An independent micro-grid electricity-hydrogen energy storage planning method considering energy supply reliability

Abstract

This invention proposes a planning method for electric-hydrogen energy storage in independent microgrids that considers power supply reliability. Belonging to the field of optimal configuration of energy storage systems in independent microgrids, the method first constructs an objective function to minimize the total system cost, encompassing the configuration cost of electric-hydrogen energy storage, the cost of load shedding, and the cost of wind and solar curtailment. Second, it establishes constraints considering power supply reliability, including load shedding constraints, wind and solar curtailment constraints, and system operation characteristic constraints. Finally, the established planning model is equivalent to a two-layer optimization model: the upper planning layer optimizes the electric-hydrogen energy storage configuration capacity, and the lower operation layer simulates the operation and scheduling of the independent microgrid. The upper layer transfers the configured capacity to the lower layer, and the lower layer feeds back the load shedding and wind and solar curtailment data obtained from the operation simulation to the upper layer, ultimately obtaining the electric-hydrogen energy storage configuration strategy. The method proposed in this invention can effectively meet the power supply reliability requirements of independent microgrids.

Description

Technical Field

[0001] This invention relates to the field of optimized configuration of independent microgrid energy storage systems, and specifically to an independent microgrid electric-hydrogen energy storage planning method that takes into account energy supply reliability. Background Technology

[0002] Reliable power supply in remote areas is a major challenge for power grids, with the core issues being high economic costs and complex technical difficulties. Independent microgrid technology offers an effective solution to this problem, and the development of microgrids tailored to local conditions has become a current research hotspot. However, existing independent microgrids still have shortcomings in terms of reliable power supply: their core wind and solar power sources are characterized by fluctuations, intermittency, and uncertainty, making it difficult to continuously guarantee power supply. This can easily lead to power outages lasting for hours or even days, significantly reducing the quality of electricity for users and causing inconvenience to economic development and people's livelihoods.

[0003] To improve the reliability and user satisfaction of independent microgrids, existing technologies generally employ electrochemical energy storage to enhance power supply stability. Unlike existing research, this invention innovatively introduces hydrogen energy storage into the electrochemical energy storage framework. Hydrogen energy not only possesses environmentally friendly characteristics but also exhibits lower energy loss compared to electrochemical storage and can store energy for extended periods. When wind and solar power are unavailable and electrochemical energy storage is depleted, hydrogen energy can effectively support the operation of the microgrid system, thereby significantly improving power supply reliability. Summary of the Invention

[0004] The purpose of this invention is to provide an independent microgrid electricity-hydrogen energy storage planning method that takes into account the reliability of power supply. This method ensures a reliable power supply to the independent microgrid system during periods of wind and solar resource scarcity and efficiently stores surplus energy during periods of abundant wind and solar resources, thereby enabling cross-period energy dispatch and systematically improving the power supply reliability of the independent microgrid.

[0005] To achieve the above objectives, the present invention employs the following technical solutions.

[0006] A method for planning electricity-hydrogen energy storage in independent microgrids that takes into account power supply reliability includes the following steps:

[0007] S1. Construct an objective function that minimizes the total system cost;

[0008] S2. Establish a set of system operation constraints, including:

[0009] Power balance constraints: Ensure real-time balance between wind and solar power output, electric-hydrogen energy storage charging and discharging, fuel cell power generation, electrolyzer hydrogen production and load demand;

[0010] Load shedding constraints: Limiting the upper limit of load shedding power in each time period and the upper limit of total annual load shedding;

[0011] Curtailment of wind and solar power: Limiting the annual curtailment rate of wind and solar power;

[0012] Equipment characteristic constraints: covering fuel cell efficiency model, electrolyzer hydrogen production rate model, energy storage charge and discharge state model, and hydrogen storage capacity limit model;

[0013] S3. Solve using a two-layer optimization framework:

[0014] Planning level: Optimize the rated capacity of electric energy storage, the rated storage capacity of hydrogen energy storage, the rated power of fuel cells, and the rated power of electrolyzers;

[0015] Operation layer: Based on the given load demand, wind and solar power output time series data, and capacity parameters transmitted by the planning layer, simulate the annual time-period operation strategy, and feed back the load loss and wind and solar curtailment to the planning layer.

[0016] The capacity parameters are iteratively updated using a heuristic algorithm until the convergence condition is met, and the optimal electric-hydrogen energy storage configuration is output.

[0017] Furthermore, the total cost mentioned in step S1 Including equipment configuration costs and system operating costs :

[0018] .

[0019] Furthermore, the net present value (NPV) method is used to equate the annual operating cost of the independent microgrid to the system operating cost over the entire planning period. The NPV method for calculating the system operating cost is as follows:

[0020]

[0021]

[0022] in, This represents the annual operating cost of an independent microgrid. Indicates the capital recovery factor. Indicates the annual interest rate. Indicates the planning period. Indicates the simulation period throughout the year. Represents the net present value of operating costs. , These represent the unit cost of load shedding and the unit cost of wind and solar power curtailment, respectively. , They represent Unit power loss and unit power curtailment at any given time.

[0023] Furthermore, equipment configuration costs The calculation method is as follows:

[0024]

[0025]

[0026] in, , , , These represent the unit power cost of electrical energy storage, the unit power cost of hydrogen energy storage, the unit power cost of fuel cells, and the unit power cost of electrolyzers, respectively. , , , These represent the rated power of electrical energy storage, the rated storage mass of hydrogen energy storage, the rated power of fuel cells, and the rated power of electrolyzers, respectively. Indicates the rated capacity of the energy storage. This indicates the energy-to-power ratio of electrical energy storage.

[0027] Furthermore, the constraint condition for the power balance constraint mentioned in step S2 is as follows:

[0028]

[0029] in, , These represent the predicted wind and solar power and the power of wind and solar power that has been curtailed, respectively. , These represent the discharge power and charging power of the energy storage, respectively. This indicates the mass flow rate of hydrogen entering the fuel cell. Indicates fuel cell efficiency. This indicates the high calorific value of hydrogen. , These represent the power consumed by the electrical load and the power lost due to load, respectively. This indicates the power consumed by the electrolytic cell.

[0030] Furthermore, the constraint condition for the unload constraint in step S2 is as follows:

[0031]

[0032]

[0033] in, This indicates the maximum load loss during each time period. This indicates the allowable operating load loss for the entire year. This indicates the simulation period throughout the year.

[0034] Furthermore, the constraint conditions for wind and solar power curtailment in step S2 are as follows:

[0035]

[0036]

[0037] in, This represents the maximum wind and solar curtailment rate during the entire year.

[0038] Furthermore, the equipment characteristic constraints mentioned in step S2 include fuel cell characteristic constraints, electrolyzer characteristic constraints, electrical energy storage characteristic constraints, and hydrogen energy storage characteristic constraints:

[0039] (1) Constraints on fuel cell characteristics

[0040] Fuel cells can be connected in series and parallel to obtain larger fuel cells. The fuel cell voltage is calculated as follows:

[0041]

[0042] in, Indicates the DC voltage of the fuel cell. Indicates the temperature of the fuel cell. , , These represent the pressure of hydrogen gas, the pressure of oxygen gas, and standard atmospheric pressure, respectively. This indicates the voltage fluctuation characteristics caused by the dynamic properties of hydrogen and oxygen.

[0043]

[0044] in, This is a constant term (its value is constant for a given fuel cell). Indicates the magnitude of the fuel cell current. This indicates the time delay between hydrogen and oxygen. Indicates the convolution operation;

[0045] The output power of the fuel cell is:

[0046]

[0047] in, For the number of fuel cells;

[0048] The method for calculating fuel cell efficiency is as follows:

[0049]

[0050] in, This indicates the high calorific value of hydrogen. This indicates the mass flow rate of hydrogen entering the fuel cell;

[0051] The output power limitations of fuel cells are as follows:

[0052] ;

[0053] (2) Electrolytic cell characteristic constraints

[0054] The hydrogen production rate of an electrolyzer is related to its power consumption in the following way:

[0055]

[0056]

[0057]

[0058] in, Indicates the hydrogen production rate of the electrolyzer. Indicates the efficiency of the electrolytic cell. This indicates the current density in the electrolytic cell. Indicates the voltage of the electrolytic cell. Denotes Faraday's constant;

[0059] The method for calculating the voltage of an electrolytic cell is as follows:

[0060]

[0061] in, This indicates the actual voltage of the electrolytic cell. , , , , The applied voltage, reversible voltage, activation voltage, gas propagation voltage, and ohmic voltage caused by the polymer film resistance of the electrolytic cell are respectively considered.

[0062] The voltage across the battery under zero current conditions is calculated as follows:

[0063]

[0064] in, Indicates the open-circuit battery voltage. Represents the gas constant. Indicates gas temperature. Indicates oxygen pressure. This indicates the water activity, which is 1 when water is a liquid.

[0065] The voltage fluctuations caused by the electrochemical characteristics of the electrolyzer are represented by the activation voltage as follows:

[0066]

[0067] in, This represents the charge transfer coefficient used to describe the kinetics of electrochemical reactions. Indicates the current in the electrolytic cell. This indicates the current in the electrolytic cell when the voltage drop is significant.

[0068] The gas propagation voltage is shown below:

[0069]

[0070] in, Represents the coefficient of the constant term. Indicates the current limit for maximum gas propagation;

[0071] The ohmic voltage drop caused by the resistance of the proton exchange membrane is shown below:

[0072]

[0073] in, , , These represent the thickness of the proton exchange membrane, the cross-sectional area of ​​the proton exchange membrane, and the hydration ratio, respectively.

[0074] (3) Constraints on energy storage characteristics

[0075] Energy storage constraints mainly include charge / discharge power constraints, charge / discharge flag constraints, and remaining energy change constraints. The charge / discharge power constraints for energy storage are as follows:

[0076]

[0077]

[0078]

[0079] in, , They represent Discharge and charge flags at specific times. , These represent the lower and upper limits of energy storage for battery operation, respectively. Indicates the remaining energy in electrical energy storage. , These represent the discharge efficiency and charging efficiency of the energy storage, respectively.

[0080] The constraints on the change in residual energy are as follows:

[0081]

[0082] in, This indicates the self-loss rate of the energy storage device. , These represent the discharge power and charging power of the energy storage, respectively.

[0083] The charging / discharging flag constraints are as follows:

[0084] ;

[0085] (4) Constraints on hydrogen energy storage characteristics

[0086] The changes in hydrogen energy storage are as follows:

[0087]

[0088] in, The remaining hydrogen for hydrogen energy storage This indicates the mass flow rate of hydrogen entering the fuel cell;

[0089] Because hydrogen energy storage is subject to certain pressure limitations, there are certain constraints on hydrogen energy storage:

[0090]

[0091] in, This indicates the rated storage capacity of hydrogen energy storage.

[0092] Furthermore, the method for runtime layer simulation evaluation in step S3 is as follows:

[0093] When the net load is >0, depending on the power shortage situation, the three operations of energy storage discharge, fuel cell power generation and load shedding are sequentially invoked.

[0094] When the net load is less than 0, the three operations of charging the electric storage, producing hydrogen from the electrolyzer, and executing the curtailment of wind and solar power will be called in sequence according to the power surplus situation.

[0095] When net load = 0, no equipment needs to operate.

[0096] Furthermore, step S3 involves iteratively updating the capacity parameter using a heuristic algorithm until the convergence condition is met, including the following steps:

[0097] The planning layer calculates the fitness value of each individual based on the objective function, and ranks the individuals accordingly.

[0098] Subsequently, a new generation of individuals is generated according to the rules of the selected heuristic algorithm;

[0099] Check if the termination condition has been met; if so, output the current best individual.

[0100] The termination condition is reaching the preset maximum number of iterations, or the fitness value of the optimal individual not changing in a number of consecutive iterations.

[0101] The advantages of this invention are:

[0102] By coordinating the configuration of electric energy storage and hydrogen energy storage systems, the reliability of independent microgrid power supply and overall power quality can be improved through energy complementarity. Utilizing the extremely low self-loss characteristics of hydrogen energy storage, it can serve as a backup energy source for electrochemical energy storage when wind and solar resources are continuously scarce, thus avoiding power outages caused by the depletion of energy storage. Key reliability indicators such as load shedding and wind and solar curtailment are incorporated into system constraints to ensure that the planning scheme meets the requirements for high power supply reliability. Through the coordinated scheduling of electrochemical energy storage and hydrogen energy storage, a cross-time period energy relay can be formed.

[0103] With the goal of minimizing the sum of configuration and operating costs of the electric-hydrogen energy storage system, we take into account both equipment investment costs and operating penalty costs, optimize the best ratio of electric energy storage and hydrogen energy storage, avoid capacity waste caused by a single energy storage technology, and minimize the total system cost.

[0104] Accurately model the operational characteristic constraints of fuel cells, electrolyzers, electrical energy storage, and hydrogen energy storage, and improve the accuracy of operational simulation through refined equipment models;

[0105] A two-layer optimization framework (upper planning layer and lower execution layer) is adopted, and heuristic algorithms are applied to solve the problem, which effectively reduces the difficulty of solving complex models. Attached Figure Description

[0106] Figure 1 This is a schematic diagram of the independent microgrid electric-hydrogen energy storage planning method that takes into account the reliability of energy supply according to the present invention. Detailed Implementation

[0107] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0108] A planning method for electricity-hydrogen energy storage in independent microgrids that takes into account power supply reliability is provided. Please refer to [reference needed]. Figure 1 By using input data such as electricity load, wind power output, photovoltaic power output, planning period, annual interest rate, and unit cost of energy storage, a two-layer optimization framework is adopted to output the optimal electric-hydrogen energy storage configuration scheme.

[0109] Specifically, it includes the following steps:

[0110] S1. Construct an objective function that minimizes the total system cost. Including equipment configuration costs and system operating costs :

[0111] .

[0112] Equipment configuration costs are calculated over the entire planning period, while system operating costs are calculated only on an annual basis. Therefore, these two types of costs differ. The net present value (NPV) method is used to equate operating costs to operating costs over the entire planning period. The NPV calculation method is as follows:

[0113]

[0114]

[0115] in, This represents the annual operating cost of an independent microgrid. Indicates the capital recovery factor. Indicates the annual interest rate. Indicates the planning period. Indicates the simulation period throughout the year. Represents the net present value of operating costs. , These represent the unit cost of load shedding and the unit cost of wind and solar power curtailment, respectively. , They represent Unit power loss and unit power curtailment at any given time.

[0116] Equipment configuration cost The calculation method is as follows:

[0117]

[0118]

[0119] in, , , , These represent the unit power cost of electrical energy storage, the unit power cost of hydrogen energy storage, the unit power cost of fuel cells, and the unit power cost of electrolyzers, respectively. , , , These represent the rated power of electrical energy storage, the rated storage mass of hydrogen energy storage, the rated power of fuel cells, and the rated power of electrolyzers, respectively. Indicates the rated capacity of the energy storage. This indicates the energy-to-power ratio of electrical energy storage.

[0120] S2. Construct various constraints related to system operation: The main constraints of independent microgrid system operation include power balance constraints, load shedding constraints, wind and solar curtailment constraints, fuel cell characteristic constraints, electrolyzer characteristic constraints, electrical energy storage characteristic constraints, and hydrogen energy storage characteristic constraints.

[0121] S21. System-level operational constraints: including power balance constraints, load shedding constraints, and wind and solar curtailment constraints, etc.

[0122] S211. Power balance constraint: To ensure reliable power supply to independent microgrid users, power balance must be maintained in real time. The system power balance constraint conditions are as follows:

[0123]

[0124] in, , These represent the predicted wind and solar power and the power of wind and solar power that has been curtailed, respectively. , These represent the discharge power and charging power of the energy storage, respectively. This indicates the mass flow rate of hydrogen entering the fuel cell. Indicates fuel cell efficiency. This indicates the high calorific value of hydrogen. , These represent the power consumed by the electrical load and the power lost due to load, respectively. This indicates the power consumed by the electrolytic cell.

[0125] S212. Load loss constraint: The amount of load loss and the total amount of load loss at each moment should be subject to certain limitations.

[0126]

[0127]

[0128] in, This indicates the maximum load loss during each time period. This indicates the allowable operating load loss for the entire year. This represents the simulation period throughout the year. By setting the allowable load shedding and total load shedding for each period, the permissible reliability of the independent microgrid is ensured, significantly improving the operational reliability of the independent microgrid.

[0129] S213. Curtailment of wind and solar power: To avoid wasting wind and solar resources, the amount of wind and solar power curtailed must be limited.

[0130]

[0131]

[0132] in, This represents the maximum wind and solar curtailment rate during the entire year.

[0133] S22. Equipment-level characteristic constraints: These include equipment-related constraints such as fuel cell characteristic constraints, electrolyzer characteristic constraints, electrical energy storage characteristic constraints, and hydrogen energy storage characteristic constraints.

[0134] S221. Constraints on Fuel Cell Characteristics: Fuel cells can convert the chemical energy of the combination of oxygen and hydrogen into electrical energy. Proton exchange membrane fuel cells are extremely common. Taking proton exchange membrane fuel cells as an example, we will analyze the operating characteristics of fuel cells.

[0135] Fuel cells can be connected in series and parallel to obtain larger fuel cells. The fuel cell voltage is calculated as follows:

[0136]

[0137] in, Indicates the DC voltage of the fuel cell. Indicates the temperature of the fuel cell. , , These represent the pressure of hydrogen gas, the pressure of oxygen gas, and standard atmospheric pressure, respectively. This indicates the voltage fluctuation characteristics caused by the dynamic properties of hydrogen and oxygen.

[0138]

[0139] in, This is a constant term (its value is constant for a given fuel cell). Indicates the magnitude of the fuel cell current. This indicates the time delay between hydrogen and oxygen. Indicates the convolution operation;

[0140] The output power of the fuel cell is:

[0141]

[0142] in, For the number of fuel cells;

[0143] The method for calculating fuel cell efficiency is as follows:

[0144]

[0145] in, This indicates the high calorific value of hydrogen. This indicates the mass flow rate of hydrogen entering the fuel cell;

[0146] The output power limitations of fuel cells are as follows:

[0147] .

[0148] S222. Electrolyzer Characteristics Constraints: The electrolyzer can utilize surplus electrical energy to decompose water and produce hydrogen and oxygen. The produced hydrogen can be stored and converted back into electrical energy via fuel cells during power shortages.

[0149] The hydrogen production rate of an electrolyzer is related to its power consumption in the following way:

[0150]

[0151]

[0152]

[0153] in, Indicates the hydrogen production rate of the electrolyzer. Indicates the efficiency of the electrolytic cell. This indicates the current density in the electrolytic cell. Indicates the voltage of the electrolytic cell. Denotes Faraday's constant;

[0154] The method for calculating the voltage of an electrolytic cell is as follows:

[0155]

[0156] in, This indicates the actual voltage of the electrolytic cell. , , , , The applied voltage, reversible voltage, activation voltage, gas propagation voltage, and ohmic voltage caused by the polymer film resistance of the electrolytic cell are respectively considered.

[0157] The voltage across the battery under zero current conditions is calculated as follows:

[0158]

[0159] in, Indicates the open-circuit battery voltage. Represents the gas constant. Indicates gas temperature. Indicates oxygen pressure. This indicates the water activity, which is 1 when water is a liquid.

[0160] The voltage fluctuations caused by the electrochemical characteristics of the electrolyzer are represented by the activation voltage as follows:

[0161]

[0162] in, This represents the charge transfer coefficient used to describe the kinetics of electrochemical reactions. Indicates the current in the electrolytic cell. This indicates the current in the electrolytic cell when the voltage drop is significant.

[0163] The gas propagation voltage is shown below:

[0164]

[0165] in, Represents the coefficient of the constant term. Indicates the current limit for maximum gas propagation;

[0166] The ohmic voltage drop caused by the resistance of the proton exchange membrane is shown below:

[0167]

[0168] in, , , These represent the thickness of the proton exchange membrane, the cross-sectional area of ​​the proton exchange membrane, and the hydration ratio, respectively.

[0169] S223. Constraints on energy storage characteristics, mainly including constraints on charging and discharging power, constraints on charging and discharging flags, constraints on changes in remaining energy, and other related constraints.

[0170] The power constraints for charging and discharging of electrical storage are as follows:

[0171]

[0172]

[0173]

[0174] in, , They represent Discharge and charge flags at specific times. , These represent the lower and upper limits of energy storage for battery operation, respectively. Indicates the remaining energy in electrical energy storage. , These represent the energy storage discharge efficiency and charging efficiency, respectively.

[0175] The constraints on the change in residual energy are as follows:

[0176]

[0177] in, This indicates the self-loss rate of the energy storage device.

[0178] The charging / discharging flag constraints are as follows:

[0179] .

[0180] S224. Constraints on hydrogen energy storage characteristics: The hydrogen energy storage characteristics are determined by the hydrogen consumption of the fuel cell and the hydrogen production of the electrolyzer.

[0181] The changes in hydrogen energy storage are as follows:

[0182]

[0183] in, The remaining hydrogen for hydrogen energy storage.

[0184] Because hydrogen energy storage is subject to certain pressure limitations, there are certain constraints on hydrogen energy storage:

[0185] .

[0186] S3. A two-layer optimization framework is used for solving the model: To facilitate model solving, the model is divided into a planning layer and an operation layer. The planning layer includes an objective function with the goal of minimizing the total cost, while the operation layer includes various constraints related to system operation.

[0187] S31, Planning Layer (Capacity Optimization): Select a heuristic algorithm (such as genetic algorithm, particle swarm optimization, etc.) to randomly initialize a set of individuals. Each individual contains planning variables such as electrical energy storage capacity, hydrogen energy storage capacity, fuel cell rated power, and electrolyzer rated power. The generated capacity combinations are then passed to the operation layer for simulation evaluation.

[0188] S32. Operational Layer (Simulation Evaluation): Based on given load demand, wind and solar power output time-series data, and equipment capacity parameters transmitted from the planning layer, conduct year-round time-period operational simulations. The simulation method is as follows: First, calculate the net load, which is the current time-period load demand minus wind and solar power output, to obtain the net load value. Simulation evaluation is conducted based on the following conditions:

[0189] If the net load is greater than 0, indicating a power shortage, the system will prioritize discharging the stored energy to meet the net load. If there is still a power gap after the stored energy is discharged, the fuel cell will be activated to supplement the power. If the fuel cell still cannot meet all the demand, the system will perform a load shedding operation.

[0190] Net load < 0, i.e., surplus power: prioritize using surplus power to charge the electric energy storage; if there is still surplus power after reaching the maximum charging power or after the electric energy storage is fully charged, start the electrolyzer to produce hydrogen; if there is still surplus power after the electrolyzer is running at full power or the hydrogen storage equipment has reached the maximum allowable storage capacity, discard that part of the wind and solar power.

[0191] S33. Result Feedback and Individual Update: After the simulation is completed, the cumulative annual load shedding and wind / solar curtailment are calculated and uploaded to the planning layer. The planning layer calculates the fitness value of each individual based on the total cost formula, and ranks the individuals accordingly. Subsequently, a new generation of individuals is generated according to the rules of the selected heuristic algorithm (such as selection, crossover, mutation, particle position update, etc.).

[0192] S34. Termination Judgment and Output: Check whether the preset maximum number of iterations has been reached, or whether the fitness value of the optimal individual has not changed in several consecutive iterations. If either termination condition is met, output the current optimal individual; otherwise, return to step S32 to continue the simulation and iterative update.

[0193] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for planning electricity-hydrogen energy storage in an independent microgrid that takes into account power supply reliability, characterized in that, Includes the following steps: S1. Construct an objective function that minimizes the total system cost; S2. Establish a set of system operation constraints, including: Power balance constraints: Ensure real-time balance between wind and solar power output, electric-hydrogen energy storage charging and discharging, fuel cell power generation, electrolyzer hydrogen production and load demand; Load shedding constraints: Limiting the upper limit of load shedding power in each time period and the upper limit of total annual load shedding; Curtailment of wind and solar power: Limiting the annual curtailment rate of wind and solar power; Equipment characteristic constraints: covering fuel cell efficiency model, electrolyzer hydrogen production rate model, energy storage charge and discharge state model, and hydrogen storage capacity limit model; S3. Solve using a two-layer optimization framework: Planning level: Optimize the rated capacity of electric energy storage, the rated storage capacity of hydrogen energy storage, the rated power of fuel cells, and the rated power of electrolyzers; Operation layer: Based on the given load demand, wind and solar power output time series data, and capacity parameters transmitted by the planning layer, simulate the annual time-period operation strategy, and feed back the load loss and wind and solar curtailment to the planning layer. The capacity parameters are iteratively updated using a heuristic algorithm until the convergence condition is met, and the optimal electric-hydrogen energy storage configuration scheme is output. The power balance constraint conditions mentioned in step S2 are as follows: in, , These represent the predicted wind and solar power and the power of wind and solar power that has been curtailed, respectively. , These represent the discharge power and charging power of the energy storage, respectively. This indicates the mass flow rate of hydrogen entering the fuel cell. Indicates fuel cell efficiency. This indicates the high calorific value of hydrogen. , These represent the power consumed by the electrical load and the power lost due to load, respectively. This indicates the power consumption of the electrolytic cell; The constraint condition for the unload constraint in step S2 is: in, This indicates the maximum load loss during each time period. This indicates the allowable operating load loss for the entire year. This indicates the simulation period throughout the year.

2. The independent microgrid electricity-hydrogen energy storage planning method considering power supply reliability according to claim 1, characterized in that, The total cost mentioned in step S1 Including equipment configuration costs and system operating costs : 。 3. The independent microgrid electricity-hydrogen energy storage planning method considering power supply reliability according to claim 2, characterized in that, The net present value (NPV) method is used to equate the annual operating cost of the independent microgrid to the system operating cost over the entire planning period. The NPV method for calculating the system operating cost is as follows: in, This represents the annual operating cost of an independent microgrid. Indicates the capital recovery factor. Indicates the annual interest rate. Indicates the planning period. Indicates the simulation period throughout the year. Represents the net present value of operating costs. , These represent the unit cost of load shedding and the unit cost of wind and solar power curtailment, respectively. , They represent Unit power loss and unit power curtailment at any given time.

4. The independent microgrid electricity-hydrogen energy storage planning method considering power supply reliability according to claim 2, characterized in that, Equipment configuration cost The calculation method is as follows: in, , , , These represent the unit power cost of electrical energy storage, the unit power cost of hydrogen energy storage, the unit power cost of fuel cells, and the unit power cost of electrolyzers, respectively. , , , These represent the rated power of electrical energy storage, the rated storage mass of hydrogen energy storage, the rated power of fuel cells, and the rated power of electrolyzers, respectively. Indicates the rated capacity of the energy storage. This indicates the energy-to-power ratio of electrical energy storage.

5. The independent microgrid electricity-hydrogen energy storage planning method considering power supply reliability according to claim 1, characterized in that, The constraint conditions for wind and solar power curtailment mentioned in step S2 are as follows: in, This represents the maximum wind and solar curtailment rate during the entire year.

6. The independent microgrid electricity-hydrogen energy storage planning method considering power supply reliability according to claim 1, characterized in that, The equipment characteristic constraints mentioned in step S2 include fuel cell characteristic constraints, electrolyzer characteristic constraints, electrical energy storage characteristic constraints, and hydrogen energy storage characteristic constraints: (1) Constraints on fuel cell characteristics Fuel cells can be connected in series and parallel to obtain larger fuel cells. The fuel cell voltage is calculated as follows: in, Indicates the DC voltage of the fuel cell. Indicates the temperature of the fuel cell. , , These represent the pressure of hydrogen gas, the pressure of oxygen gas, and standard atmospheric pressure, respectively. This indicates the voltage fluctuation characteristics caused by the dynamic properties of hydrogen and oxygen. in, It is a constant. Indicates the magnitude of the fuel cell current. This indicates the time delay between hydrogen and oxygen. Indicates the convolution operation; The output power of the fuel cell is: in, For the number of fuel cells; The method for calculating fuel cell efficiency is as follows: in, This indicates the high calorific value of hydrogen. This indicates the mass flow rate of hydrogen entering the fuel cell; The output power limitations of fuel cells are as follows: ； (2) Electrolytic cell characteristic constraints The hydrogen production rate of an electrolyzer is related to its power consumption in the following way: in, Indicates the hydrogen production rate of the electrolyzer. Indicates the efficiency of the electrolytic cell. This indicates the current density in the electrolytic cell. Indicates the voltage of the electrolytic cell. Denotes Faraday's constant; The method for calculating the voltage of an electrolytic cell is as follows: in, This indicates the actual voltage of the electrolytic cell. , , , , The applied voltage, reversible voltage, activation voltage, gas propagation voltage, and ohmic voltage caused by the polymer film resistance of the electrolytic cell are respectively considered. The voltage across the battery under zero current conditions is calculated as follows: in, Indicates the open-circuit battery voltage. Represents the gas constant. Indicates gas temperature. Indicates oxygen pressure. Indicates water activity; The voltage fluctuations caused by the electrochemical characteristics of the electrolyzer are represented by the activation voltage as follows: in, This represents the charge transfer coefficient used to describe the kinetics of electrochemical reactions. Indicates the current in the electrolytic cell. This indicates the current in the electrolytic cell when the voltage drop is significant. The gas propagation voltage is shown below: in, Represents the coefficient of the constant term. Indicates the current limit for maximum gas propagation; The ohmic voltage drop caused by the resistance of the proton exchange membrane is shown below: in, , , These represent the thickness of the proton exchange membrane, the cross-sectional area of ​​the proton exchange membrane, and the hydration ratio, respectively. (3) Constraints on energy storage characteristics Energy storage constraints include charge / discharge power constraints, charge / discharge flag constraints, and remaining energy change constraints. The charge / discharge power constraints for energy storage are as follows: in, , They represent Discharge and charge flags at specific times. , These represent the lower and upper limits of energy storage for battery operation, respectively. Indicates the remaining energy in electrical energy storage. , These represent the discharge efficiency and charging efficiency of the energy storage, respectively. The constraints on the change in residual energy are as follows: in, This indicates the self-loss rate of the energy storage device. , These represent the discharge power and charging power of the energy storage, respectively. The charging / discharging flag constraints are as follows: ； (4) Constraints on hydrogen energy storage characteristics The changes in hydrogen energy storage are as follows: in, The remaining hydrogen for hydrogen energy storage This indicates the mass flow rate of hydrogen entering the fuel cell; Because hydrogen energy storage is subject to certain pressure limitations, there are certain constraints on hydrogen energy storage: in, This indicates the rated storage capacity of hydrogen energy storage.

7. The independent microgrid electricity-hydrogen energy storage planning method considering power supply reliability according to claim 1, characterized in that, The method for runtime layer simulation evaluation in step S3 is as follows: When the net load is >0, depending on the power shortage situation, the three operations of energy storage discharge, fuel cell power generation and load shedding are sequentially invoked. When the net load is less than 0, based on the surplus power situation, the following three operations are sequentially activated: charging of electric energy storage, hydrogen production by electrolyzer, and execution of curtailed wind and solar power.

8. The independent microgrid electricity-hydrogen energy storage planning method considering power supply reliability according to claim 1, characterized in that, Step S3 involves iteratively updating the capacity parameter using a heuristic algorithm until the convergence condition is met. This includes the following steps: The planning layer calculates the fitness value of each individual based on the objective function, and ranks the individuals accordingly. Subsequently, a new generation of individuals is generated according to the rules of the selected heuristic algorithm; Check if the termination condition has been met; if so, output the current best individual. The termination condition is reaching the preset maximum number of iterations, or the fitness value of the optimal individual not changing in a number of consecutive iterations.

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