Multi-stack rotation method considering life decline of reversible proton exchange membrane fuel cell

Abstract

The invention discloses a multi-stack rotation method considering life decline of a reversible proton exchange membrane fuel cell, and relates to the technical field of control of an electro-hydrogen energy system. Under the condition that power distribution is carried out on the multiple electric piles of the reversible proton exchange membrane fuel cell, if the rotation time reaches a preset duration, the power of the multiple electric piles is optimized by taking the maximum daily income of an electro-hydrogen energy system where the reversible proton exchange membrane fuel cell is located as a target, and the optimal power of the electric piles is determined; respectively acquiring the life loss of each electric pile in the historical rotation time period, and sorting the plurality of electric piles according to the life loss; calculating the working power of each galvanic pile according to the optimal power of the galvanic pile, and respectively obtaining the voltage change rate under each working power; and based on the sequence of the plurality of electric piles, according to the principle that the electric piles with higher service life loss distribute the working power with lower voltage change rate, distributing the working power to each electric pile. The method solves the problem of the short-plate effect of multiple electric piles, and the service lives of the multiple electric piles can be balanced.

Description

Technical Field

[0001] The present invention relates to the technical field of control of electric hydrogen energy systems, and in particular to a multi-stack rotation method taking into account the life degradation of reversible proton exchange membrane fuel cells. Background Art

[0002] Currently, in practical projects, to avoid the short-board effect, where most reversible proton exchange membrane fuel cells (RPEMFCs) experience acceptable lifespan losses, but a small number of RPEMFCs experience significant lifespan losses and approach scrappage due to factors such as excessive operating hours, a multi-stack rotation system is often employed. The primary purpose of this rotation is to balance power distribution across the stacks, ensuring a uniform overall lifespan and extending their service life.

[0003] The current rotation strategy is typically based on a "sequential rotation" principle. First, the stacks are ranked and numbered, and then a rotation time T is set. After each time T elapses, the power generated by the power allocation control strategy is distributed to each stack in turn.

[0004] However, the rotation method in the existing technology still has the problem of uneven life of each fuel cell stack, and it is difficult to effectively alleviate the short board effect of multiple fuel cell stacks. Summary of the Invention

[0005] Based on this, it is necessary to provide a multi-stack rotation method that takes into account the life degradation of reversible proton exchange membrane fuel cells to address the above technical problems.

[0006] The present invention adopts the following technical solutions: The present invention provides a multi-stack rotation method considering the life degradation of a reversible proton exchange membrane fuel cell, comprising: In the case of power allocation for multiple stacks of reversible proton exchange membrane fuel cells, if the rotation time reaches a preset time, the power of the multiple stacks is optimized with the goal of maximizing the daily revenue of the electric hydrogen energy system where the reversible proton exchange membrane fuel cells are located to determine the optimal power of the stacks; Obtaining the life loss of each stack of the reversible proton exchange membrane fuel cell in a historical rotation period, and sorting the multiple stacks according to the life loss; the historical rotation period is the rotation period before the current moment; Calculate the operating power of each stack of the reversible proton exchange membrane fuel cell based on the optimal power of the stack, and obtain the voltage change rate at each operating power; Based on the ranking of multiple fuel cells, operating power is allocated to each fuel cell according to the principle that a fuel cell with greater life loss is allocated operating power with a smaller voltage change rate.

[0007] Optionally, with the goal of maximizing the daily revenue of the electric-hydrogen energy system in which the reversible proton exchange membrane fuel cell is located, the power of the multiple fuel cell stacks is optimized to determine the optimal power of the fuel cell stacks, including: With the goal of maximizing the daily revenue of the electric-hydrogen energy system, the power of the fuel cell stack is optimized using a particle swarm algorithm, and the optimal solution obtained is determined as the optimal power of the fuel cell stack. The calculation formula for the daily revenue of the electric-hydrogen energy system is: ; in, The daily income of the electric hydrogen energy system; for Operating income at the time of the event; for The operating cost at each moment; ; in, for Total amount of hydrogen produced at the time; is the selling price of hydrogen; ; ; ; ; in, express The purchase cost at the time, express Operation and maintenance costs at all times, express The penalty cost of the moment, for The total amount of hydrogen purchased at the time, is the purchase price of hydrogen, for The electricity that needs to be purchased at any time, for The electricity price at the time, refer to The total amount of hydrogen produced or consumed at any moment, is the unit price of equipment operation and maintenance, for The total load shedding at the moment, is the load shedding penalty coefficient; The power balance condition in the process of optimizing the power of multi-stack is: ; in, 、 They are Wind and photovoltaic power generation at all times, 、 They are The power generated by electricity or consumed by electrolysis at any moment, express The load power of the system at that moment.

[0008] Optionally, respectively obtaining the life loss of each stack of the reversible proton exchange membrane fuel cell during a historical rotation period includes: For any fuel cell stack, determine the working mode of the fuel cell stack during the historical rotation period; If the working mode of the fuel cell stack is electrolysis mode, the life loss of the fuel cell stack is determined based on the electrolysis voltage loss of the fuel cell stack during the historical rotation period; If the working mode of the fuel cell stack is power generation mode, the life loss of the fuel cell stack is determined based on the output voltage loss of the fuel cell stack during the historical rotation period; If the working mode of the fuel cell stack includes the electrolysis mode and the power generation mode, the life loss of the fuel cell stack is determined based on the sum of the internal electrolysis voltage loss and the output voltage loss of the fuel cell stack during the historical rotation period.

[0009] Optionally, the operating power of each stack of the reversible proton exchange membrane fuel cell is calculated based on the optimal power of the stack, including: The difference between the total input power of all the stacks of the reversible proton exchange membrane fuel cell and the total optimal power is determined as the power difference; The operating power of each fuel cell stack is obtained by performing fuzzy control processing on the power difference.

[0010] Optionally, the operating power of each fuel cell stack is obtained by performing fuzzy control processing on the power difference, including: According to the power difference, the fuzzy input is determined; According to the preset fuzzy control rules, the fuzzy relationship is determined; Determine the fuzzy output according to the fuzzy set and fuzzy relationship corresponding to the fuzzy input; Defuzzify the fuzzy output to obtain the control quantity; The operating power of each fuel cell stack is determined based on the control quantity and the preset fuzzy control strategy.

[0011] Optionally, the operating power of each fuel cell stack is determined according to the control quantity and a preset fuzzy control strategy, including: When the control quantity is the first fuzzy output quantity, it is determined that the operating power of all battery stacks is 0; When the control quantity is the second fuzzy output quantity, it is determined that the working power of n stacks is the optimal power, and the working power of one stack is , the remaining battery stacks do not work; , Indicates the total input power, Indicates optimal power; When the control quantity is the third fuzzy output quantity, it is determined that the operating power of all battery stacks is the optimal power; When the control quantity is the fourth fuzzy output quantity, the total working power is used as the constraint condition and the minimum total cost is used as the optimization goal to optimize the working power of each fuel cell stack and obtain the working power of each fuel cell stack; When the controlled quantity is the fifth fuzzy output quantity, it is determined that the operating power of all fuel cell stacks is the rated power.

[0012] Optionally, the voltage change rate at each operating power is obtained separately, including: For any operating power, if the stack operates in electrolysis mode, the voltage change rate under the operating power is determined based on the relationship between the operating power and the rated power; If the fuel cell stack operates in the power generation mode, the voltage change rate under the operating power is determined to be a preset value.

[0013] Optionally, the voltage change rate under the working power corresponding to the electrolysis mode is calculated as follows: ; in, is the voltage change rate under the working power corresponding to the electrolysis mode; Indicates the working power of the battery stack; Indicates the rated power of the battery stack.

[0014] The present invention provides a multi-stack rotation device taking into account the life degradation of a reversible proton exchange membrane fuel cell, comprising: a determination module for, when power is allocated to multiple stacks of reversible proton exchange membrane fuel cells, optimizing the power of the multiple stacks and determining the optimal power of the stacks with the goal of maximizing the daily revenue of the electric-hydrogen energy system in which the reversible proton exchange membrane fuel cells are located if the rotation time reaches a preset time; A sorting module is used to respectively obtain the life loss of each stack of the reversible proton exchange membrane fuel cell in a historical rotation period, and sort the multiple stacks according to the life loss; the historical rotation period is the rotation period before the current moment; A calculation module is used to calculate the operating power of each stack of the reversible proton exchange membrane fuel cell according to the optimal power of the stack, and obtain the voltage change rate at each operating power; The allocation module is used to allocate working power to each battery stack based on the order of multiple battery stacks and the principle that the battery stack with greater life loss is allocated working power with a smaller voltage change rate.

[0015] The present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the multi-stack rotation method considering the life degradation of a reversible proton exchange membrane fuel cell.

[0016] The present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the multi-stack rotation method taking into account the life degradation of a reversible proton exchange membrane fuel cell is implemented.

[0017] At least one of the above technical solutions adopted by the present invention can achieve the following beneficial effects: In the present invention, when power is distributed to multiple stacks of a reversible proton exchange membrane fuel cell, the life loss of each stack during the historical rotation period and the voltage change rate of the stack at each working power are calculated, so that the stack with a larger life loss is allocated a working power with a smaller voltage change rate, and the stack with a smaller life loss is allocated a working power with a larger voltage change rate. In this way, the life loss of the stack with a larger life loss is slowed down, and the life loss of each stack is balanced, thereby ensuring the balanced life of each stack and effectively alleviating the short-board effect of multiple stacks. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of a rotation strategy under a simple start-stop control strategy; Figure 2 This is a schematic diagram of a rotation strategy under a fuzzy control strategy; Figure 3 A schematic flow chart of a multi-stack rotation method for considering the life degradation of a reversible proton exchange membrane fuel cell provided by the present invention; Figure 4 This is a structural schematic diagram of an electric hydrogen energy system based on RPEMFC of the present invention; Figure 5 A schematic diagram of a process for determining the optimal power of a fuel cell stack provided by the present invention; Figure 6 A schematic diagram of the working principle of the fuzzy controller provided by the present invention; Figure 7 The improved fuzzy control strategy workflow diagram provided by the present invention; Figure 8 A schematic diagram of a rotation strategy based on the life loss of RPEMFC provided by the present invention; Figure 9 This is a schematic diagram of the clean energy output curve and load curve; Figure 10 This is a typical daily time-of-use electricity price chart; Figure 11 This is a schematic diagram of the stack life loss under a simple start-stop control strategy; Figure 12 This is a schematic diagram of the stack life loss under the fuzzy control strategy; Figure 13 A schematic diagram of a computer device provided by the present invention for implementing a multi-stack rotation method taking into account the life degradation of a reversible proton exchange membrane fuel cell. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] The current rotation strategy is usually based on the principle of "sequential rotation". First, the stacks are sorted and numbered, and then the rotation time T is set. After each rotation time T, the power obtained by the power distribution control strategy is distributed to each stack in turn. When a simple start-stop control strategy is adopted, the rotation strategy is as follows: Figure 1 shown.

[0022] The battery stack has three states: rated power, random power and shutdown. n The rated power of each battery stack is P_rate , the optimal power is P_0 , the actual working power is P_i , the total power input or output is P_ total .when When all the stacks are working at rated power, the life loss of each stack is the same, so no rotation is performed. Figure 1 As shown in Figure (a); when When m The stacks are in rated power state, one stack is in random power state, and the rest of the stacks are in shutdown state. T Time, before m The first stack is in rated power state, the second ( m +1) ~ ( n -1) The stack is shut down, n Each battery stack works at random power;T ~ 2 T When the first stack works at random power, the second ~ ( m +1) stack is in rated power state, the ( m +2) ~ n The stack is shut down; in 2 T ~ 3 T When the first stack is shut down, the second stack works at random power, and the third stack works at random power. m +2) stacks are in rated power state, the ( m +3) ~ n The battery stack is shut down, and the cycle continues. Figure 1 As shown in Figure (b).

[0023] Among the control strategies for multi-stacks, the simple start-stop control strategy has the widest application range due to its simplicity and clarity. Its working control strategy is as follows: (1) When When the battery stack is not started; (2) When When only one battery stack is started, the working power is ; (3) When When only one battery stack is started, the working power is ; (4) When When the second battery stack starts, , .

[0024] By analogy, when All fuel cells operate at maximum power.

[0025] The core idea of ​​the simple start-stop control strategy is to start as few fuel cells as possible in the same time period, avoiding frequent switching of fuel cells. However, its disadvantage is that it does not take into account the working efficiency of the fuel cell and only meets the power requirements of the fuel cell, resulting in low overall working efficiency.

[0026] When RPEMFC is electrolyzing, a fuzzy control strategy is adopted. For the fuzzy control strategy, RPEMFC has an optimal power point, and its rotation strategy is as follows: Figure 2 shown.

[0027] exist There are two situations. Sometimes, there are m When the stacks are working at the optimal power, one stack is working at the random power, and the other stacks are in the shutdown state; When m1 stack works at rated power, 1 stack works at random power, and the rest of the stacks are at optimal power. T Time, before m The stack is in the best power state, the m +1)~ ( n -1) The stack is shut down, n Each battery stack works at random power; T ~ 2 T When the first stack works at random power, the second ~ ( m +1) stack is in the optimal power state, the ( m +2) ~ n The stack is shut down; in 2 T ~ 3 T When the first stack is shut down, the second stack works at random power, and the third stack works at random power. m +2) stacks are in optimal power state, and the ( m +3)~ n The battery stack is shut down, such as Figure 2 As shown in Figure (a). At 0~ T Time, before m The first stack is in rated power state, the second ( m +1) ~ ( n -1) The stack is in the optimal power state, n Each battery stack works at random power; T ~ 2 T When the first stack works at random power, the second ~ ( m +1) stack is in rated power state, the ( m +2) ~ n The stack is in the optimal power state; T ~ 3 T When the first battery stack is in the optimal power state, the second battery stack works at random power, and the third battery stack is in the optimal power state. m +2) stack is in rated power state, the ( m +3) ~ n The battery stack is in the optimal power state, such as Figure 2 As shown in Figure (b).

[0028] This fuzzy control strategy takes the segmented interval of input power as the basic premise. By fuzzifying the difference between the mean input power and the power for optimal hydrogen production efficiency, an input power allocation method that helps improve electrolysis efficiency is formulated within the corresponding power segment interval. At the same time, with the help of a feedback comparison mechanism, the input power is continuously and dynamically allocated to achieve a reasonable allocation of input power, ultimately ensuring that the operating power between groups of the entire system is in a stable and efficient state. This method can not only effectively improve the safety of system operation, but also maximize the potential of the system's hydrogen production efficiency, achieving efficient energy utilization and stable system operation. Its working control strategy is as follows:

[0029] make , then according to The size of can be divided into five intervals, namely ZB (negative large), ZS (negative small), Z (zero), PS (positive small), and PB (positive large).

[0030] (1) When , the battery stack will not start; (2) When , then part of the stack works at the optimal power, and part is not started; (3) When , then the battery stack operates at the optimal power; (4) When , then part of the stack works at the optimal power point, and part works at the rated power point; (5) When , the battery stack operates at the rated power point.

[0031] While this fuzzy control strategy can effectively improve the overall efficiency of the fuel cell stack, it has certain limitations, as it restricts the stack to operation only at shutdown, optimal power, and rated power points. Furthermore, using the difference between the mean input power and the optimal hydrogen production efficiency power as input increases the ZB interval threshold, resulting in zero hydrogen production efficiency at low input power levels.

[0032] Although the ordinary rotation strategy has alleviated the "shortboard effect" of multi-stacks to a certain extent, it is impossible to quantitatively calculate the life degradation of RPEMFC. During the rotation process, it can only be rotated blindly in order according to the stack number, resulting in a huge difference in life loss between each stack. Therefore, a multi-stack rotation method considering the life degradation of reversible proton exchange membrane fuel cells is proposed. This method proposes a rotation strategy considering the life degradation of RPEMFC. Through durability experiments on RPEMFC in power generation and electrolysis modes, the life degradation in the two modes is quantitatively analyzed, and the life degradation value is quantified.

[0033] The technical solutions provided by various embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0034] Figure 3 This is a flow chart of a multi-stack rotation method considering the life degradation of a reversible proton exchange membrane fuel cell in the present invention, which specifically includes the following steps: S101, when allocating power to multiple stacks of reversible proton exchange membrane fuel cells, if the rotation time reaches a preset duration, the power of the multiple stacks is optimized with the goal of maximizing the daily revenue of the electric hydrogen energy system where the reversible proton exchange membrane fuel cells are located to determine the optimal power of the stacks.

[0035] RPEMFC is a device with unique performance. It can realize bidirectional operation in power generation mode and electrolysis mode: in electrolysis mode, it can make full use of the electricity provided by clean energy such as wind power and photovoltaics to electrolyze water to generate hydrogen and oxygen. By storing hydrogen, energy storage can be achieved, providing an important basis for subsequent energy utilization; in power generation mode, the chemical energy stored in hydrogen is converted into electrical energy by reacting hydrogen and oxygen. This bidirectional operation capability makes RPEMFC highly flexible and energy adaptable. Based on this, this method constructs an electric hydrogen energy system based on RPEMFC, and its structure is as follows: Figure 4 As shown in the figure, the system includes clean energy sources such as photovoltaic and wind power, interconnection lines, RPEMFC, and a hydrogen energy market. Clean energy is the system's primary energy source, supporting the power load. The system is connected to the power grid via the interconnection lines, enabling it to purchase and sell electricity from the grid. The hydrogen energy market provides a platform for the system's hydrogen sales and purchases, enabling it to better integrate into the market and realize the economic value of energy.

[0036] When clean energy output is sufficient, the RPEMFC unit leverages its advantages in electrolysis mode to convert excess electricity into hydrogen, which is then sold through the system's connected hydrogen market, achieving economic growth. When clean energy output is insufficient, the system considers real-time electricity prices and the current hydrogen production efficiency of the fuel cell stack to ensure cost-effectiveness in both electricity purchase and electrolysis. When clean energy output falls short of the electrical load, the RPEMFC unit rapidly switches to power generation mode, generating electricity from hydrogen. This electricity is then used to meet load demand, ensuring system operation and energy supply continuity. During this process, the system considers the economic cost of purchasing electricity from the grid, the cost of generating electricity in the RPEMFC power generation mode, the cost of electrolysis in the electrolysis mode, the revenue from hydrogen sales, and the capacity of the interconnector lines. It then rationally adjusts the RPEMFC unit's operating power and distributes power to each stack using a multi-stack control strategy to ensure the system can consistently and stably deliver sufficient power to the load at the highest possible cost.

[0037] In one embodiment, with the goal of maximizing the daily revenue of the electric-hydrogen energy system in which the reversible proton exchange membrane fuel cell is located, the power of multiple fuel cell stacks is optimized to determine the optimal power of the fuel cell stack, including: with the goal of maximizing the daily revenue of the electric-hydrogen energy system, the power of the fuel cell stack is optimized using a particle swarm algorithm, and the optimal solution obtained by the optimization is determined as the optimal power of the fuel cell stack.

[0038] Optionally, the daily income of the electric hydrogen energy system is composed of operating income and operating costs. The calculation formula of the daily income of the electric hydrogen energy system is: (1); in, The daily income of the electric hydrogen energy system; for Operating income at the time; for The operating cost of the moment.

[0039] The system's operating income mainly comes from the production of hydrogen through the electrolysis of water by RPEMFC. The generated hydrogen is sold through the hydrogen market and can be expressed as: (2); in, for Total amount of hydrogen produced at the time; is the selling price of hydrogen.

[0040] The operating cost of the system consists of three parts: purchase cost, operation and maintenance cost, and penalty cost. It can be expressed as:

[0041] (3); in, express The acquisition cost at the time, express Operation and maintenance costs at all times, express The penalty cost of the moment.

[0042] The purchase cost includes the cost of hydrogen and the cost of electricity, which can be expressed as: (4); in, for The total amount of hydrogen purchased at the time, is the purchase price of hydrogen, for The electricity that needs to be purchased at any time, for The electricity price at the time.

[0043] Operation and maintenance costs refer to the operation and maintenance costs of RPEMFC and the transportation costs of hydrogen, etc., which can be expressed as: (5); (6); in, refer to The total amount of hydrogen produced or consumed at any moment, is the unit price of equipment operation and maintenance, for The total load shedding at the moment, is the load shedding penalty factor.

[0044] The power balance condition in the process of optimizing the power of multi-stack is: (7); in, 、 They are Wind and photovoltaic power generation at all times, 、 They are The power generated by electricity or consumed by electrolysis at any moment, express The load power of the system at that moment.

[0045] It should be noted that the optimal power is or .

[0046] The particle swarm optimization (PSO) algorithm is an optimization algorithm based on swarm intelligence, inspired by observations of the behavior of biological swarms in nature. Proposed by Kennedy and Eberhart in 1995, the algorithm simulates the foraging behavior of groups such as bird flocks and fish schools. Within these groups, individuals achieve efficient search and decision-making through simple behavioral rules and mutual collaboration. For example, when a flock of birds searches for food, each bird does not know the exact location of the food, but they adjust their flight direction and speed based on their own experience and information from other birds in the group, ultimately locating the food. The particle swarm algorithm applies this principle of swarm behavior to optimization problems, treating each potential solution to the optimization problem as a "particle" in the search space. A particle swarm is composed of multiple such particles, which work together to find the optimal solution within the search space.

[0047] In this invention, in order to ensure that the particle swarm can conduct a wide search of the global range in the early stage and conduct a precise search of the local area in the later stage, an adaptive strategy is adopted to adjust the inertia weight, that is, to improve the efficiency and accuracy of the algorithm at different stages: (8); in, For particles i In the d Inertia weight after iterations; 、 The minimum and maximum inertia weight coefficients are set in advance, and are generally set to 0.4 and 0.9; For the d The maximum fitness of all particles at the iteration; For the d The average fitness of all particles at the iteration; Particles i In the d The fitness after iterations.

[0048] With the goal of maximizing the daily revenue of the electric hydrogen energy system, the power of the fuel cell stack is optimized through the adaptive weighted particle swarm algorithm, and the optimal solution obtained is determined as the optimal output power under the optimal economy of the fuel cell stack. The specific process is as follows: Figure 5 As shown, the specific steps include: (1) Construct an electric-hydrogen energy system based on RPEMFC and determine basic parameters, such as real-time electricity price, hydrogen purchase and sales price, etc., with the system daily revenue as the fitness function.

[0049] (2) Input real-time electric load, wind power and photovoltaic power output, that is 、 and .

[0050] (3) Initialize the parameters of the particle swarm algorithm, reasonably set the number of particles, and adjust parameters such as speed, inertia weight, and learning coefficient. The particle position includes 、 、 and .

[0051] (4) Calculate the optimal operating mode of the RPEMFC device based on different multi-stack control strategies.

[0052] (5) Calculate the fitness function of all particles, update the global optimal position and individual optimal position by comparison, and recalculate the inertia weight and particle velocity.

[0053] (6) Continue to execute the fourth and fifth steps, iterate to the maximum number of times, and judge whether the system daily income converges; if converged, end the loop and output the optimal working power, that is, the optimal power.

[0054] S102, respectively obtain the life loss of each stack of the reversible proton exchange membrane fuel cell in a historical rotation period, and sort the multiple stacks according to the life loss; the historical rotation period is the rotation period before the current moment.

[0055] The historical duty period may include all duty periods before the current moment.

[0056] The fuel cell stack operates in two modes: electrolysis mode and power generation mode. When the operating current is fixed, in electrolysis mode, as the battery ages, the electrolysis voltage increases, meaning that power consumption increases for a given hydrogen production rate. In power generation mode, however, as the battery ages, the output voltage decreases, meaning that power generation decreases for a given hydrogen consumption rate. Therefore, the lifespan loss of the RPEMFC in these two modes can be characterized by the rate of change of the electrolysis voltage and the rate of change of the output voltage. The amount of electrolysis voltage loss and output voltage loss is correlated with the rate of change of the RPEMFC voltage in these two modes.

[0057] Optionally, the life loss of each stack of the reversible proton exchange membrane fuel cell before the historical rotation period is obtained separately, including: for any stack, determining the working mode of the stack during the historical rotation period; if the working mode of the stack is the electrolysis mode, determining the life loss of the stack based on the electrolysis voltage loss of the stack during the historical rotation period; if the working mode of the stack is the power generation mode, determining the life loss of the stack based on the output voltage loss of the stack during the historical rotation period; if the working mode of the stack includes the electrolysis mode and the power generation mode, determining the life loss of the stack based on the sum of the internal electrolysis voltage loss and the output voltage loss of the stack during the historical rotation period.

[0058] If the working mode of the fuel cell stack is the electrolysis mode, then the electrolysis voltage loss of the fuel cell stack in the historical rotation period is determined, including: obtaining the electrolysis voltage change rate in each time period in the historical rotation period, weighting the electrolysis voltage change rate in all time periods, and obtaining the electrolysis voltage loss of the fuel cell stack in the historical rotation period, and determining the electrolysis voltage loss as the life loss of the fuel cell stack.

[0059] Specifically, the calculation formula for the electrolysis voltage loss of the stack during the historical rotation period is: (9); in, Indicates the electrolysis voltage loss during the rotation period in electrolysis mode. Indicates t The electrolysis voltage change rate within a moment, each moment can be regarded as a time period, and the summation formula here is to sum the electrolysis voltage change rate of all time periods within the historical rotation period.

[0060] If the working mode of the fuel cell stack is the power generation mode, the life loss of the fuel cell stack is determined based on the output voltage loss of the fuel cell stack during the historical rotation period, including: dividing the historical rotation period into multiple time periods, obtaining the output voltage change rate in each time period, adding up the output voltage change rates in all time periods, obtaining the output voltage loss of the fuel cell stack during the historical rotation period, and determining the output voltage loss as the life loss of the fuel cell stack.

[0061] Specifically, the calculation formula for the output voltage loss of the stack during the historical rotation period is: (10); in, Indicates the output voltage loss during the rotation period in power generation mode. Indicates t The output voltage change rate within a moment, each moment can be regarded as a time period, and the summation formula here is to sum the output voltage change rates of all time periods within the historical rotation period.

[0062] The life loss of RPEMFC in two modes is characterized by the change rate of electrolysis voltage and output voltage, which is specifically expressed as: (11); in, It represents the total voltage loss in both electrolysis mode and power generation mode, i.e. life loss.

[0063] Sorting the plurality of battery stacks according to life loss includes: sorting the battery stacks in ascending order of life loss.

[0064] S103 , calculating the operating power of each stack of the reversible proton exchange membrane fuel cell according to the optimal power of the stack, and obtaining the voltage change rate at each operating power respectively.

[0065] Optionally, the operating power of each stack of the reversible proton exchange membrane fuel cell is calculated based on the optimal power of the stack, including: determining the difference between the total input power of all stacks of the reversible proton exchange membrane fuel cell and the total optimal power as the power difference; and obtaining the operating power of each stack by performing fuzzy control processing on the power difference.

[0066] Optionally, the operating power of each fuel cell stack is obtained by performing fuzzy control processing on the power difference, including: determining the fuzzy input based on the power difference; determining the fuzzy relationship based on preset fuzzy control rules; determining the fuzzy output based on the fuzzy set and fuzzy relationship corresponding to the fuzzy input; defuzzifying the fuzzy output to obtain the control quantity; and determining the operating power of each fuel cell stack based on the control quantity and the preset fuzzy control strategy.

[0067] Specifically, by modifying the input of the fuzzy controller and the allocation rule of each interval, an improved segmented fuzzy control method is obtained.

[0068] Figure 6 The working principle of the fuzzy controller is shown. The input of the fuzzy controller is the difference between the input power and the total optimal power, that is, Similarly, The corresponding intervals are divided into ZB (negative large), ZS (negative small), Z (zero), PS (positive small), PB (positive large). According to the set fuzzy control rules, different outputs can be obtained, which are also divided into ZB (negative large), ZS (negative small), Z (zero), PS (positive small), PB (positive large). The outputs in different intervals correspond to different power allocation schemes. At the same time, the real-time input power of the RPEMFC stack is compared with the actual power, that is, , adjust the stack power again until .

[0069] The fuzzy control rule table is shown in Table 1. Under different fuzzy inputs, the controller needs to use different fuzzy rules to make decisions. The fuzzy relationship R It can be expressed as: (12).

[0070] Table 1 Fuzzy controller input The partition table is shown in Table 2. The input is mapped to the interval [-2, 2] through fuzzification, and different fuzzy sets have different membership degrees in the interval [-2, 2].

[0071] Table 2 The partition table of the fuzzy controller output u is shown in Table 3. Different fuzzy sets have different membership degrees in the interval [-4, 4]. The corresponding fuzzy sets can be obtained through fuzzy control rules, and the output of the fuzzy controller can be obtained by defuzzifying them.

[0072] Table 3 According to Table 1, Table 2 and Table 3, the fuzzy rules can be quantitatively calculated to obtain: (13); (14); (15); (16); (17).

[0073] Substituting formulas (13) to (17) into formula (12), we can obtain: (18).

[0074] when hour, ,at this time: (19); Then the controller output can be expressed as: (20).

[0075] According to the maximum membership principle, the control quantity should be selected as 4. Table 4 lists the fuzzy control responses.

[0076] Table 4 Optionally, determining the operating power of each fuel cell stack according to the control quantity and a preset fuzzy control strategy includes the following steps: S201: When the control quantity is the first fuzzy output quantity, it is determined that the operating power of all fuel cell stacks is 0.

[0077] The first fuzzy output is -4. When u=-4, all stacks are not started. .

[0078] S202, when the control quantity is the second fuzzy output quantity, it is determined that the working power of n stacks is the optimal power, and the working power of one stack is , the remaining battery stacks do not work; , Indicates the total input power, Indicates optimal power.

[0079] The second fuzzy output is -2. When u=-2, there are n+1 stacks started, of which n stacks work at the optimal power and the remaining stack works at the minimum power. and the optimal power, that is: (twenty one).

[0080] S203: When the control quantity is the third fuzzy output quantity, it is determined that the operating power of all fuel cell stacks is the optimal power.

[0081] The third fuzzy output is 0. When u=0, all fuel cells are started and operate at the optimal power, that is: (twenty two).

[0082] S204, when the control quantity is the fourth fuzzy output quantity, the operating power of each fuel cell stack is optimized with the total operating power as the constraint condition and the minimum total cost as the optimization goal to obtain the operating power of each fuel cell stack.

[0083] The fourth fuzzy output is 2. When u = 2, all fuel cells are started. When the total efficiency of the fuel cell is the highest, its hydrogen production reaches its maximum. Assuming that each fuel cell produces n_H2_i hydrogen when the input power is P_i, the objective function is to maximize the total hydrogen production, and the sum of the fuel cell power is the input power as the constraint condition, and the algorithm is used to solve it.

[0084] (twenty three).

[0085] Among them, when the control quantity is the fourth fuzzy output quantity, part of the fuel cell stack operates at the optimal power point, and part of the fuel cell stack operates at the rated power point.

[0086] S205: When the control quantity is the fifth fuzzy output quantity, it is determined that the operating power of all fuel cell stacks is the rated power.

[0087] The fifth fuzzy output is 4. When u=4, all fuel cells are started and operate at the rated power point, that is: (twenty four).

[0088] like Figure 7 As shown, Figure 7 To improve the fuzzy control strategy workflow diagram, for the improved fuzzy control strategy, when it is When the power distribution of multiple stacks is used, the operating power of all stacks is kept as close to the optimal power as possible while meeting the total power requirement. Under this strategy, the operating power of each stack is consistent, and the life loss of each stack is balanced.

[0089] Optionally, the voltage change rate at each working power is obtained separately, including: for any working power, if the fuel cell stack operates in electrolysis mode, the voltage change rate at the working power is determined based on the relationship between the working power and the rated power; if the fuel cell stack operates in power generation mode, the voltage change rate at the working power is determined to be a preset value.

[0090] Optionally, the voltage change rate under the working power corresponding to the electrolysis mode is calculated as follows: (25); in, is the voltage change rate under the working power corresponding to the electrolysis mode; Indicates the working power of the battery stack; Indicates the rated power of the battery stack.

[0091] Durability experiments were conducted on the RPEMFC in both power generation and electrolysis modes, and the lifetime degradation in both modes was quantitatively analyzed, with the lifetime degradation values ​​quantified. Specifically, the voltage change rate was calculated by selecting the phase in which the RPEMFC could operate stably and efficiently in both modes. In the electrolysis mode, the voltage change rate at a current of 25 A was used to calculate the electrolysis voltage loss (Equation (9)), and in the power generation mode, the voltage change rate at a current of 10 A was used to calculate the output voltage loss (Equation (10)).

[0092] Table 5 It can be seen from Table 5 that RPEMFC starts electrolysis after the electrolysis voltage is greater than 1.4 V. The rated voltage is 1.9 V, and the higher the electrolysis voltage, the greater the electrolysis power. Therefore, three power levels of high, medium, and low are set. The voltage change rate is different at different power levels, and formula (25) is obtained.

[0093] Since RPEMFC has a certain performance false recovery phenomenon in the power generation mode, it is impossible to calculate the voltage change rate under different working currents in the power generation mode in detail. Table 6 summarizes the overall voltage change rate of RPEMFC in the power generation mode.

[0094] Table 6 Based on Table 6, we get , that is, the default value is 1.96.

[0095] S104 , based on the order of the multiple fuel cells, allocate operating power to each fuel cell according to the principle that a fuel cell with a greater life loss is allocated an operating power with a smaller voltage change rate.

[0096] Life loss based on RPEMFC Establish a rotation strategy such as Figure 8 As shown. Every rotation time T, the life loss of each battery stack Calculate and sort, and in the next rotation time T, distribute the power through different stack optimization control strategies, and sort the voltage change rates corresponding to different powers to make the life loss A larger stack distributes power with a smaller voltage change rate, resulting in a loss of lifespan. A smaller battery stack distributes power with a larger voltage change rate to avoid the short board effect.

[0097] In order to verify the superiority and effectiveness of the proposed multi-RPEMFC stack control strategy, a certain electric-hydrogen energy system was selected as an example to compare the operation of the system under different control strategies. Figure 9 As shown, Figure 9 It is the clean energy output curve and load curve.

[0098] The power load is low between 10 PM and 7 AM, at around 650 kW. Between 9 AM and 7 PM, the load exceeds 1,200 kW, representing peak demand. Photovoltaic power generation is zero at night, generating between 6 AM and 8 PM, with peak output reaching 800 kW around 1 PM. Wind power generation, on the other hand, exhibits the opposite characteristics, generating high and stable power at night, around 1,400 kW, while decreasing during the day. The complementary nature of wind and solar power generation can reduce the number of operating mode switches in the RPEMFC system, effectively improving its efficiency and enhancing the system's economic value.

[0099] The electricity price on a typical day adopts the time-of-use price, such as Figure 10 As shown, Figure 10 This is a typical daily time-of-use electricity price chart. During peak hours, the price can reach 0.42 yuan / kWh, while during off-peak hours, it can be as low as 0.3 yuan / kWh.

[0100] The relevant parameters of the electric-hydrogen energy system are shown in Table 7.

[0101] Table 7 The population size of the particle swarm is set to 50, the maximum number of iterations is set to 100, the inertia weight ranges between 0.4 and 0.9, and the learning factor is set to 1.5.

[0102] Result analysis: Set the duty time T to 1 hour, Figure 11 The life loss of the battery stack under a simple start-stop control strategy is: Figure 11 Figure (a) shows the life degradation of each RPEMFC stack under the simple start-stop control strategy, when the no-rotation strategy, the common rotation strategy and the rotation strategy based on life degradation are adopted. Compared with the no-rotation strategy, the improvement effect of the common rotation strategy is not obvious, and the life loss of each stack is The maximum difference between the two strategies was only 0.01 mV. However, the strategy proposed in this work reduced the extreme difference in life loss between the stacks from 19.16 mV to 4.79 mV, making the performance and life loss of each stack more balanced. At the same time, the maximum life loss of the stack was 38.29 mV, an improvement of 19.29% from 47.44 mV under the previous two strategies. Figure 11 Figure (b) shows the life loss value of each fuel cell at each moment under the rotation strategy based on life decay.

[0103] Figure 12 is the stack life loss under the fuzzy control strategy, Figure 12Figure (a) shows the life degradation of each RPEMFC stack under the fuzzy control strategy using a no-rotation strategy, a standard rotation strategy, and a life-degradation-based rotation strategy. Unlike the simple start-stop control strategy, the fuzzy control strategy shows a significant improvement over the no-rotation strategy. The maximum life loss value of each stack is reduced from 34.4 mV to 29.61 mV, and the standard deviation between stacks is also reduced by 12.97%, indicating that the fluctuation in life loss between stacks is reduced. When the life-degradation-based rotation strategy proposed in this work is adopted, the maximum life loss value of the stack is only 67.46 mV, which is 22.12% and 17.56% lower than the 86.62 mV and 81.83 mV under the first two strategies, respectively. The standard deviation under this strategy is only 4.79 mV, far lower than the first two strategies, significantly improving the life balance of the stacks. Figure 12 Figure (b) shows the life loss value of each fuel cell at each moment under the rotation strategy based on life decay.

[0104] Table 8 summarizes the life loss of each stack under different control strategies. Strategy A refers to no rotation, Strategy B refers to a standard rotation strategy, and Strategy C refers to a rotation strategy based on life degradation. The improved fuzzy control strategy, which inherently favors stack consistency, is not affected by the rotation strategy. The average voltage loss reaches 57.01 mV, which is higher than that of the simple start-stop control strategy. This strategy keeps the stack operating point as close to the optimal power as possible, and the life loss rate at optimal power is greater than at the rated power point.

[0105] Although the improved fuzzy control strategy has a higher mean stack loss, it also generates the greatest benefit. The simple start-stop control strategy, on the other hand, has the lowest stack loss and the least benefit. The fuzzy control strategy also has the problem of generating the highest mean stack loss, but its benefit does not exceed that of the improved fuzzy control strategy. Therefore, the simple start-stop control strategy and the improved fuzzy control strategy are clearly superior to the fuzzy control strategy. When considering the consistency of the stack lifespan, the improved fuzzy control strategy is even more superior to the simple start-stop control strategy.

[0106] Table 8 When applying the multi-stack rotation method provided by the present invention considering the life decline of the reversible proton exchange membrane fuel cell, it is not necessary to Figure 1 The steps are executed in the order shown. The specific execution order of the steps can be determined according to needs, and the present invention does not limit this.

[0107] The above is a multi-stack rotation method for considering the life degradation of a reversible proton exchange membrane fuel cell provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding multi-stack rotation device for considering the life degradation of a reversible proton exchange membrane fuel cell, which includes: a determination module for, when power is allocated to multiple stacks of reversible proton exchange membrane fuel cells, optimizing the power of the multiple stacks and determining the optimal power of the stacks with the goal of maximizing the daily revenue of the electric-hydrogen energy system in which the reversible proton exchange membrane fuel cells are located if the rotation time reaches a preset time; A sorting module is used to respectively obtain the life loss of each stack of the reversible proton exchange membrane fuel cell in a historical rotation period, and sort the multiple stacks according to the life loss; the historical rotation period is the rotation period before the current moment; A calculation module is used to calculate the operating power of each stack of the reversible proton exchange membrane fuel cell according to the optimal power of the stack, and obtain the voltage change rate at each operating power; The allocation module is used to allocate working power to each battery stack based on the order of multiple battery stacks and the principle that the battery stack with greater life loss is allocated working power with a smaller voltage change rate.

[0108] Regarding the specific definition of the multi-stack rotation device that takes into account the life decline of reversible proton exchange membrane fuel cells, please refer to the above definition of the multi-stack rotation method that takes into account the life decline of reversible proton exchange membrane fuel cells, which will not be repeated here. The various modules in the above-mentioned multi-stack rotation device that takes into account the life decline of reversible proton exchange membrane fuel cells can be fully or partially implemented by software, hardware and their combination. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0109] The present invention also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 3 A multi-stack rotation method considering the life degradation of reversible proton exchange membrane fuel cells is provided.

[0110] The present invention also provides Figure 13 The structural diagram of the computer equipment shown in FIG. Figure 13 As shown in the figure, at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 3 A multi-stack rotation method considering the life degradation of reversible proton exchange membrane fuel cells is provided.

[0111] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware using a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes in the above-described method embodiments. Any reference to memory, storage, database, or other media used in the various embodiments provided herein may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0112] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present invention.

Claims

1. A multi-stack rotation method considering the life degradation of reversible proton exchange membrane fuel cells, characterized in that: include: In the case of power allocation for multiple stacks of reversible proton exchange membrane fuel cells, if the rotation time reaches a preset time, the power of the multiple stacks is optimized with the goal of maximizing the daily revenue of the electric hydrogen energy system where the reversible proton exchange membrane fuel cells are located to determine the optimal power of the stacks; Obtaining the life loss of each stack of the reversible proton exchange membrane fuel cell in a historical rotation period, and sorting the multiple stacks according to the life loss; the historical rotation period is the rotation period before the current moment; Calculate the operating power of each stack of the reversible proton exchange membrane fuel cell based on the optimal power of the stack, and obtain the voltage change rate at each operating power; Based on the ranking of multiple fuel cells, operating power is allocated to each fuel cell according to the principle that a fuel cell with greater life loss is allocated operating power with a smaller voltage change rate.

2. The method according to claim 1, characterized in that With the goal of maximizing the daily revenue of the electric-hydrogen energy system where the reversible proton exchange membrane fuel cell is located, the power of multiple fuel cell stacks is optimized to determine the optimal power of the fuel cell stacks, including: With the goal of maximizing the daily revenue of the electric-hydrogen energy system, the power of the fuel cell stack is optimized using a particle swarm algorithm, and the optimal solution obtained is determined as the optimal power of the fuel cell stack. The calculation formula for the daily revenue of the electric-hydrogen energy system is: ； in, The daily income of the electric hydrogen energy system; for Operating income at the time; for The operating cost at each moment; ； in, for Total amount of hydrogen produced at the time; is the selling price of hydrogen; ； ； ； ； in, express The acquisition cost at the time, express Operation and maintenance costs at all times, express The penalty cost of the moment, for The total amount of hydrogen purchased at the time, is the purchase price of hydrogen, for The electricity that needs to be purchased at any time, for The electricity price at the time, refer to The total amount of hydrogen produced or consumed at any moment, is the unit price of equipment operation and maintenance, for The total load shedding at the moment, is the load shedding penalty coefficient; The power balance condition in the process of optimizing the power of multi-stack is: ； in, 、 They are Wind and photovoltaic power generation at all times, 、 They are The power generated by electricity or consumed by electrolysis at any moment, express The load power of the system at that moment.

3. The method according to claim 1, characterized in that The life loss of each stack of the reversible proton exchange membrane fuel cell before the historical rotation period is obtained separately, including: For any fuel cell stack, determine the working mode of the fuel cell stack during the historical rotation period; If the working mode of the fuel cell stack is electrolysis mode, the life loss of the fuel cell stack is determined based on the electrolysis voltage loss of the fuel cell stack during the historical rotation period; If the working mode of the fuel cell stack is power generation mode, the life loss of the fuel cell stack is determined based on the output voltage loss of the fuel cell stack during the historical rotation period; If the working mode of the fuel cell stack includes the electrolysis mode and the power generation mode, the life loss of the fuel cell stack is determined based on the sum of the internal electrolysis voltage loss and the output voltage loss of the fuel cell stack during the historical rotation period.

4. The method according to claim 1, wherein Calculate the operating power of each stack of a reversible proton exchange membrane fuel cell, including: The difference between the total input power of all the stacks of the reversible proton exchange membrane fuel cell and the total optimal power is determined as the power difference; The operating power of each fuel cell stack is obtained by performing fuzzy control processing on the power difference.

5. The method according to claim 4, characterized in that By performing fuzzy control on the power difference, the operating power of each fuel cell stack is obtained, including: According to the power difference, the fuzzy input is determined; According to the preset fuzzy control rules, the fuzzy relationship is determined; Determine the fuzzy output according to the fuzzy set and fuzzy relationship corresponding to the fuzzy input; Defuzzify the fuzzy output to obtain the control quantity; The operating power of each fuel cell stack is determined based on the control quantity and the preset fuzzy control strategy.

6. The method according to claim 5, characterized in that According to the control quantity and the preset fuzzy control strategy, the operating power of each fuel cell stack is determined, including: When the control quantity is the first fuzzy output quantity, it is determined that the operating power of all battery stacks is 0; When the control quantity is the second fuzzy output quantity, it is determined that the working power of n stacks is the optimal power, and the working power of one stack is , the remaining battery stacks do not work; , Indicates the total input power, Indicates optimal power; When the control quantity is the third fuzzy output quantity, it is determined that the operating power of all fuel cell stacks is the optimal power; When the control quantity is the fourth fuzzy output quantity, the total working power is used as the constraint condition and the minimum total cost is used as the optimization goal to optimize the working power of each fuel cell stack and obtain the working power of each fuel cell stack; When the controlled quantity is the fifth fuzzy output quantity, it is determined that the operating power of all fuel cell stacks is the rated power.

7. The method according to claim 1, characterized in that Get the voltage change rate at each operating power, including: For any operating power, if the stack operates in electrolysis mode, the voltage change rate under the operating power is determined based on the relationship between the operating power and the rated power; If the fuel cell stack operates in power generation mode, the voltage change rate under the operating power is determined to be a preset value.

8. The method according to claim 7, characterized in that The calculation method of the voltage change rate under the working power corresponding to the electrolysis mode is: ； in, is the voltage change rate under the working power corresponding to the electrolysis mode; Indicates the working power of the battery stack; Indicates the rated power of the battery stack.

9. A multi-stack rotation device considering the life decline of reversible proton exchange membrane fuel cells, characterized in that: include: a determination module for, when power is allocated to multiple stacks of reversible proton exchange membrane fuel cells, optimizing the power of the multiple stacks and determining the optimal power of the stacks with the goal of maximizing the daily revenue of the electric-hydrogen energy system in which the reversible proton exchange membrane fuel cells are located if the rotation time reaches a preset time; A sorting module is used to respectively obtain the life loss of each stack of the reversible proton exchange membrane fuel cell in a historical rotation period, and sort the multiple stacks according to the life loss; the historical rotation period is the rotation period before the current moment; A calculation module is used to calculate the operating power of each stack of the reversible proton exchange membrane fuel cell according to the optimal power of the stack, and obtain the voltage change rate at each operating power; The allocation module is used to allocate working power to each battery stack based on the order of multiple battery stacks and the principle that the battery stack with greater life loss is allocated working power with a smaller voltage change rate.

10. A computer-readable storage medium, characterized in that The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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