A composite hydrogen production system by electrolyzing water

Abstract

The present invention discloses a composite hydrogen production system by water electrolysis, which includes a control module, an execution module, N rectifier transformers, and N electrolytic cell hydrogen production units; the N rectifier transformers correspond to the N electrolytic cell hydrogen production units one by one and are used to convert the current of the power grid into the current of the corresponding electrolytic cell hydrogen production units; the control module is used to obtain the input active power, calculate the optimal start-stop mode of the N electrolytic cell hydrogen production units according to the magnitude of the active power, and send instructions to the execution module to control the execution module to control the start-stop and the output current magnitude of the N rectifier transformers according to the optimal start-stop mode; the N electrolytic cell hydrogen production units include A-type electrolytic cell hydrogen production units and B-type electrolytic cell hydrogen production units of different types from the A-type electrolytic cell hydrogen production units. The present invention can carry out green hydrogen production on the premise of ensuring the full utilization of new energy power or provide power auxiliary services such as peak shaving in the future.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production by new energy power supply, and more specifically, relates to a composite water electrolysis hydrogen production system. Background Art

[0002] Due to the characteristics of volatility and intermittency of new energy power generation systems such as photovoltaic and wind power, it is necessary to discard light and wind when necessary to ensure the safe operation of the power grid. Therefore, the research on reusing the discarded light and wind to improve energy utilization efficiency is particularly important.

[0003] Currently, the problem of accommodating discarded light and wind is being actively explored. The structure of a wind / solar / storage grid-connected microgrid with a hydrogen storage and battery hybrid energy storage system is being studied, and a reference for optimizing the energy storage capacity of the wind / solar / storage microgrid is provided by establishing a microgrid capacity optimization configuration model.

[0004] Among them, hydrogen energy storage technology can achieve long-cycle regulation and is a large-scale energy storage technology with great development potential. Using hydrogen energy storage to improve the accommodation of discarded light and wind has been gradually promoted and studied. On the one hand, based on a comprehensive energy system of large-scale wind power and hydrogen energy storage, considering the uncertainty of wind energy, a day-ahead optimization model can reduce the amount of discarded wind and daily operating costs; on the other hand, starting from the existing wind-solar complementary power generation energy storage control system, a wind-solar complementary power generation energy storage hydrogen production system is established to conduct research on the accommodation of discarded wind and light. However, the above research mainly uses energy storage technology to improve the accommodation level of photovoltaic and wind power, but does not consider problems such as the hydrogen production efficiency and start-stop responsiveness of the electrolyzer when using hydrogen energy storage technology. Summary of the Invention

[0005] Aiming at the above defects or improvement requirements of the existing technology, the present invention provides a composite water electrolysis hydrogen production system, which can realize the local consumption of new energy power, so that the new energy power station has the ability to accommodate discarded wind and light power. When the total power generation in the power system is greater than the total grid load, the output control system of the composite water electrolysis hydrogen production can compensate for the total grid load, so as to carry out green hydrogen production or provide power auxiliary services such as peak shaving in the future on the premise of ensuring the full utilization of new energy power.

[0006] To achieve the above object, the present invention provides a hydrogen production system by electrolyzing water, which includes a control module, an execution module, N rectifier transformers, and N electrolyzer hydrogen production units; the N rectifier transformers correspond to the N electrolyzer hydrogen production units one by one, and are used to convert the current of the power grid into the current of the corresponding electrolyzer hydrogen production unit; the control module is used for calculation and scheduling, specifically including: obtaining the input active power, calculating the optimal start-stop mode of the N electrolyzer hydrogen production units according to the magnitude of the active power, and sending an instruction to the execution module to control the execution module to control the start-stop and the magnitude of the output current of the N rectifier transformers according to the optimal start-stop mode; the N electrolyzer hydrogen production units include A-type electrolyzer hydrogen production units and B-type electrolyzer hydrogen production units, and the types of the A-type electrolyzer hydrogen production units and the B-type electrolyzer hydrogen production units are different.

[0007] In some embodiments, both the A-type electrolyzer hydrogen production unit and the B-type electrolyzer hydrogen production unit are one of an alkaline water electrolysis hydrogen production unit, a pure water proton exchange membrane electrolysis hydrogen production unit, and a solid oxide water electrolysis hydrogen production unit.

[0008] In some embodiments, the control module is used to control the execution module to start the A-type electrolyzer hydrogen production unit and the B-type electrolyzer hydrogen production unit. Among them, the A-type electrolyzer hydrogen production unit preferentially operates at full power to absorb the active power of the power grid, and the B-type electrolyzer hydrogen production unit performs a hot start according to the hydrogen production load of the A-type electrolyzer hydrogen production unit operating at full power; after the B-type electrolyzer hydrogen production unit operates normally after hot start, the control module performs calculation and scheduling again.

[0009] In some embodiments, the control module is used to calculate the optimal start-stop mode of the N electrolyzer hydrogen production units, including:

[0010] Performing a priority ranking on the N electrolyzer hydrogen production units;

[0011] According to the priority ranking and the input active power, distributing the input active power to each electrolyzer hydrogen production unit;

[0012] Constructing a probability matrix, and sampling the start-stop states of the N electrolyzer hydrogen production units according to the probability matrix;

[0013] Judging whether each electrolyzer hydrogen production unit satisfies the constraint conditions of the start-stop time. Otherwise, correcting the start-stop strategy; if so, further judging whether each electrolyzer hydrogen production unit satisfies the constraint condition of not exceeding the power upper limit. If so, iteratively updating the probability matrix. Otherwise, returning to the step of constructing the probability matrix;

[0014] Judging whether the number of iterations reaches the preset maximum number of iterations max_iter. If so, taking the current probability matrix as the optimal probability matrix, and obtaining the optimal start-stop mode of the N electrolyzer hydrogen production units according to this optimal probability matrix.

[0015] In some embodiments, prioritizing the N electrolytic cell hydrogen production units includes:

[0016] Prioritizing the type-A electrolytic cell hydrogen production units;

[0017] Prioritizing the type-B electrolytic cell hydrogen production units;

[0018] Prioritizing the type-A electrolytic cell hydrogen production units and the type-B electrolytic cell hydrogen production units according to the hydrogen production scale.

[0019] In some embodiments, prioritizing the type-A electrolytic cell hydrogen production units includes: obtaining the hydrogen production power consumption Qa of each type-A electrolytic cell hydrogen production unit at the power demand Pmaxa under the maximum hydrogen production condition or the minimum power demand Pmina for maintaining hydrogen production during a certain time period T, and prioritizing the type-A electrolytic cell hydrogen production units according to the hydrogen production power consumption Qa; prioritizing the type-B electrolytic cell hydrogen production units includes: obtaining the hydrogen production power consumption Qb of each type-B electrolytic cell hydrogen production unit at the power demand Pmaxb under the maximum hydrogen production condition or the minimum power demand Pminb for maintaining hydrogen production during a certain time period T, and prioritizing the type-B electrolytic cell hydrogen production units according to the hydrogen production power consumption Qb.

[0020] In some embodiments, distributing the input active power to each electrolytic cell hydrogen production unit according to the prioritization and the input active power includes: when multiple electrolytic cell hydrogen production units are turned on simultaneously and the input active power is less than distributing the input active power to each electrolytic cell hydrogen production unit according to the priority; when multiple electrolytic cell hydrogen production units are turned on simultaneously and the input active power is greater than distributing the input power evenly to each electrolytic cell hydrogen production unit; where t is time, is the power demand of the nth electrolytic cell hydrogen production unit at the maximum hydrogen production condition at the tth moment.

[0021] In some embodiments, constructing the probability matrix includes: constructing a feasible solution Xi according to the response of the electrolytic cell hydrogen production units, where the feasible solution Xi is an N×T matrix, and the elements in the matrix represent the start-stop response states of the N electrolytic cell hydrogen production units during the T time period; constructing a probability matrix based on the feasible solution Xi where, is the dominant feasible solution matrix, obtained by sampling the probability distribution of the feasible solution Xi through the univariate marginal distribution algorithm, where, is the distance vector function of the dominant feasible solution matrix, is the simulated annealing function of the dominant feasible solution matrix, and ω is the weight operator.

[0022] In some embodiments, ω has an initial value ω j , j = 0; The iterative update of the probability matrix includes: updating ω such that and increasing the value of j by 1.

[0023] In some embodiments, the constraints on the start-stop time include: the start time of the electrolyzer should be higher than the minimum start time recorded or calibrated by the system, and the stop time of the electrolyzer should be higher than the minimum stop time recorded or calibrated by the system; The corrected start-stop strategy includes: transforming the start or stop state of the period before the state change and the current period into consistent start-stop through a probability model.

[0024] Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention have the following beneficial effects: Combining the predicted power or curtailed power of photovoltaic and wind farms, etc. as the system input power with the real-time output of the electrolyzer, optimizing the start-stop response of the composite multi-electrolyzer based on the optimal efficiency, and being able to select the electrolyzer priority response control according to the input situation of the active power for the power consumption of photovoltaic and wind power, etc. At the same time, the present invention can also solve the problem that the uniformity of the electrolyzer cannot be maintained at a high level during long-term operation, and further improve the comprehensive utilization efficiency of the composite multi-electrolyzer hydrogen production system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of the composite water electrolysis hydrogen production system according to an embodiment of the present invention;

[0026] Figure 2 is a schematic structural diagram of the composite water electrolysis hydrogen production system according to an embodiment of the present invention for the utilization of curtailed power in a wind farm;

[0027] Figure 3 is a schematic structural diagram of the composite water electrolysis hydrogen production system according to an embodiment of the present invention for the predicted power generation of a photovoltaic power station;

[0028] Figure 4 is a flowchart of the method for controlling the control module of the composite water electrolysis hydrogen production system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and the description are considered to be exemplary in nature and not restrictive.

[0030] As Figure 1As shown in the figure, the composite water electrolysis hydrogen production system according to the embodiment of the present invention includes: a control module, an execution module, N rectifier transformers, N electrolyzer hydrogen production units, a hydrogen purification system, and a power supply module. Among them, the control module is used for calculation and scheduling, including: obtaining the input active power, calculating the optimal start-stop mode of the N electrolyzer hydrogen production units according to the magnitude of the active power, and sending instructions to the execution module to control the execution module to execute the corresponding start-stop strategy, that is, controlling the start-stop and the magnitude of the output current of the N rectifier transformers according to the optimal start-stop mode of the N electrolyzer hydrogen production units. Specifically, N≥2 and N is an integer. The N rectifier transformers are respectively the first rectifier transformer to the Nth rectifier transformer, and the N electrolyzer hydrogen production units are respectively the first electrolyzer hydrogen production unit to the Nth electrolyzer hydrogen production unit. The N rectifier transformers correspond one-to-one with the N electrolyzer hydrogen production units, and are used to convert the current of the power grid into the current suitable for the corresponding electrolyzer hydrogen production unit.

[0031] The N electrolyzer hydrogen production units include electrolyzer hydrogen production units with two different water electrolysis hydrogen production processes, which are respectively represented as type A electrolyzer hydrogen production units and type B electrolyzer hydrogen production units. In some embodiments, both the type A electrolyzer hydrogen production unit and the type B electrolyzer hydrogen production unit are one of an alkaline water electrolysis cell for hydrogen production, a pure water proton exchange membrane electrolysis cell for hydrogen production, and a solid oxide water electrolysis cell for hydrogen production, and the type of the type B electrolyzer hydrogen production unit is different from that of the type A electrolyzer hydrogen production unit. In some embodiments, the electrolyzer hydrogen production unit includes an electrolyzer and its supporting water supply system and process devices such as steam-water separation.

[0032] The hydrogen purification system is used to collect the hydrogen generated by the N electrolyzer hydrogen production units through a hydrogen pipeline and a converging system and perform drying treatment. The power supply module is used to provide power for the started electrolyzer hydrogen production units. For example, it provides power for the water supply system, steam-water separation device, and valve instruments supporting the electrolyzer. In some embodiments, the power supply module is a low-voltage power distribution device.

[0033] Specifically, in the initial startup state of the cold startup of the composite water electrolysis hydrogen production system, the control module controls the execution module to start the type A electrolyzer hydrogen production units and the type B electrolyzer hydrogen production units in the N electrolyzer hydrogen production units at the same time. Among them, the type A electrolyzer hydrogen production units give priority to full-power operation to consume the active power of the power grid, and the type B electrolyzer hydrogen production units perform hot startup according to the hydrogen production load of the type A electrolyzer hydrogen production units running at full power. After the type B electrolyzer hydrogen production units are normally running after hot startup, the control module performs calculation and scheduling again.

[0034] Specifically, the control module can receive the active power data of the surplus power obtained from the curtailment measurement of wind and light power or the active power data of the planned output obtained from power prediction. In some embodiments, the control module can also receive the hydrogen production energy efficiency of each electrolytic cell hydrogen production unit to control the start-stop sequence of each electrolytic cell hydrogen production unit under various working conditions.

[0035] Specifically, while sending instructions to the execution module, the control module controls the power supply module to supply power to the started electrolytic cell hydrogen production units according to the start-stop strategies of the N rectifier transformers.

[0036] Figure 2 It is a schematic structural diagram of the composite water electrolysis hydrogen production system of the embodiment of the present invention for the utilization of abandoned electricity in a wind farm. As Figure 2 shown, the composite water electrolysis hydrogen production system of the embodiment of the present invention includes a control module, an execution module, N rectifier transformers, N electrolytic cell hydrogen production units, a hydrogen purification system, and a power supply module. Among them, the N electrolytic cell hydrogen production units are composed of N1 type A electrolytic cell hydrogen production units and N2 type B electrolytic cell hydrogen production units. Both N1 and N2 are integers and are greater than or equal to 1, and N = N1 + N2. The N rectifier transformers correspond to the N electrolytic cell hydrogen production units one by one, and are used to convert the current of the power grid into a current suitable for the corresponding electrolytic cell hydrogen production unit.

[0037] Specifically, the type A electrolytic cell hydrogen production unit is a pure water proton exchange membrane electrolytic cell hydrogen production unit, including a pure water proton exchange membrane electrolytic cell and its supporting water supply system and process devices such as steam-water separation. The type B electrolytic cell hydrogen production unit is an alkaline water electrolysis cell hydrogen production unit, including an alkaline water electrolysis cell and its supporting water supply system and process devices such as steam-water separation.

[0038] The curtailment wind power measurement module ensures that the difference between the measured curtailment wind power active power and the active power consumed by the composite water electrolysis hydrogen production is less than 10 - 20% through the short-term power prediction system and in combination with the ultra-short-term total power grid load and wind farm power generation.

[0039] Specifically, under the condition that the static investment and actual situation permit, the quantity ratio of the type A electrolytic cell to the type B electrolytic cell of the composite electrolytic cell is 1:5 - 1:1. In the initial startup state of the cold startup of the composite water electrolysis hydrogen production system, the control module controls the execution module to start the type A electrolytic cell hydrogen production units and the type B electrolytic cell hydrogen production units in the N electrolytic cell hydrogen production units simultaneously. Among them, the type A electrolytic cell hydrogen production units give priority to full-power operation to consume the active power of the power grid, and the type B electrolytic cell hydrogen production units are thermally started according to the hydrogen production load of the full-power operation of the type A electrolytic cell hydrogen production units. After the type B electrolytic cell hydrogen production units are normally operating in thermal startup, the control module calculates and schedules again to control the start-stop actions and hydrogen production loads of the type A electrolytic cell hydrogen production units and the type B electrolytic cell hydrogen production units.

[0040] Figure 3 This is a schematic structural diagram of the composite water electrolysis hydrogen production system of the embodiment of the present invention for photovoltaic power station predicted power generation. As Figure 3 shown, N electrolyzer hydrogen production units are composed of N3 type A electrolyzer hydrogen production units and N4 type B electrolyzer hydrogen production units. Both N3 and N4 are integers and are greater than or equal to 1, and N = N3 + N4. N rectifier transformers correspond one-to-one with N electrolyzer hydrogen production units, and are used to convert the current of the power grid into the appropriate current for the corresponding electrolyzer hydrogen production unit. The type A electrolyzer hydrogen production unit is a pure water proton exchange membrane electrolyzer hydrogen production unit, including a pure water proton exchange membrane electrolyzer and its supporting water supply system and process devices such as steam-water separation. The type B electrolyzer hydrogen production unit is an alkaline water electrolysis hydrogen production unit, including an alkaline water electrolyzer and its supporting water supply system and process devices such as steam-water separation.

[0041] For the off-grid or directly-supplied photovoltaic power station in this embodiment, its photovoltaic power prediction module conducts simulation prediction with the ultra-short-term power prediction system through the photovoltaic output polarization curve generated by the day-ahead dispatch, ensuring that the difference between the measured active power of the photovoltaic power and the active power consumed by the composite water electrolysis hydrogen production is less than 5-20%.

[0042] Specifically, under the condition that the static investment and actual situation permit, the quantity ratio of the type A electrolyzer to the type B electrolyzer of the composite electrolyzer is 1:5 to 1:1. In the initial startup state of the cold startup of the composite water electrolysis hydrogen production system, the control module controls the execution module to start the type A electrolyzer hydrogen production unit and the type B electrolyzer hydrogen production unit in the N electrolyzer hydrogen production units at the same time. Among them, the type A electrolyzer hydrogen production unit preferentially operates at full power to consume the active power of the power grid, and the type B electrolyzer hydrogen production unit conducts hot startup according to the hydrogen production load of the type A electrolyzer hydrogen production unit operating at full power. After the type B electrolyzer hydrogen production unit operates normally after hot startup, the control module calculates and schedules again to control the start-stop actions and hydrogen production loads of the type A electrolyzer hydrogen production unit and the type B electrolyzer hydrogen production unit.

[0043] As Figure 4 shown, the steps executed by the control module of the composite water electrolysis hydrogen production system of the embodiment of the present invention include:

[0044] S1: Control the execution module to start the composite water electrolysis hydrogen production system, and supply power to the N electrolyzer hydrogen production units through the rectifier transformer.

[0045] S2: Sort the N electrolyzer hydrogen production units by priority, and this priority is the priority of allocating input power to each electrolyzer hydrogen production unit.

[0046] In some embodiments, performing priority ranking specifically includes: performing priority ranking on the hydrogen production units of type A electrolyzers; performing priority ranking on the hydrogen production units of type B electrolyzers; and performing priority ranking on the hydrogen production units of type A electrolyzers and type B electrolyzers according to the hydrogen production scale.

[0047] In some embodiments, performing priority ranking on the hydrogen production units of type A electrolyzers includes: obtaining the hydrogen production power consumption Qa of each hydrogen production unit of type A electrolyzers at the power demand Pmaxa under the maximum hydrogen production condition or the minimum power demand Pmina for maintaining hydrogen production during a certain time period T, and performing priority ranking on the hydrogen production units of type A electrolyzers according to the hydrogen production power consumption Qa. For example, performing priority ranking in ascending order of the Qa value, that is, the lower the Qa value, the higher the priority ranking.

[0048] In some embodiments, the hydrogen production unit of type A electrolyzers with the lowest Qa value has the first priority. As the Qa value increases, the corresponding hydrogen production units of type A electrolyzers sequentially have the second priority, the third priority, and so on.

[0049] Similarly, in some embodiments, performing priority ranking on the hydrogen production units of type B electrolyzers includes: obtaining the hydrogen production power consumption Qb of each hydrogen production unit of type B electrolyzers at the power demand Pmaxb under the maximum hydrogen production condition or the minimum power demand Pminb for maintaining hydrogen production during a certain time period T, and performing priority ranking on the hydrogen production units of type B electrolyzers according to the hydrogen production power consumption Qb. For example, performing priority ranking in ascending order of the Qb value, that is, the lower the Qb value, the higher the priority ranking.

[0050] In some embodiments, the hydrogen production unit of type B electrolyzers with the lowest Qb value has the first priority. As the Qb value increases, the corresponding hydrogen production units of type B electrolyzers sequentially have the second priority, the third priority, and so on.

[0051] In some embodiments, T is the daily or weekly operating duration of the hydrogen production units of type A electrolyzers and type B electrolyzers, in hours.

[0052] In some embodiments, the hydrogen production unit of type A electrolyzers is one of an alkaline water electrolysis hydrogen production unit, a pure water proton exchange membrane electrolysis hydrogen production unit, and a solid oxide water electrolysis hydrogen production unit.

[0053] In some embodiments, the hydrogen production unit of type B electrolyzers is one of an alkaline water electrolysis hydrogen production unit, a pure water proton exchange membrane electrolysis hydrogen production unit, and a solid oxide water electrolysis hydrogen production unit. The type of the hydrogen production unit of type B electrolyzers is different from that of the hydrogen production unit of type A electrolyzers.

[0054] S3: According to the priority ranking of the N electrolyzer hydrogen production units and the active power input to the composite water electrolysis hydrogen production system, allocate the input active power to each electrolyzer hydrogen production unit.

[0055] In some embodiments, step S3 further includes: calculating the comprehensive energy efficiency θ of the N electrolyzer hydrogen production units.

[0056] Specifically, when multiple electrolyzer hydrogen production units are started simultaneously and the input active power is less than allocate the input active power to each electrolyzer hydrogen production unit according to the priority. The comprehensive energy efficiency of the N electrolyzer hydrogen production units where t is time, is the power demand of the nth electrolyzer hydrogen production unit at the maximum hydrogen production condition at the t-th moment, is the start-stop state of the nth electrolyzer hydrogen production unit at the t-th moment (the value is 1 when starting and 0 when stopping), and N is the total number of electrolyzer hydrogen production units, where, is the input active power of the nth electrolyzer hydrogen production unit at the t-th moment, c t is the unit price of hydrogen at the t-th moment, T t is the operating time of hydrogen production of the composite water electrolysis hydrogen production system at the t-th moment, is the hydrogen production amount of the nth electrolyzer hydrogen production unit at the t-th moment.

[0057] Through "priority allocation", with other constraint conditions being the same, under the condition of a certain power consumption of the whole system, the hydrogen production amount is larger, thereby improving the comprehensive energy efficiency of the system.

[0058] Specifically, when multiple electrolyzer hydrogen production units are started simultaneously and the input active power is greater than allocate the input power evenly to each electrolyzer hydrogen production unit. The comprehensive energy efficiency of the N electrolyzer hydrogen production units where μ is the usage cost factor of the system, representing the operating cost and time cost of the electrolyzer hydrogen production unit. The larger the value, the better the state of the hydrogen production unit. In some embodiments, the value of μ is 1 / (operating life of the hydrogen production unit * operating cost of the hydrogen production unit during the life period). where, P t is the total input active power of the N electrolyzer hydrogen production units at the t-th moment, and its expression is Q t is the total hydrogen production amount of the N electrolyzer hydrogen production units at the t-th moment, N t is the number of started hydrogen production units at the t-th moment.

[0059] S4: Initialize the weight operator ω such that ω = ω j, j = 0; that is, ω has a preset starting value ω0. In some embodiments, ω0 = 0.69 - 0.99, for example, ω0 = 0.9;

[0060] S5: Use a weight operator to construct a probability matrix P, and sample the start-stop states of each electrolyzer hydrogen production unit in the composite water electrolysis hydrogen production system according to the probability matrix P;

[0061] Specifically, according to the response of the electrolyzer hydrogen production unit, a feasible solution Xi (an N×T matrix) is constructed. The value of each element in the matrix is 1 (start state) or 0 (stop state), representing the start-stop response states of N electrolyzer hydrogen production units in the T time period. Based on the feasible solution Xi, a probability matrix is constructed Among them, is the dominant feasible solution matrix, which is obtained by sampling the probability distribution of the feasible solution Xi through the univariate marginal distribution algorithm. Among them, is the distance vector function of the dominant feasible solution matrix, is the simulated annealing function of the dominant feasible solution matrix.

[0062] S6: Judge whether each electrolyzer hydrogen production unit satisfies the constraint conditions of start-stop time. If there is an electrolyzer hydrogen production unit that does not satisfy the constraint conditions, enter S7; if all electrolyzer hydrogen production units satisfy the constraint conditions, enter S8;

[0063] The constraint conditions of start-stop time include: (1) The start time of the electrolyzer should be higher than the minimum start time recorded (or operationally calibrated) by the system; (2) The stop time of the electrolyzer should be higher than the minimum stop time recorded (or operationally calibrated) by the system.

[0064] S7: Modify the start-stop strategy;

[0065] Specifically, in the system startup stage: Since there are historical feasible solutions and this part cannot be changed, the start-stop states at the beginning are directly copied from the historical states. The object of copying is the electrolyzer hydrogen production unit that needs to correct the historical state; in the startup stage of the electrolyzer hydrogen production unit: For each electrolyzer hydrogen production unit, traverse the start-stop states in the total time period. When a state change is encountered, if the start-stop time constraint is not satisfied, the start or stop states of the time period before the state change and the current time period are changed to be consistent in start-stop through a probability model.

[0066] S8: Judge whether each electrolyzer hydrogen production unit satisfies the constraint condition of not exceeding the power upper limit. If there is an electrolyzer hydrogen production unit that does not satisfy the constraint condition, enter S5; if all electrolyzer hydrogen production units satisfy the constraint condition, enter S9;

[0067] In some embodiments, the power upper limit is set artificially and is lower than the maximum load power of each electrolyzer hydrogen production unit itself.

[0068] S9: Update the weight operator such that Update the probability matrix where max_iter is the preset maximum number of iterations, increase the value of j by 1, and then enter S10;

[0069] S10: Determine whether the value of j has reached the maximum number of iterations. If not, enter S5. If so, consider the current probability matrix as the optimal probability matrix and enter S11;

[0070] S11: Control the start and stop of the corresponding electrolyzer hydrogen production unit of the execution module according to the element values of the optimal solution Xi corresponding to the optimal probability matrix.

[0071] The present invention combines the predicted power or curtailed power of photovoltaic and wind power stations, etc. as the system input power with the real-time output of the electrolyzer, and optimizes the start-stop response of the composite multi-electrolyzer based on the optimal efficiency, so as to select the electrolyzer priority response control according to the input situation of the active power for the power consumption of photovoltaic and wind power, etc. At the same time, the present invention can also solve the problem that the uniformity of the electrolyzer cannot be maintained at a high level during long-term operation, and further improve the comprehensive utilization efficiency of the composite multi-electrolyzer hydrogen production system.

[0072] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without conflict, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples.

[0073] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0074] Any process or method description represented in a flowchart or otherwise described herein can be understood to represent a module, segment, or portion of code including one or more (two or more) executable instructions for implementing a specific logical function or process. And the scope of the preferred embodiments of the present application includes additional implementations, where functions may be performed in a substantially simultaneous manner or in a reverse order according to the functions involved, rather than in the order shown or discussed.

[0075] The logic and / or steps represented in a flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing a logical function, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in conjunction with these instruction execution systems, apparatuses, or devices.

[0076] It should be understood that each part of the present application can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. All or part of the steps of the method in the above embodiments can be completed by instructing relevant hardware through a program, and this program can be stored in a computer-readable storage medium. When this program is executed, it includes one or a combination of the steps of the method embodiments.

[0077] In addition, in each embodiment of the present application, the functional units can be integrated into a processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. When the above integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. This storage medium can be a read-only memory, a magnetic disk, an optical disc, etc.

[0078] As described above, only the specific embodiments of the present application are provided, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application can easily think of various changes or substitutions, and these should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A hydrogen production system by water electrolysis, characterized in that, It includes a control module, an execution module, N rectifier transformers and N electrolytic cell hydrogen production units; the N rectifier transformers correspond to the N electrolytic cell hydrogen production units one by one and are used to convert the current of the power grid into the current of the corresponding electrolytic cell hydrogen production unit; The control module is used for calculation and scheduling, specifically including: obtaining the input active power, calculating the optimal start-stop mode of the N electrolytic cell hydrogen production units according to the magnitude of the active power, and sending instructions to the execution module to control the execution module to control the start-stop and the magnitude of the output current of the N rectifier transformers according to the optimal start-stop mode; the N electrolytic cell hydrogen production units include type A electrolytic cell hydrogen production units and type B electrolytic cell hydrogen production units, and the types of the type A electrolytic cell hydrogen production units and the type B electrolytic cell hydrogen production units are different; Among them, the control module is used for calculating the optimal start-stop mode of the N electrolytic cell hydrogen production units, including: Performing priority sorting on the N electrolytic cell hydrogen production units; Allocating the input active power to each electrolytic cell hydrogen production unit according to the priority sorting and the input active power; Constructing a probability matrix and sampling the start-stop states of the N electrolytic cell hydrogen production units according to the probability matrix; Judging whether each electrolytic cell hydrogen production unit satisfies the constraint condition of the start-stop time, otherwise correcting the start-stop strategy; if so, further judging whether each electrolytic cell hydrogen production unit satisfies the constraint condition of not exceeding the power upper limit, if so, iteratively updating the probability matrix, otherwise returning to the step of constructing the probability matrix; Judging whether the number of iterations reaches the preset maximum number of iterations max_iter, if so, taking the current probability matrix as the optimal probability matrix, and obtaining the optimal start-stop mode of the N electrolytic cell hydrogen production units according to this optimal probability matrix; Among them, performing priority sorting on the N electrolytic cell hydrogen production units includes: Performing priority sorting on the type A electrolytic cell hydrogen production units; Performing priority sorting on the type B electrolytic cell hydrogen production units; Performing priority sorting on the type A electrolytic cell hydrogen production units and the type B electrolytic cell hydrogen production units according to the hydrogen production scale; Among them, performing priority sorting on the type A electrolytic cell hydrogen production units includes: obtaining the hydrogen production power consumption Qa of each type A electrolytic cell hydrogen production unit under the power demand Pmaxa in the maximum hydrogen production condition or the minimum power demand Pmina for maintaining hydrogen production in a certain time period T, and performing priority sorting on the type A electrolytic cell hydrogen production units according to the hydrogen production power consumption Qa; performing priority sorting on the type B electrolytic cell hydrogen production units includes: obtaining the hydrogen production power consumption Qb of each type B electrolytic cell hydrogen production unit under the power demand Pmaxb in the maximum hydrogen production condition or the minimum power demand Pminb for maintaining hydrogen production in a certain time period T, and performing priority sorting on the type B electrolytic cell hydrogen production units according to the hydrogen production power consumption Qb; Among them, allocating the input active power to each electrolytic cell hydrogen production unit according to the priority ranking and the input active power includes: when multiple electrolytic cell hydrogen production units are started simultaneously and the input active power is less than , allocating the input active power to each electrolytic cell hydrogen production unit according to the priority; when multiple electrolytic cell hydrogen production units are started simultaneously and the input active power is greater than , evenly allocating the input power to each electrolytic cell hydrogen production unit; where t is time, is the power demand of the nth electrolytic cell hydrogen production unit at the maximum hydrogen production condition at the tth moment.

2. The hydrogen production system by water electrolysis according to claim 1, characterized in that, Both the type A electrolytic cell hydrogen production units and the type B electrolytic cell hydrogen production units are one of an alkaline water electrolysis cell hydrogen production unit, a pure water proton exchange membrane electrolysis cell hydrogen production unit and a solid oxide water electrolysis cell hydrogen production unit.

3. The water electrolysis hydrogen production system according to claim 1, characterized in that, The control module is used to control the execution module to start the Type-A electrolytic cell hydrogen production unit and the Type-B electrolytic cell hydrogen production unit. Among them, the Type-A electrolytic cell hydrogen production unit preferentially operates at full power to absorb the active power of the power grid, and the Type-B electrolytic cell hydrogen production unit is thermally started according to the hydrogen production load when the Type-A electrolytic cell hydrogen production unit operates at full power; after the Type-B electrolytic cell hydrogen production unit is thermally started and operates normally, the control module performs calculation and scheduling again.

4. The hydrogen production system by electrolyzing water according to claim 1, characterized in that, Constructing a probability matrix includes: constructing a feasible solution \(X_i\) according to the response of the electrolyzer hydrogen production unit, where the feasible solution \(X_i\) is an \(N\times T\) matrix, and the elements in the matrix represent the start-stop response status of the \(N\) electrolyzer hydrogen production units in the \(T\) time period; constructing a probability matrix based on the feasible solution \(X_i\). Among them, is the dominant feasible solution matrix, which is obtained by sampling the probability distribution of the feasible solution \(X_i\) through the univariate marginal distribution algorithm. Among them, is the distance vector function of the dominant feasible solution matrix. is the simulated annealing function of the dominant feasible solution matrix, and \(\omega\) is the weight operator.

5. The water electrolysis hydrogen production system according to claim 4, wherein ω has an initial value of ω j , j = 0; the iterative update of the probability matrix includes: updating ω such that and increasing the value of j by 1.

6. The hydrogen production system by electrolyzing water according to claim 1, characterized in that, The constraint conditions for start-stop times include: the start time of the electrolytic cell should be higher than the minimum start time recorded or calibrated by the system, and the stop time of the electrolytic cell should be higher than the minimum stop time recorded or calibrated by the system; the modified start-stop strategy includes: transforming the start or stop states of the period before the state change and the current period into consistent start-stop through a probability model.

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