the capacity of the hydrogen storage device, and the configuration parameters of the battery energy storage system to determine the optimal configuration scheme for the grid-connected green hydrogen plant.

13. The system as described in claim 10, characterized in that: The model solver module uses the minimum hydrogen levelization cost as the objective function, which is expressed as: ， in, This represents the levelized cost of hydrogen. Indicates capital expenditure, Indicates the first Operating expenses under different electricity pricing scenarios Indicates the first The probability of each electricity price scenario. Indicates the cost of equipment degradation. Indicates subsidy items, This indicates the total hydrogen demand during the research period; Wherein, the system capital expenditure is expressed as, ， in, , , and These represent the rated capacities of the PEM electrolyzer, battery energy storage system, power converter, and compressor, respectively. Indicates the capacity of the hydrogen storage device. , , , and These represent the unit capacity investment cost of the corresponding equipment; No. Operating expenses under individual electricity pricing scenarios Represented as, ， in, For time period sets, Indicates time period Total power purchased from the grid, Indicates the first Electricity pricing scenarios and time periods The electricity purchase price; Indicates time period Hydrogen production flow rate, Indicates time period Hydrogen storage flow rate, Indicates time period PEM electrolytic cell power, Indicates time period The compressor power; , , and These represent the unit cost of hydrogen production, the cost of hydrogen storage, the operating cost of the electrolyzer, and the operating cost of the compressor, respectively. Equipment degradation costs Represented as, ， in, Indicates time period The power of the battery energy storage system, Indicates time period The unit degradation cost of battery energy storage systems This indicates the unit degradation cost of a PEM electrolyzer; Subsidy The amount is determined based on the unit's hydrogen subsidy and the hydrogen demand during the research period.

14. The system as described in claim 10, characterized in that: Electrolyzer operating constraints include power constraints, cell area constraints, and cathode pressure constraints, which are expressed as follows: ， ， ， in, Indicates time period PEM electrolytic cell power, Indicates the maximum allowable current density. This indicates the rated voltage of the PEM electrolyzer. Indicates the battery area. Indicates cathode pressure; and These represent the lower and upper limits of the battery area, respectively. and These represent the lower and upper limits of the cathode pressure, respectively. Safety constraints are represented as follows: ， in, Indicates time period The integral number of hydrogen gas in oxygen gas. This indicates the maximum permissible hydrogen content in oxygen.

15. The system as described in claim 10, characterized in that: Constraints on hydrogen production and storage include hydrogen production flow rate constraints, hydrogen storage state constraints, and hydrogen balance constraints. Among them, the PEM electrolyzer is in the time period The hydrogen production flow rate is expressed as, ， in, Indicates time period Hydrogen production flow rate, Indicates time period PEM electrolytic cell power, Indicates time period The efficiency of PEM electrolyzers This indicates the lower heating value of hydrogen. Hydrogen storage devices during time periods The hydrogen storage state is satisfied. ， in, Indicates time period hydrogen storage state, and These represent the lower and upper limits of hydrogen storage conditions, respectively; The hydrogen storage state is expressed as follows: ， in, This represents the loss coefficient of the hydrogen storage device. and They represent time periods respectively. and time period Hydrogen storage flow rate, Indicates the capacity of the hydrogen storage device; The grid-connected green hydrogen plant maintains a balance between hydrogen supply and demand at different times. ， in, Indicates time period The demand for hydrogen.

16. The method as described in claim 10, characterized in that: The operational constraints of battery energy storage systems include state of charge constraints, state of charge / discharge update constraints, and battery energy storage system configuration constraints. Among them, battery energy storage systems during time periods The state of charge is satisfied. ， in, Indicates time period The state of charge, and These represent the upper and lower limits of the charged state, respectively; After considering the charging and discharging efficiency and self-loss of the battery energy storage system, the time period The state of charge is represented as, ， In the formula, This represents the self-loss coefficient of the battery energy storage system. This indicates the charge and discharge efficiency of the battery energy storage system. Indicates time period The power of the battery energy storage system, Indicates the rated capacity of the battery energy storage system; where, when When the battery is charging, it indicates that the battery energy storage system is in a charging state; when When this time, it indicates that the battery energy storage system is in a discharging state.

17. The method as described in claim 10, characterized in that: Establish grid access constraints, including, Assume the green hydrogen plant connected to the grid is connected to the busbar as follows: Then the time period The total power obtained by the grid-connected green hydrogen plant from the power grid is sufficient. ， in, Indicates time period The total power obtained by the grid-connected green hydrogen plant from the power grid, Indicates time period Downstream access bus Maximum available power at the location; Among them, total power Represented as, ， in, , and They represent time periods respectively. The power of the PEM electrolyzer, the power of the compressor, and the power of the battery energy storage system; Busbar Maximum available power at the location It is obtained by weighted averaging of the maximum available power at the access point under each renewable energy combination state, and is expressed as follows: ， in, Indicates time period Next combination state The probability, Represents the combination state Next period The maximum available power of the access point, This represents the number of discrete states for solar irradiance and wind speed within a given time period. When a grid-connected green hydrogen plant is required to produce pure green hydrogen using only renewable energy, the maximum available power at the access point is further satisfied. ， in, and Representing the combination states respectively Time period Next The first photovoltaic power station and the first Available power of a wind farm and These represent the number of photovoltaic power plants and wind farms, respectively. Represents a sufficiently large positive number. This represents a Boolean variable; when the production of pure green hydrogen is required, ;otherwise, .

18. The system as claimed in claim 10, characterized in that: The model solving module solves the optimization planning model to obtain the optimal configuration result that meets the requirements for safe operation, including: The optimal configuration result includes at least the optimal values ​​of the internal parameters of the PEM electrolyzer, the capacity configuration results of each device, and the corresponding economic evaluation results.

19. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor; characterized in that: When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 9.

20. A computer-readable storage medium storing a computer program; characterized in that: When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 9.

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