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

Abstract

The invention provides an independent micro-grid electricity-hydrogen energy storage planning method considering energy supply reliability, and belongs to the field of independent micro-grid energy storage system optimal configuration, and the method comprises the steps: firstly constructing a target function with the minimization of the total cost of a system as a target, and covering the electricity-hydrogen energy storage configuration cost, the loss load cost and the abandoned wind and light cost; secondly, establishing constraint conditions considering energy supply reliability, including loss-of-load constraint, abandoned wind and light constraint, system operation characteristic constraint and the like; and finally, enabling the established planning model to be equivalent to a double-layer optimization model: an upper layer planning layer optimizes electricity-hydrogen energy storage configuration capacity, a lower layer operation layer simulates independent micro-grid operation scheduling, an upper layer transmits the configuration capacity to a lower layer, and the lower layer feeds back a load loss amount and a wind curtailment amount obtained by operation simulation to the upper layer. And finally obtaining an electricity-hydrogen energy storage configuration strategy. The method provided by the invention can effectively meet the energy supply reliability requirement of the independent micro-grid.

Description

Technical Field

[0001] The present invention relates to the field of optimized configuration of independent microgrid energy storage systems, and in particular to an independent microgrid electric-hydrogen energy storage planning method taking energy supply reliability into account. Background Art

[0002] Providing reliable power to remote areas is a major challenge facing the power grid. The core issues lie in 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 research hotspot. However, existing independent microgrids still lack reliable energy supply. The volatility, intermittency, and uncertainty of their core wind and solar power sources make it difficult to ensure continuous power supply, which can easily lead to power outages lasting hours or even days, significantly reducing the quality of electricity for users and causing inconvenience to economic development and people's livelihoods.

[0003] To enhance the reliability and user satisfaction of independent microgrids, existing technologies generally employ electrochemical energy storage to improve energy supply stability. Unlike existing research, this invention innovatively incorporates hydrogen energy storage, building upon electrochemical energy storage. Hydrogen energy is not only environmentally friendly but also exhibits lower losses than electrochemical energy storage, allowing for long-term energy storage. When wind and solar power sources are unable to produce power and the electrochemical energy storage is depleted, hydrogen energy can effectively support microgrid system operations, significantly improving energy supply reliability. Summary of the Invention

[0004] The purpose of the present invention is to provide an independent microgrid electric-hydrogen energy storage planning method that takes into account energy supply reliability, ensuring that the independent microgrid system can achieve reliable supply of electricity during periods of scarce wind and solar resources, and efficiently storing surplus energy during periods of abundant wind and solar resources, realizing energy scheduling across time periods, and thus systematically improving the energy supply reliability of the independent microgrid.

[0005] In order to achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions.

[0006] A method for planning an independent microgrid electricity-hydrogen energy storage system taking into account energy supply reliability includes the following steps: S1. Construct an objective function with the goal of minimizing the total cost of the system; S2. Establish a system operation constraint set, including: Power balance constraints: ensuring 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 loss constraint: limit the upper limit of load loss power in each period and the upper limit of the total annual load loss; Wind and solar curtailment constraints: set an upper limit on the annual wind and solar curtailment rate; Equipment characteristic constraints: covering fuel cell efficiency model, electrolyzer hydrogen production rate model, electric energy storage charge and discharge state model, and hydrogen energy storage reserve limit model; S3, using a two-layer optimization framework to solve: Planning layer: Optimize the rated capacity of electric energy storage, rated reserves of hydrogen energy storage, rated power of fuel cells, and rated power of electrolyzers; Operation layer: Based on the given load demand, wind and solar output time series data, and the capacity parameters transmitted by the planning layer, it simulates the operation strategy for each period of the year and feeds back the load loss and wind and solar curtailment to the planning layer; The capacity parameters are iteratively updated through a heuristic algorithm until the convergence conditions are met, and the optimal electric-hydrogen energy storage configuration solution is output.

[0007] Furthermore, the total cost in step S1 Including equipment configuration costs and system operating costs : .

[0008] Furthermore, the net present value method is used to equate the annual operating cost of the independent microgrid to the system operating cost of the entire planning period. The net present value method for calculating the system operating cost is as follows: in, represents the annual operating cost of an independent microgrid, represents the capital recovery coefficient, represents the annual interest rate, represents the planning cycle, represents the simulation period throughout the year, represents the net present value of operating costs, 、 Represent the unit cost of lost load and the unit cost of abandoned wind and solar power, 、 Respectively Unit load loss power and unit abandoned wind and solar power at each moment.

[0009] Furthermore, the equipment configuration cost The calculation method is as follows: in, 、 、 、 They represent the unit power cost of electric energy storage, hydrogen energy storage, fuel cell and electrolyzer, respectively. 、 、 、 They represent the rated power of electric 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. Indicates the energy-to-power ratio of electrical energy storage.

[0010] Furthermore, the power balance constraint in step S2 is: in, 、 They represent the predicted wind and solar power and the abandoned wind and solar power respectively. 、 Respectively represent the energy storage discharge power and charging power, represents the mass flow rate of hydrogen flowing into the fuel cell, represents the fuel cell efficiency, Indicates the high calorific value of hydrogen, 、 Respectively represent the power consumed by the electric load and the power lost by the load, Indicates the power consumption of the electrolytic cell.

[0011] Furthermore, the load loss constraint in step S2 is: in, Indicates the maximum load loss during each period of operation. Indicates the amount of load loss allowed throughout the year. Indicates the simulation period throughout the year.

[0012] Furthermore, the constraints for curtailing wind and solar power in step S2 are: in, It is the maximum wind and solar power curtailment rate throughout the year.

[0013] Furthermore, the equipment characteristic constraints in step S2 include fuel cell characteristic constraints, electrolyzer characteristic constraints, electrical energy storage characteristic constraints, and hydrogen energy storage characteristic constraints: (1) Fuel cell characteristic constraints Fuel cells are connected in series and parallel to obtain a larger fuel cell. The fuel cell voltage is calculated as follows: in, represents the DC voltage of the fuel cell, represents the fuel cell temperature, 、 、 Represent hydrogen pressure, oxygen pressure and standard atmospheric pressure respectively. Indicates the voltage fluctuation characteristics due to the dynamic characteristics of hydrogen and oxygen; in, is a constant term (for a certain fuel cell, its value is a constant), Indicates the fuel cell current size, Indicates the time delay between hydrogen and oxygen, Represents the convolution operation; The fuel cell output power is: in, is the number of fuel cells; The fuel cell efficiency calculation method is: in, Indicates the high calorific value of hydrogen, Represents the mass flow rate of hydrogen flowing into the fuel cell; The fuel cell output power limits are as follows: ; (2) Electrolytic cell characteristic constraints The relationship between the hydrogen production rate and power consumption of the electrolyzer is as follows: in, represents the hydrogen production rate of the electrolyzer, represents the electrolyzer efficiency, represents the electrolytic cell current density, represents the electrolytic cell voltage, represents the Faraday constant; The calculation method of electrolytic cell voltage is: in, Indicates the actual voltage of the electrolytic cell, 、 、 、 、 The ohmic voltage caused by the electrolytic cell external voltage, reversible voltage, activation voltage, gas propagation voltage and polymer membrane resistance respectively; The voltage across the battery under zero current conditions is calculated as follows: in, represents the open circuit battery voltage, represents the gas constant, represents the gas temperature, Indicates oxygen pressure, represents water activity, which takes the value of 1 when water is liquid; The voltage fluctuation caused by the electrochemical characteristics of the electrolyzer is expressed by the activation voltage as follows: in, represents the charge transfer coefficient used to describe the electrochemical reaction kinetics, represents the electrolytic cell current, Indicates the electrolytic cell current when the voltage drop is significant; The gas propagation voltage is given by: in, represents the constant term coefficient, represents the current limit for maximum gas propagation; The ohmic voltage drop due to the PEM resistance is shown below: in, 、 、 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 electrical energy storage characteristics Energy storage constraints mainly include charge and discharge power constraints, charge and discharge identification constraints, and remaining energy change constraints. The energy storage charge and discharge power constraints are as follows: in, 、 Respectively The discharge flag and charge flag at the moment, 、 They represent the lower and upper limits of the battery's energy storage capacity. Indicates the remaining energy of the electric energy storage. 、 Respectively represent the discharge efficiency and charging efficiency of electric energy storage; The remaining energy change constraint is as follows: in, Represents the self-consumption rate of the electric energy storage device, 、 Respectively represent the discharge power and charging power of the energy storage; The charge and discharge flags are constrained as follows: ; (4) Constraints of hydrogen energy storage characteristics The changes in hydrogen energy storage are as follows: in, The remaining hydrogen for hydrogen energy storage, Represents the mass flow rate of hydrogen flowing into the fuel cell; Since hydrogen energy storage pressure is subject to certain restrictions, hydrogen energy storage has certain constraints: in, Indicates the rated storage mass of hydrogen energy storage.

[0014] Furthermore, the method for running layer simulation evaluation in step S3 is: When the net load is greater than 0, the system will sequentially call for energy storage discharge, fuel cell power generation, and load shedding according to the power shortage situation; When the net load is less than 0, the system will sequentially call upon energy storage charging, electrolyzer hydrogen production, and curtailment of wind and solar power, depending on the power surplus. When the net load = 0, no device needs to take any action.

[0015] Furthermore, in step S3, iteratively updating the capacity parameter by a heuristic algorithm until the convergence condition is met 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 whether the termination condition is met, and if so, output the current optimal individual; The termination condition is that the preset maximum number of iterations is reached, or the fitness value of the optimal individual does not change in several consecutive iterations.

[0016] The advantages of the present invention are: Coordinated configuration of electric and hydrogen energy storage systems improves the reliability and overall power quality of independent microgrids through energy complementarity. Utilizing the extremely low self-consumption characteristics of hydrogen energy storage, it serves as a backup energy source for electrochemical energy storage when wind and solar resources are continuously scarce, avoiding power outages caused by energy storage depletion. Key reliability indicators such as load loss and abandoned wind and solar power are incorporated into system constraints to ensure that the planning scheme meets high energy supply reliability requirements. Through the coordinated scheduling of electrochemical and hydrogen energy storage, a cross-time energy relay is formed. Taking the minimization of the sum of the configuration cost and operating cost of the electric-hydrogen energy storage system as the optimization goal, the equipment investment cost and operating penalty cost are coordinated to optimize the optimal 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; Accurately model the operational characteristics and constraints of fuel cells, electrolyzers, electric energy storage, and hydrogen energy storage, and improve the accuracy of operational simulations through refined equipment models; A two-layer optimization framework (upper planning layer and lower operation layer) is adopted, and a heuristic algorithm is applied to solve the problem, which effectively reduces the difficulty of solving complex models. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the independent microgrid electricity-hydrogen energy storage planning method taking into account energy supply reliability of the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0019] A method for planning independent microgrid electricity-hydrogen energy storage considering energy supply reliability, please refer to Figure 1 , by inputting data such as electric load, wind power output, photovoltaic 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 plan.

[0020] Specifically, the method includes the following steps: S1. Construct an objective function with the goal of minimizing the total cost of the system. Including equipment configuration costs and system operating costs : .

[0021] The equipment configuration cost is for the entire planning cycle, while the system operating cost is calculated only on an annual basis. Due to the difference between the two types of costs, the net present value method is used to equate the operating cost with the operating cost of the entire planning cycle. The net present value calculation method is as follows: in, represents the annual operating cost of an independent microgrid, represents the capital recovery coefficient, represents the annual interest rate, represents the planning cycle, represents the simulation period throughout the year, represents the net present value of operating costs, 、 Represent the unit cost of lost load and the unit cost of abandoned wind and solar power, 、 Respectively Unit load loss power and unit abandoned wind and solar power at each moment.

[0022] Equipment configuration cost The calculation method is as follows: in, 、 、 、 They represent the unit power cost of electric energy storage, hydrogen energy storage, fuel cell and electrolyzer, respectively. 、 、 、 They represent the rated power of electric 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. Indicates the energy-to-power ratio of electrical energy storage.

[0023] S2. Construct various constraints related to system operation: The operating constraints of the independent microgrid system mainly include power balance constraints, load loss constraints, wind and solar power curtailment constraints, fuel cell characteristic constraints, electrolyzer characteristic constraints, electric energy storage characteristic constraints and hydrogen energy storage characteristic constraints.

[0024] S21. System-level operational constraints: including power balance constraints, load loss constraints, wind and solar curtailment constraints and other related constraints.

[0025] S211, power balance constraint, in order to ensure reliable energy supply to independent microgrid users, power balance must be achieved at all times. The system power balance constraint conditions are as follows: in, 、 They represent the predicted wind and solar power and the abandoned wind and solar power respectively. 、 Respectively represent the energy storage discharge power and charging power, represents the mass flow rate of hydrogen flowing into the fuel cell, represents the fuel cell efficiency, Indicates the high calorific value of hydrogen, 、 Respectively represent the power consumed by the electric load and the power lost by the load, Indicates the power consumption of the electrolytic cell.

[0026] S212. Load loss constraints: The amount of load loss at each moment and the total amount of load loss should be subject to certain restrictions: in, Indicates the maximum load loss during each period of operation. Indicates the amount of load loss allowed throughout the year. Indicates the simulation period throughout the year. By setting the allowable load loss and total load loss in each period, the reliability of the independent microgrid is guaranteed and the operational reliability of the independent microgrid is greatly improved.

[0027] S213, Wind and Solar Curtailment Constraints: To avoid wasting wind and solar resources, the amount of wind and solar curtailment must be limited: in, It is the maximum wind and solar power curtailment rate throughout the year.

[0028] S22. Equipment-level characteristic constraints: include equipment-related constraints such as fuel cell characteristic constraints, electrolyzer characteristic constraints, electrical energy storage characteristic constraints, and hydrogen energy storage characteristic constraints.

[0029] S221. Fuel cell characteristic constraints: 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. The fuel cell operating characteristics are analyzed using proton exchange membrane fuel cells as an example.

[0030] Fuel cells are connected in series and parallel to obtain a larger fuel cell. The fuel cell voltage is calculated as follows: in, represents the DC voltage of the fuel cell, represents the fuel cell temperature, 、 、 Represent hydrogen pressure, oxygen pressure and standard atmospheric pressure respectively. Indicates the voltage fluctuation characteristics due to the dynamic characteristics of hydrogen and oxygen; in, is a constant term (for a certain fuel cell, its value is a constant), Indicates the fuel cell current size, Indicates the time delay between hydrogen and oxygen, Represents the convolution operation; The fuel cell output power is: in, is the number of fuel cells; The fuel cell efficiency calculation method is: in, Indicates the high calorific value of hydrogen, Represents the mass flow rate of hydrogen flowing into the fuel cell; The fuel cell output power limits are as follows: .

[0031] S222. Electrolyzer Characteristics Constraints: Electrolyzers can use excess electricity to decompose water to produce hydrogen and oxygen. The hydrogen produced can be stored and converted back into electricity through fuel cells during power shortages.

[0032] The relationship between the hydrogen production rate and power consumption of the electrolyzer is as follows: in, represents the hydrogen production rate of the electrolyzer, represents the electrolyzer efficiency, represents the electrolytic cell current density, represents the electrolytic cell voltage, represents the Faraday constant; The calculation method of electrolytic cell voltage is: in, Indicates the actual voltage of the electrolytic cell, 、 、 、 、 The ohmic voltage caused by the electrolytic cell external voltage, reversible voltage, activation voltage, gas propagation voltage and polymer membrane resistance respectively; The voltage across the battery under zero current conditions is calculated as follows: in, represents the open circuit battery voltage, represents the gas constant, represents the gas temperature, Indicates oxygen pressure, represents water activity, which takes the value of 1 when water is liquid; The voltage fluctuation caused by the electrochemical characteristics of the electrolyzer is expressed by the activation voltage as follows: in, represents the charge transfer coefficient used to describe the electrochemical reaction kinetics, represents the electrolytic cell current, Indicates the electrolytic cell current when the voltage drop is significant; The gas propagation voltage is given by: in, represents the constant term coefficient, represents the current limit for maximum gas propagation; The ohmic voltage drop due to the PEM resistance is shown below: in, 、 、 represent the thickness of the proton exchange membrane, the cross-sectional area of ​​the proton exchange membrane, and the hydration ratio, respectively.

[0033] S223, electric energy storage characteristic constraints, mainly include charge and discharge power constraints, charge and discharge identification constraints, remaining energy change constraints and other related constraints.

[0034] The charging and discharging power constraints of electric energy storage are as follows: in, 、 Respectively The discharge flag and charge flag at the moment, 、 They represent the lower and upper limits of the battery's energy storage capacity. Indicates the remaining energy of the electric energy storage. 、 They represent the discharge efficiency and charging efficiency of energy storage respectively.

[0035] The remaining energy change constraint is as follows: in, Indicates the self-consumption rate of the electric energy storage device.

[0036] The charge and discharge flags are constrained as follows: .

[0037] S224. Constraints on hydrogen energy storage characteristics: Hydrogen energy storage characteristics are determined by the hydrogen consumption of the fuel cell and the hydrogen production of the electrolyzer.

[0038] The changes in hydrogen energy storage are as follows: in, The remaining hydrogen amount for hydrogen energy storage.

[0039] Since hydrogen energy storage pressure is subject to certain restrictions, hydrogen energy storage has certain constraints: .

[0040] S3. Solve using a two-layer optimization framework: 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 sum of total costs, and the operation layer includes various constraints related to system operation.

[0041] S31. Planning Layer (Capacity Optimization): Select a heuristic algorithm (such as a genetic algorithm or particle swarm optimization) and randomly initialize a set of individuals. Each individual contains planning variables such as the electrical energy storage capacity, hydrogen energy storage capacity, fuel cell rated power, and electrolyzer rated power. The resulting capacity combinations are passed to the operation layer for simulation evaluation.

[0042] S32, Operation Layer (Simulation Evaluation): Based on the given load demand, wind and solar output time series data, and the equipment capacity parameters transmitted by the planning layer, a year-round operation simulation is performed. The simulation method is as follows: First, the net load is calculated, which is the load demand for the current period minus the wind and solar output to obtain the net load value. The simulation evaluation is performed based on the following conditions: Net load > 0, that is, power shortage occurs: priority is given to calling on energy storage to discharge to meet the net load; if there is still a power gap after the energy storage discharge, the fuel cell is started to generate electricity to supplement it; if the fuel cell still cannot meet all the demand, the load shedding operation is performed.

[0043] Net load < 0, that is, there is surplus electricity: the surplus electricity is used to charge the energy storage first; if the maximum charging power is reached or there is still surplus electricity after the energy storage is fully charged, the electrolyzer is started to produce hydrogen; if there is still surplus electricity after the electrolyzer is running at full power or the hydrogen storage equipment reaches the maximum allowable storage capacity, this part of the wind and solar power will be discarded.

[0044] S33. Result Feedback and Individual Updates: After the simulation is complete, the cumulative annual load loss and wind and solar curtailment are calculated and uploaded to the planning layer. The planning layer calculates the fitness value of each individual using the total cost formula and ranks them accordingly. Subsequently, a new generation of individuals is generated according to the rules of the selected heuristic algorithm (such as selection, crossover, mutation, and particle position update).

[0045] 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 any of the termination conditions are met, the current optimal individual is output; otherwise, return to step S32 to continue the simulation and iterative update.

[0046] Finally, it should be noted that the above 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 in the scope of protection of the present invention.

Claims

1. A method for planning an independent microgrid electricity-hydrogen energy storage system taking into account energy supply reliability, characterized in that: The following steps are involved: S1. Construct an objective function with the goal of minimizing the total cost of the system; S2. Establish a system operation constraint set, including: Power balance constraints: ensuring 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 loss constraint: limit the upper limit of load loss power in each period and the upper limit of the total annual load loss; Wind and solar curtailment constraints: set an upper limit on the annual wind and solar curtailment rate; Equipment characteristic constraints: covering fuel cell efficiency model, electrolyzer hydrogen production rate model, electric energy storage charge and discharge state model, and hydrogen energy storage reserve limit model; S3, using a two-layer optimization framework to solve: Planning layer: Optimize the rated capacity of electric energy storage, rated reserves of hydrogen energy storage, rated power of fuel cells, and rated power of electrolyzers; Operation layer: Based on the given load demand, wind and solar output time series data, and the capacity parameters transmitted by the planning layer, it simulates the operation strategy for each period of the year and feeds back the load loss and wind and solar curtailment to the planning layer; The capacity parameters are iteratively updated through a heuristic algorithm until the convergence conditions are met, and the optimal electric-hydrogen energy storage configuration solution is output.

2. The independent microgrid electricity-hydrogen energy storage planning method considering energy supply reliability according to claim 1 is characterized in that: The total cost in step S1 Including equipment configuration costs and system operating costs : 。 3. The independent microgrid electricity-hydrogen energy storage planning method considering energy supply reliability according to claim 2 is characterized in that: The net present value method is used to equate the annual operating cost of the independent microgrid to the system operating cost of the entire planning period. The net present value method for calculating the system operating cost is as follows: in, represents the annual operating cost of an independent microgrid, represents the capital recovery coefficient, represents the annual interest rate, represents the planning cycle, represents the simulation period throughout the year, represents the net present value of operating costs, 、 Represent the unit cost of lost load and the unit cost of abandoned wind and solar power, 、 Respectively Unit load loss power and unit abandoned wind and solar power at each moment.

4. The independent microgrid electricity-hydrogen energy storage planning method considering energy supply reliability according to claim 2 is characterized in that: Equipment configuration cost The calculation method is as follows: in, 、 、 、 They represent the unit power cost of electric energy storage, hydrogen energy storage, fuel cell and electrolyzer, respectively. 、 、 、 They represent the rated power of electric 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. Indicates the energy-to-power ratio of electrical energy storage.

5. The independent microgrid electricity-hydrogen energy storage planning method considering energy supply reliability according to claim 1 is characterized in that: The power balance constraint in step S2 is: in, 、 They represent the predicted wind and solar power and the abandoned wind and solar power respectively. 、 Respectively represent the energy storage discharge power and charging power, represents the mass flow rate of hydrogen flowing into the fuel cell, represents the fuel cell efficiency, Indicates the high calorific value of hydrogen, 、 Respectively represent the power consumed by the electric load and the power lost by the load, Indicates the power consumption of the electrolytic cell.

6. The independent microgrid electricity-hydrogen energy storage planning method considering energy supply reliability according to claim 5 is characterized in that: The constraint conditions of the load loss constraint in step S2 are: in, Indicates the maximum load loss during each period of operation. Indicates the permissible load loss in the whole year. Indicates the simulation period throughout the year.

7. The independent microgrid electricity-hydrogen energy storage planning method considering energy supply reliability according to claim 5 is characterized in that: The constraints for curtailing wind and solar power in step S2 are: in, It is the maximum wind and solar power curtailment rate throughout the year.

8. The independent microgrid electricity-hydrogen energy storage planning method considering energy supply reliability according to claim 5 is characterized in that: The equipment characteristic constraints in step S2 include fuel cell characteristic constraints, electrolyzer characteristic constraints, electrical energy storage characteristic constraints, and hydrogen energy storage characteristic constraints: (1) Fuel cell characteristic constraints Fuel cells are connected in series and parallel to obtain a larger fuel cell. The fuel cell voltage is calculated as follows: in, represents the DC voltage of the fuel cell, represents the fuel cell temperature, 、 、 Represent hydrogen pressure, oxygen pressure and standard atmospheric pressure respectively. Indicates the voltage fluctuation characteristics due to the dynamic characteristics of hydrogen and oxygen; in, is a constant, Indicates the fuel cell current size, Indicates the time delay between hydrogen and oxygen, Represents the convolution operation; The fuel cell output power is: in, is the number of fuel cells; The fuel cell efficiency calculation method is: in, Indicates the high calorific value of hydrogen, Represents the mass flow rate of hydrogen flowing into the fuel cell; The fuel cell output power limits are as follows: ； (2) Electrolytic cell characteristic constraints The relationship between the hydrogen production rate and power consumption of the electrolyzer is as follows: in, represents the hydrogen production rate of the electrolyzer, represents the electrolyzer efficiency, represents the electrolytic cell current density, represents the electrolytic cell voltage, represents the Faraday constant; The calculation method of electrolytic cell voltage is: in, Indicates the actual voltage of the electrolytic cell, 、 、 、 、 The ohmic voltage caused by the electrolytic cell external voltage, reversible voltage, activation voltage, gas propagation voltage and polymer membrane resistance respectively; The voltage across the battery under zero current conditions is calculated as follows: in, represents the open circuit battery voltage, represents the gas constant, represents the gas temperature, Indicates oxygen pressure, Indicates water activity; The voltage fluctuation caused by the electrochemical characteristics of the electrolyzer is expressed by the activation voltage as follows: in, represents the charge transfer coefficient used to describe the electrochemical reaction kinetics, represents the electrolytic cell current, Indicates the electrolytic cell current when the voltage drop is significant; The gas propagation voltage is given by: in, represents the constant term coefficient, represents the current limit for maximum gas propagation; The ohmic voltage drop due to the PEM resistance is shown below: in, 、 、 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 electrical energy storage characteristics Energy storage constraints include charge and discharge power constraints, charge and discharge identification constraints, and remaining energy change constraints. The energy storage charge and discharge power constraints are as follows: in, 、 Respectively The discharge flag and charge flag at the moment, 、 They represent the lower and upper limits of the battery's energy storage capacity. Indicates the remaining energy of the electric energy storage. 、 Respectively represent the discharge efficiency and charging efficiency of electric energy storage; The remaining energy change constraint is as follows: in, Represents the self-consumption rate of the electric energy storage device, 、 Respectively represent the discharge power and charging power of the energy storage; The charge and discharge flags are constrained as follows: ； (4) Constraints of hydrogen energy storage characteristics The changes in hydrogen energy storage are as follows: in, The remaining hydrogen for hydrogen energy storage, Represents the mass flow rate of hydrogen flowing into the fuel cell; Since hydrogen energy storage pressure is subject to certain restrictions, hydrogen energy storage has certain constraints: in, Indicates the rated storage mass of hydrogen energy storage.

9. The independent microgrid electricity-hydrogen energy storage planning method considering energy supply reliability according to claim 1 is characterized in that: The method for running layer simulation evaluation in step S3 is: When the net load is greater than 0, the system will sequentially call for energy storage discharge, fuel cell power generation, and load shedding according to the power shortage situation; When the net load is <0, the three operations of energy storage charging, electrolyzer hydrogen production, and wind and solar power curtailment are called upon in sequence according to the power surplus situation.

10. The independent microgrid electricity-hydrogen energy storage planning method considering energy supply reliability according to claim 1 is characterized in that: In step S3, the capacity parameter is iteratively updated by a heuristic algorithm until the convergence condition is met, including 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 whether the termination condition is met, and if so, output the current optimal individual; The termination condition is that the preset maximum number of iterations is reached, or the fitness value of the optimal individual does not change in several consecutive iterations.

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