Renewable energy-connected water electrolysis system, and control device and control method for a renewable energy-connected water electrolysis system

Abstract

Even when output restrictions are imposed on renewable energy generation systems, the operating rates of both renewable energy generation systems and water electrolysis systems will be appropriately ensured. [Solution] The control device 19 of the renewable energy grid-connected water electrolysis system 11 includes an acquisition unit 21 that acquires an output power limit command value R_Grid and an electrolysis power upper limit value P_UP, respectively; a calculation unit 23 that calculates a power generation threshold R_SUM, which is the sum of the output power limit command value R_Grid and the electrolysis power upper limit value P_UP; a setting unit 25 that sets the power generation upper limit value R_UP related to the renewable energy power generation system 13 to be less than or equal to the power generation threshold R_SUM calculated by the calculation unit 23; and a coordinated control unit 27 that coordinates the output control of the power generation related to the renewable energy power generation system 13 and the electrolysis power control related to the water electrolysis system 17 so that the power generation related to the renewable energy power generation system 13 does not exceed the power generation upper limit value R_UP.

Description

Technical Field

[0001] The present invention relates to a renewable energy-linked water electrolysis system, as well as a control device and a control method for the renewable energy-linked water electrolysis system.

Background Art

[0002] Hydrogen is a clean energy that does not emit carbon dioxide during combustion, unlike fossil fuels that emit carbon dioxide during combustion. Hydrogen is attracting attention as one of the clean energies for achieving carbon neutrality, and technological development related to the production, transportation, and utilization of hydrogen is underway.

[0003] Hydrogen can be produced anywhere by electrolyzing water. Therefore, a water electrolysis system that produces hydrogen by water electrolysis has attracted attention as a means to reduce the amount of imported energy and improve the energy self-sufficiency rate. Large-scale future introduction of water electrolysis systems is planned mainly in Europe.

[0004] Regarding the electric power used for hydrogen production by a water electrolysis system, efforts are also being made to produce green hydrogen by utilizing the output of a power generation device using renewable energy (referred to as a "renewable energy power generation system"). For example, a water electrolysis system is connected to a connection point where renewable energy (sometimes abbreviated as "renewable energy") is connected to the grid, or in the vicinity thereof, and the water electrolysis system connected to the renewable energy power generation system consumes the generated electric power from the renewable energy to produce hydrogen. For the sake of convenience of explanation, a system with such a configuration is referred to as a renewable energy-linked water electrolysis system.

[0005] Patent Document 1 discloses an invention related to an operation method of a renewable energy-linked water electrolysis system. The renewable energy interconnected water electrolysis system described in Patent Document 1 is a renewable energy output system having a renewable energy power generation facility and a variable power utilization device, and capable of supplying surplus output to an external power grid. The system includes a control unit that acquires power generation information from the renewable energy power generation facility and controls the amount of power supplied that is consumed by the variable power utilization device from the power generation. The control unit uses an output Pf obtained by smoothing the time-series output P of the renewable energy power generation facility with a predetermined time constant, and a predetermined function F with Pf as a variable, to calculate the electrolysis power Pe of the variable power utilization device from the formula Pe = P - [Pf - F(Pf)] (where the maximum value of F(Pf) = the upper limit electrolysis power of the variable power utilization device), and controls the system to supply the calculated electrolysis power to the variable power utilization device and supply the surplus output to an external power grid. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-226238 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Patent Document 1 discloses a method for operating a water electrolysis system when no output restrictions are imposed on the renewable energy power generation system. However, with the widespread adoption of water electrolysis systems, it is anticipated that scenarios in which output restrictions are imposed on renewable energy power generation systems will become more frequent. Consequently, when operating a water electrolysis system using electricity generated by a renewable energy power generation system, if output restrictions are imposed on the renewable energy power generation system, there is a risk that the water electrolysis system may not be able to be operated properly.

[0008] The present invention has been made to solve the above-mentioned problems, and aims to provide a renewable energy-connected water electrolysis system that can be properly operated even when the renewable energy power generation system is subject to output limitations when operating the water electrolysis system using electricity generated from a renewable energy power generation system, as well as a control device and control method for the renewable energy-connected water electrolysis system. Issues, configurations, and effects other than those mentioned above will be described in detail in the following appropriate method. [Means for solving the problem]

[0009] To solve the above problems, the renewable energy-linked water electrolysis system according to the present invention A renewable energy interconnected water electrolysis system comprising: a renewable energy power generation system that outputs power generated using renewable energy to the grid at least; and a water electrolysis system connected to the grid via a common interconnection point for the renewable energy power generation system, which receives the output of the power generated and produces hydrogen by electrolyzing water, wherein The system includes a control device that controls the output of the generated power related to the renewable energy power generation system and the electrolytic power related to the water electrolysis system, The control device is An acquisition unit that acquires the output power limit command value for the renewable energy generation system and the electrolysis power upper limit value, which is the upper limit of the electrolysis power for the water electrolysis system, A calculation unit calculates a power generation threshold value which is the sum of the output power limit command value and the electrolytic power upper limit value acquired by the acquisition unit, A setting unit sets the upper limit of power generation, which is the upper limit of power generation related to the renewable energy power generation system, to be less than or equal to the power generation threshold calculated by the calculation unit, A coordinated control unit that coordinates the output control of the renewable energy generation system and the electrolysis power control of the water electrolysis system so that the generated power of the renewable energy generation system does not exceed the upper limit of generated power set by the setting unit, Its most notable feature is that it is configured to include the following: [Effects of the Invention]

[0010] According to the present invention, when operating a water electrolysis system using the power output of a renewable energy generation system, even if the renewable energy generation system is subject to output restrictions, the operating rate of both the renewable energy generation system and the water electrolysis system can be appropriately ensured. Issues, configurations, and effects other than those mentioned above will be described in detail in the following appropriate method. [Brief explanation of the drawing]

[0011] [Figure 1A] This block diagram shows a schematic configuration of a renewable energy-connected water electrolysis system according to an embodiment of the present invention. [Figure 1B] This block diagram shows a first example of setting the upper limit of the output value by the setting unit belonging to the water electrolysis system in a renewable energy-connected water electrolysis system. [Figure 1C] This block diagram shows a second example of setting the upper limit of the output value by the setting unit belonging to the water electrolysis system in a renewable energy-connected water electrolysis system. [Figure 2A] This is a schematic diagram of the water electrolysis system installed in a renewable energy grid-connected water electrolysis system. [Figure 2B] This is a schematic diagram of the water electrolysis device included in a water electrolysis system. [Figure 2C] This is a schematic diagram of the pure water adjustment device included in a water electrolysis system. [Figure 3] This is a flowchart illustrating the operation of the control device for a renewable energy-linked water electrolysis system. [Figure 4] This is a time chart diagram used to explain the operation of the control device for a renewable energy-linked water electrolysis system. [Figure 5] This is a time chart diagram used to explain the operation of the first operating mode of the control device for a renewable energy-linked water electrolysis system. [Figure 6] This is a time chart diagram used to explain the operation of the second operating mode of the control device for a renewable energy-linked water electrolysis system. [Figure 7] This is a time chart diagram used to explain the operation of the third operating mode of the control device for a renewable energy-linked water electrolysis system. [Figure 8] A time chart for explaining the operation when offsetting the electrolysis power of the electrolysis system included in the renewable energy-linked electrolysis system. [Figure 9] A time chart for explaining the operation of the normal operation mode related to the control device of the renewable energy-linked electrolysis system.

Embodiment for Carrying Out the Invention

[0012] The renewable energy-linked electrolysis system according to an embodiment of the present invention, as well as the control device and control method of the renewable energy-linked electrolysis system, will be described in detail with reference to appropriate drawings as appropriate. In the figures shown below, in principle, common reference numerals are assigned to members having common functions or members having corresponding functions to each other, and duplicate descriptions are omitted. The sizes and shapes of the members may be schematically represented in a deformed or exaggerated manner for the convenience of explanation.

[0013] 〔Schematic Configuration of Renewable Energy-Linked Electrolysis System 11〕 The schematic configuration of the renewable energy-linked electrolysis system 11 according to an embodiment of the present invention will be described with appropriate reference to FIGS. 1A to 1C. FIG. 1A is a block diagram showing the schematic configuration of the renewable energy-linked electrolysis system 11 according to an embodiment of the present invention. FIG. 1B is a block diagram showing an example of setting the output upper limit value by the setting unit 25 belonging to the electrolysis system 17 provided in the renewable energy-linked electrolysis system 11. FIG. 1C is a block diagram showing an example of setting the output upper limit value by the setting unit 25 belonging to the electrolysis system 17 provided in the renewable energy-linked electrolysis system 11.

[0014] As shown in Figure 1A, the renewable energy grid-connected water electrolysis system 11 comprises a renewable energy power generation system 13 that outputs generated electricity generated using renewable energy such as solar, wind, and hydropower to at least the grid 15; a water electrolysis system 17 connected to the grid 15 via a common interconnection point 16 for the renewable energy power generation system 13, which produces hydrogen by electrolyzing water in response to the output of the generated electricity; and a control device 19 that coordinates the output control of the generated electricity related to the renewable energy power generation system 13 and the electrolysis power control related to the water electrolysis system 17. The grid 15 is, for example, a power grid such as the commercial power grid.

[0015] The renewable energy generation system 13 and the water electrolysis system 17 are interconnected via a communication medium 18 (whether wired or wireless). Each of the renewable energy generation system 13 and the water electrolysis system 17 is configured to exchange various information, including the power generation command value for the renewable energy generation system 13 and the electrolysis power command value and electrolysis power rating value for the water electrolysis system 17, via the communication medium 18 and the control device 19, respectively.

[0016] In the renewable energy interconnected water electrolysis system 11 according to the present invention, part or all of the power generated by the renewable energy power generation system 13 is consumed by the electrolysis power generated by the water electrolysis system 17. When such power generation is consumed and a surplus differential power (power generation - electrolysis power) is generated, the system is configured to transmit that differential power to the grid 15.

[0017] The renewable energy generation system 13 comprises a renewable energy generator (not shown) that generates electricity using renewable energy, and a renewable energy control device (not shown) that controls the output of the generated electricity from the renewable energy generator. The renewable energy generation system 13 is configured to output the generated electricity generated using renewable energy to the grid 15 and the water electrolysis system 17 via the connection point 16.

[0018] As a premise, in the renewable energy grid-connected water electrolysis system 11 according to the embodiment of the present invention, it is assumed that, for example, the output of the power generated by the renewable energy power generation system 13 is restricted based on the request of the grid operator operating the grid 15, the operating status of the water electrolysis system 17, etc. Specifically, it is assumed that an output power restriction command value R_Grid has been issued to the renewable energy power generation system 13, indicating that the upper limit of the output should be restricted. In cases where output restrictions are imposed on the renewable energy generation system 13, in order to ensure the stable operation of the grid 15, the amount of electricity supplied to the grid 15 from the renewable energy generation system 13 is limited to less than the output power restriction command value R_Grid.

[0019] Furthermore, the renewable energy generation system 13 is capable of outputting power exceeding the output power limit command value R_Grid when the water electrolysis system 17 is in an operational state. In this case, as described above, part or all of the power generated by the renewable energy power generation system 13 is consumed by the electrolytic power of the water electrolysis system 17, and the electrolytic power consumed by the water electrolysis system 17 is set based on a predetermined electrolytic power upper limit value P_UP (details will be described later). As a result, the transmission power value R_SY, which is the differential power output from the renewable energy interconnected water electrolysis system 11 to the grid 15, can be accurately limited to less than the output power limit command value R_Grid.

[0020] [Outline configuration of water electrolysis system 17] The schematic configuration of the water electrolysis system 17, which constitutes a part of the renewable energy-linked water electrolysis system 11 according to an embodiment of the present invention, will be described with reference to Figures 2A to 2C as appropriate. Figure 2A is a schematic diagram of the water electrolysis system 17 provided in the renewable energy grid-connected water electrolysis system 11. Figure 2B is a schematic diagram of the water electrolysis device 31 provided in the water electrolysis system 17. Figure 2C is a schematic diagram of the pure water adjustment device 33 provided in the water electrolysis system 17.

[0021] As shown in Figure 2A, the water electrolysis system 17 is comprised of a water electrolyzer 31, a pure water adjustment device 33, a power converter 35, an electrolysis control device 37, a switch 39, and a transformer 38. The water electrolyzer 31 in the water electrolysis system 17 plays the role of producing hydrogen by electrolyzing pure water supplied by the pure water adjustment device 33, with power supplied via the DC connection terminal 35b of the power converter 35.

[0022] As shown in Figure 2B, the water electrolysis apparatus 31 is configured to include, for example, first to fourth electrolytic stacks 32A to 32D. When no particular distinction is required between the first to fourth electrolytic stacks 32A to 32D, they are collectively referred to as the electrolytic stack 32.

[0023] In the water electrolysis device 31, the first and second electrolytic stacks 31A and 31B are electrically connected in series, and the third and fourth electrolytic stacks 31C and 31D are electrically connected in series. The pairs of the first and second electrolytic stacks 31A and 31B, and the pairs of the third and fourth electrolytic stacks 31C and 31D, are electrically connected in parallel to the DC side connection terminal 35b of the power converter 35.

[0024] Each of the first to fourth electrolytic stacks 32A to 32D is connected to a pure water pipe 33a, a hydrogen water pipe 33b, and an oxygen water pipe 33c, respectively, for the inflow and outflow of pure water supplied by the pure water adjustment device 33. The hydrogen water pipe 33b installed in the electrolytic stack 32 discharges pure water (hydrogen water) containing hydrogen produced by the electrolysis of pure water in the electrolytic stack 32. The oxygen water pipe 33c installed in the electrolytic stack 32 discharges pure water (oxygen water) containing oxygen produced by the electrolysis of pure water in the electrolytic stack 32.

[0025] Flow rate adjustment units 32A1 to 32D1 are interposed between the pure water piping 33a and each of the first to fourth electrolytic stacks 32A to 32D to adjust the amount of pure water flowing in.

[0026] The electrolytic stack 32 in the water electrolysis device 31 can be broadly classified into alkaline type and solid polymer type. In this embodiment, although not particularly limited, the case in which the solid polymer type is used as the electrolytic stack 32 is given as an example. The solid polymer electrolytic stack 32 has an advantage over the alkaline electrolytic stack in terms of response speed. Therefore, the solid polymer electrolytic stack 32 is preferred for application to the water electrolysis system 17, which is required to keep up with fluctuations in renewable energy. Furthermore, the solid polymer type electrolytic stack 32 has an advantage in terms of space saving compared to the alkaline type electrolytic stack. For this reason, the solid polymer type electrolytic stack 32 is preferable for application to water electrolysis systems 17 where space saving is required, such as offshore wind power generation systems.

[0027] As shown in Figure 2C, the pure water adjustment device 33 supplies pure water to the water electrolysis device 31 and also plays a role in recovering the hydrogen and oxygen produced by the electrolysis of pure water in the water electrolysis device 31 by separating them from the pure water (hydrogen water and oxygen water) discharged from the water electrolysis device 31.

[0028] The pure water adjustment device 33 comprises a pure water tank 41, a first gas-liquid separator 43, and a second gas-liquid separator 45.

[0029] The pure water tank 41 has the function of storing pure water supplied to the water electrolysis device 31, as well as pure water separated into gas and liquid by the first gas-liquid separator 43 and the second gas-liquid separator 45.

[0030] The pure water tank 41 is connected to a pure water piping 33a used to supply pure water to the water electrolysis device 31. The pure water piping 33a is equipped with a water supply pump 41a, a heat exchanger 41b, and a flow control valve 41c, in order from closest to the pure water tank 41.

[0031] The pure water stored in the pure water tank 41 is transported under pressure by the water pump 41a, its temperature is adjusted by the heat exchanger 41b, and its flow rate is adjusted by the flow control valve 41c before being supplied to the water electrolysis device 31 via the pure water piping 33a.

[0032] The first gas-liquid separation device 43 receives pure water (hydrogen water) containing hydrogen produced by the electrolysis of pure water by the water electrolysis device 31 via the hydrogen water piping 33b, and has the function of recovering hydrogen by performing gas-liquid separation treatment on the received hydrogen water. The hydrogen water piping 33b connected to the first gas-liquid separation device 43 is equipped with a flow control valve 43a for adjusting the amount of hydrogen water flowing in.

[0033] A pure water tank 41 is connected to the first gas-liquid separator 43 via a pure water pipe 43b. The pure water after the gas-liquid separation treatment by the first gas-liquid separator 43 is sent to the pure water tank 41 via the pure water pipe 43b.

[0034] The first gas-liquid separator 43 is connected to a hydrogen storage tank 34 via a hydrogen pipe 43c. The hydrogen pipe 43c is equipped with a pressure regulating valve 43d for adjusting the internal pressure of the first gas-liquid separator 43. The hydrogen after the gas-liquid separation process in the first gas-liquid separator 43 is sent to the hydrogen storage tank 34 via the pressure regulating valve 43d and the hydrogen pipe 43c, respectively.

[0035] The second gas-liquid separation device 45 receives oxygen-containing pure water (oxygenated water) produced by the electrolysis of pure water by the water electrolysis device 31 via the oxygenated water piping 33c, and has the function of recovering oxygen by performing gas-liquid separation treatment on the received oxygenated water. The oxygenated water piping 33c, which is connected in communication with the first gas-liquid separation device 43, is equipped with a flow control valve 45a for adjusting the amount of oxygenated water flowing in.

[0036] A pure water tank 41 is connected to the second gas-liquid separator 45 via a pure water pipe 45b. The pure water after the gas-liquid separation treatment by the second gas-liquid separator 45 is sent to the pure water tank 41 via the pure water pipe 45b.

[0037] The second gas-liquid separator 45 is connected to the atmosphere via an oxygen pipe 45c. The oxygen pipe 45c is equipped with a pressure regulating valve 45d for adjusting the internal pressure of the second gas-liquid separator 45. The oxygen after the gas-liquid separation process in the second gas-liquid separator 45 is discharged to the atmosphere via the pressure regulating valve 45d and the oxygen pipe 45c, respectively. However, it is also acceptable to connect an oxygen storage tank (not shown) to the second gas-liquid separator 45 and store the oxygen after the gas-liquid separation process performed by the second gas-liquid separator 45 in the oxygen storage tank (not shown).

[0038] In the water electrolysis system 17, water electrolysis is performed using power supplied to the water electrolyzer 31 via a power converter 35, etc. Specifically, as shown in Figure 2A, a transformer 38 is connected to the AC side connection terminal 35a of the power converter 35. The transformer 38 is connected to the grid 15 via a switch 39. The water electrolysis system 17 performs water electrolysis by supplying power from the grid 15 (power generated by the renewable energy generation system 13) to the water electrolyzer 31 by adjusting the output of the power converter 35.

[0039] To accurately perform such water electrolysis, the water electrolysis system 17 is equipped with an electrolysis control device 37. The electrolysis control device 37 acquires information on the operating status, including the operating status of the water electrolysis device 31, the pure water adjustment device 33, the power converter 35, and the switch 39, and plays a role in performing accurate electrolysis control based on the acquired operating status.

[0040] [Control device 19 of renewable energy-linked water electrolysis system 11] Next, the control device 19 of the renewable energy-linked water electrolysis system 11 will be described with reference to Figure 1A. The control device 19 of the renewable energy interconnected water electrolysis system 11 has the function of coordinating the output control of the generated power related to the renewable energy power generation system 13 and the electrolysis power control related to the water electrolysis system 17.

[0041] To realize the above functions, the control device 19 of the renewable energy-linked water electrolysis system 11 is configured to include an acquisition unit 21, a calculation unit 23, a setting unit 25, and a coordination control unit 27, as shown in Figure 1A.

[0042] The acquisition unit 21 has the function of acquiring the output power limit command value R_Grid related to the renewable energy power generation system 13, and the electrolysis power upper limit value P_UP, which is the upper limit of the electrolysis power related to the water electrolysis system 17.

[0043] Here, the output power limit command value R_Grid for the renewable energy power generation system 13 is, as described above, the upper limit of the power generated by the renewable energy power generation system 13, which is imposed based on the request of the grid operator who operates the grid 15, the operating status of the water electrolysis system 17, etc., in order to ensure the stable operation of the grid 15.

[0044] In cases where output restrictions are imposed on the renewable energy power generation system 13, the control device 19 of the renewable energy interconnected water electrolysis system 11 operates in coordination with the output control of the renewable energy power generation system 13 and the electrolysis power control of the water electrolysis system 17, taking into account that the transmission power value R_SY output from the renewable energy interconnected water electrolysis system 11 to the grid 15 should be limited to less than the output power restriction command value R_Grid.

[0045] Furthermore, the acquisition unit 21 acquires information related to the renewable energy power generation system 13, information related to the control device that manages the power supply and power consumption equipment, instruction information from organizations that manage the operational status of the wide-area power grid, and electricity market transaction information (electricity market information). Examples of electricity market transaction information include spot price information for electricity charges.

[0046] Furthermore, the acquisition unit 21 acquires the following information related to the renewable energy power generation system 13: predicted power generation value R_PR, rated power generation value R_RV, measured power generation value R_MV, and power generation command value R_CV; voltage information related to the grid 15; hydrogen remaining amount information related to the hydrogen storage tank 34; and electrolysis power rated value P_RV, electrolysis power upper limit value P_UP, electrolysis power measured value P_MV, and electrolysis power command value P_CV related to the water electrolysis system 17.

[0047] The calculation unit 23 calculates the generation power threshold R_SUM (=R_Grid+P_UP: see Figure 4), which is the sum of the output power limit command value R_Grid and the electrolytic power upper limit value P_UP acquired by the acquisition unit 21.

[0048] The setting unit 25 basically sets the power generation limit value R_UP, which is the upper limit of the power generated by the renewable energy power generation system 13, to be less than or equal to the power generation threshold R_SUM calculated by the calculation unit 23.

[0049] Furthermore, the setting unit 25 may set the electrolytic power upper limit P_UP for the water electrolysis system 17 based on the electrolytic power rating P_RV for the water electrolysis system 17, as shown in the first setting example in Figure 1B. Specifically, for example, the setting unit 25 may set the electrolytic power rating P_RV for the water electrolysis system 17 as the electrolytic power upper limit P_UP for the water electrolysis system 17 (P_UP = P_RV). Here, the electrolytic power rating P_RV for the water electrolysis system 17 is the value of electrolytic power that allows the water electrolysis treatment of the water electrolysis system 17 to be performed stably.

[0050] Furthermore, the setting unit 25 may also set the electrolysis power upper limit P_UP for the water electrolysis system 17 based on the storage state of the hydrogen storage tank 34 (storage device: see Figure 2C) that stores the hydrogen produced by the water electrolysis system 17, as shown in the second setting example in Figure 1C. The hydrogen storage tank 34 is equipped with a hydrogen level sensor (not shown) that detects the remaining amount of stored hydrogen. The hydrogen level detected by the hydrogen level sensor is sent to the setting unit 25 via the acquisition unit 21.

[0051] For example, the setting unit 25 may adopt a configuration in which it sets the upper limit value P_UP of the electrolysis power related to the water electrolysis system 17 to a large value when the hydrogen remaining amount is low, and to a small value when the hydrogen remaining amount is high, based on the hydrogen remaining amount detected by the hydrogen remaining amount sensor.

[0052] Specifically, for example, if the hydrogen remaining amount in the hydrogen storage tank 34 is below a predetermined remaining amount threshold, the setting unit 25 considers that there is sufficient capacity to store the produced hydrogen and sets the electrolysis power upper limit P_UP for the water electrolysis system 17 to a value based on the hydrogen remaining amount (with sufficient capacity) in the hydrogen storage tank 34. In this case, the setting unit 25 may also set the electrolysis power upper limit P_UP for the water electrolysis system 17 to a predetermined value (for example, the electrolysis power rating P_RV) that takes into account that the water electrolysis system 17 is in an operating state in which it can perform water electrolysis processing without any particular restrictions, instead of a value based on the hydrogen remaining amount (with sufficient capacity) in the hydrogen storage tank 34.

[0053] On the other hand, if the remaining amount of hydrogen in the hydrogen storage tank 34 exceeds a predetermined remaining amount threshold, the setting unit 25 considers that there is no room to store the produced hydrogen and sets the upper limit value P_UP of the electrolysis power for the water electrolysis system 17 to a value based on the remaining amount of hydrogen in the hydrogen storage tank 34 (no room to spare). In this case, the setting unit 25 should set the upper limit value P_UP of the electrolysis power for the water electrolysis system 17 to a predetermined value (for example, zero) that takes into account that the water electrolysis process for the water electrolysis system 17 is in an operating state where it is not possible to perform water electrolysis.

[0054] The coordinated control unit 27 basically coordinates the output control of the power generated by the renewable energy power generation system 13 and the electrolysis power control of the water electrolysis system 17 so that the measured power generation value R_MV related to the renewable energy power generation system 13 does not exceed the upper limit value R_UP of the power generation system set by the setting unit 25. Furthermore, instead of the measured power generation value R_MV for the renewable energy power generation system 13, the power generation command value R_CV for the renewable energy power generation system may be used.

[0055] The control device 19 of the renewable energy-linked water electrolysis system 11, configured as described above, is composed of a computer equipped with, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc. In the control device 19, a predetermined program (control program) stored in ROM is loaded into RAM and executed by the CPU, thereby being implemented. The program referred to here is a program that causes the computer to execute a control method.

[0056] [Operation of the control device 19 of the renewable energy-linked water electrolysis system 11] Next, the operation of the control device 19 of the renewable energy-linked water electrolysis system 11 will be explained with reference to Figure 3. Figure 3 is a flowchart illustrating the operation of the control device 19 of the renewable energy-linked water electrolysis system 11. As a prerequisite, the renewable energy grid-connected water electrolysis system 11 according to the embodiment of the present invention is assumed to be subject to output restrictions on the power generated by the renewable energy power generation system 13. Specifically, an output power restriction command value R_Grid is issued to the renewable energy power generation system 13, indicating that the upper limit of its output should be restricted. Furthermore, the renewable energy generation system 13 is capable of outputting power exceeding the output power limit command value R_Grid when the water electrolysis system 17 is in an operational state.

[0057] In step S11 shown in Figure 3, the acquisition unit 21 provided in the control device 19 of the renewable energy-linked water electrolysis system 11 performs basic information acquisition processing. In other words, the acquisition unit 21 acquires the output power limit command value R_Grid related to the renewable energy power generation system 13, and the electrolysis power limit value P_UP, which is the upper limit of the electrolysis power related to the water electrolysis system 17. Furthermore, the acquisition unit 21 acquires the following information related to the renewable energy power generation system 13: predicted power generation value R_PR, rated power generation value R_RV, measured power generation value R_MV, and power generation command value R_CV; voltage information related to the grid 15; hydrogen remaining amount information related to the hydrogen storage tank 34; and electrolysis power rated value P_RV, electrolysis power upper limit value P_UP, electrolysis power measured value P_MV, and electrolysis power command value P_CV related to the water electrolysis system 17.

[0058] In step S12, the control device 19 of the renewable energy interconnected water electrolysis system 11 determines whether or not it has acquired the output power limit command value R_Grid related to the renewable energy power generation system 13.

[0059] If the determination in step S12 does not result in the acquisition of the output power limit command value R_Grid for the renewable energy power generation system 13, the control device 19 of the renewable energy interconnected water electrolysis system 11 proceeds to step S13. On the other hand, if the determination in step S12 results in the acquisition of the output power limit command value R_Grid for the renewable energy power generation system 13, the control device 19 of the renewable energy interconnected water electrolysis system 11 jumps the processing flow to step S14. According to the preconditions, the control device 19 of the renewable energy-linked water electrolysis system 11 will, as a result of the determination in step S12, jump the processing flow to step S14.

[0060] In step S13, the control device 19 of the renewable energy-connected water electrolysis system 11 performs coordinated control related to the normal operating mode. After that, the control device 19 terminates the series of operations. The coordinated control related to the normal operating mode will be described in detail later.

[0061] In step S14, the calculation unit 23 in the control device 19 of the renewable energy interconnected water electrolysis system 11 calculates the power generation threshold R_SUM (=R_Grid+P_UP: see Figure 4), which is the sum of the output power limit command value R_Grid and the electrolysis power upper limit value P_UP acquired by the acquisition unit 21.

[0062] In step S15, the control device 19 of the renewable energy grid-connected water electrolysis system 11 determines whether the predicted power generation value R_PR for the renewable energy power generation system 13 is equal to or greater than the power generation threshold R_SUM (R_PR => R_SUM?). Step S15 determines whether the operating state of the renewable energy power generation system 13 is in a state where it can output power exceeding the power generation threshold R_SUM, which is the sum of the output power limit command value R_Grid and the electrolysis power upper limit value P_UP.

[0063] If the determination in step S15 indicates that the predicted power generation value R_PR for the renewable energy power generation system 13 is equal to or greater than the power generation threshold R_SUM (Yes in step S15), the control device 19 of the renewable energy interconnected water electrolysis system 11 proceeds to step S16. On the other hand, if the determination in step S15 is made that the predicted power generation value R_PR for the renewable energy power generation system 13 is less than the power generation threshold R_SUM (No in step S15), the control device 19 of the renewable energy interconnected water electrolysis system 11 jumps the processing flow to step S17.

[0064] In step S16, the coordination control unit 27 in the control device 19 of the renewable energy-connected water electrolysis system 11 performs coordination control related to the first operating mode. After that, the control device 19 terminates the series of operations. Details of the coordination control related to the first operating mode will be described later.

[0065] In step S17, the control device 19 of the renewable energy interconnected water electrolysis system 11 determines whether the predicted power generation value R_PR for the renewable energy power generation system 13 is equal to or greater than the upper limit value P_UP for electrolysis power related to the water electrolysis system 17 (R_PR=>P_UP?). In step S17, it is determined whether the operating state of the renewable energy power generation system 13 is in a state in which the water electrolysis treatment related to the water electrolysis system 17 can be sufficiently performed.

[0066] If the determination in step S17 is that the predicted power generation value R_PR for the renewable energy power generation system 13 is equal to or greater than the upper limit value P_UP for electrolysis power for the water electrolysis system 17 (Yes in step S17), the control device 19 of the renewable energy interconnected water electrolysis system 11 proceeds to step S18. On the other hand, if the determination in step S17 is made that the predicted power generation value R_PR for the renewable energy power generation system 13 is less than the upper limit value P_UP for the electrolysis power related to the water electrolysis system 17 (No in step S17), the control device 19 of the renewable energy interconnected water electrolysis system 11 jumps the processing flow to step S19.

[0067] In step S18, the coordination control unit 27 in the control device 19 of the renewable energy-connected water electrolysis system 11 performs coordination control related to the second operating mode. After that, the control device 19 terminates the series of operations. Details of the coordination control related to the second operating mode will be described later.

[0068] In step S19, the coordination control unit 27 in the control device 19 of the renewable energy-connected water electrolysis system 11 performs coordination control related to the third operating mode. After that, the control device 19 terminates the series of operations. Details of the coordination control related to the third operating mode will be described later.

[0069] [Time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11] Next, the time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11 will be explained with reference to Figure 4. Figure 4 is a time chart diagram illustrating the time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11. In Figure 4, the horizontal axis represents time, and the vertical axis represents power. Figure 4 shows the time-series changes of the electrolysis power upper limit P_UP for the water electrolysis system 17, the output power limit command value R_Grid for the renewable energy generation system 13, and the generation power threshold R_SUM (=R_Grid+P_UP), which is the sum of these two values.

[0070] As shown in Figure 4, during the period from time t0 to t1, the predicted power generation value R_PR for the renewable energy generation system 13 is less than the upper limit value P_UP for the electrolysis power of the water electrolysis system 17 (No. in step S17). This corresponds to (step S19: third operating mode) in the operation flowchart shown in Figure 3. During the period from time t0 to t1, the measured power generation value R_MV (substantially equivalent to the power generation command value R_CV) for the renewable energy power generation system 13 follows a common trajectory with the predicted power generation value R_PR and the measured electrolysis power value P_MV (substantially equivalent to the electrolysis power command value P_CV) for the water electrolysis system 17. In short, during the period t0-t1, all of the electricity generated by the renewable energy generation system 13 is consumed by the electrolysis power generated by the water electrolysis system 17. In this case, the transmission power value R_SY output to the grid 15 is zero (transmission power value R_SY = measured power generation value R_MV - measured electrolysis power value P_MV = 0). During the period from time t0 to t1, the electrolytic power range P_EL_RG for the water electrolysis system 17 can be expressed as a range from zero to the upper limit of electrolytic power P_UP, as shown in Figure 4.

[0071] During the period from time t1 to t2, the predicted power generation value R_PR for the renewable energy generation system 13 is less than the power generation threshold R_SUM (No in step S15), and greater than or equal to the upper limit of electrolysis power P_UP for the water electrolysis system 17 (Yes in step S17). This corresponds to (step S18: second operating mode) in the operation flowchart shown in Figure 3. During the same period t1-t2, the measured power generation value R_MV (substantially equivalent to the power generation command value R_CV) for the renewable energy power generation system 13 follows a common trajectory with the predicted power generation value R_PR. However, the measured electrolysis power value P_MV (substantially equivalent to the electrolysis power command value P_CV) for the water electrolysis system 17 follows a common trajectory with the upper limit electrolysis power value P_UP for the water electrolysis system 17. In short, during the period t1-t2, a portion of the power generated by the renewable energy generation system 13 [electrolysis power upper limit P_UP] is consumed by the electrolysis power of the water electrolysis system 17, and the surplus power [= measured power generation value R_MV - electrolysis power upper limit P_UP] is transmitted to the grid 15. In this case, the transmitted power value R_SY output to the grid 15 takes the value of the power range P_SY_RG [electrolysis power upper limit P_UP ~ power generation threshold R_SUM] transmitted to the grid 15 (transmitted power value R_SY = measured power generation value R_MV - electrolysis power upper limit P_UP).

[0072] During the period from time t2 to t3, the predicted power generation value R_PR for the renewable energy generation system 13 is greater than or equal to the power generation threshold R_SUM (Yes in step S15). This corresponds to (step S16: first operating mode) in the operation flowchart shown in Figure 3. During the same period t2-t3, the measured power generation value R_MV (essentially synonymous with the power generation command value R_CV) for the renewable energy power generation system 13 follows a trajectory common to the power generation threshold R_SUM, being smaller than the predicted power generation value R_PR. Similarly, the measured electrolysis power value P_MV (essentially synonymous with the electrolysis power command value P_CV) for the water electrolysis system 17 also follows a trajectory common to the upper limit of electrolysis power P_UP for the water electrolysis system 17. In short, during the period from time t2 to t3, the portion of the predicted power generation value R_PR related to the renewable energy generation system 13 that exceeds the power generation threshold R_SUM is restricted (measured power generation value R_MV = power generation threshold R_SUM: see "Power generation range P_LM_RG to which output restrictions are imposed on the renewable energy generation system" shown in Figure 4). Furthermore, during the same period t2-t3, a portion of the power generated by the renewable energy generation system 13 [= power generation threshold R_SUM] [electrolysis power upper limit P_UP] is consumed by the water electrolysis system 17, and the surplus power [= power generation threshold R_SUM - electrolysis power upper limit P_UP] is transmitted to the grid 15. In this case, the transmitted power value R_SY output to the grid 15 can be expressed as [transmitted power value R_SY = power generation threshold R_SUM - electrolysis power upper limit P_UP].

[0073] Since the operation during the period from time t3 to t4 is essentially the same as that during the period from time t1 to t2, a redundant explanation will be omitted. Similarly, the operation during the period from time t4 onward is essentially the same as that during the period from time t0 to t1, so we will omit the redundant explanation.

[0074] [Time-series operation of the control device 19 of the renewable energy-connected water electrolysis system 11 in the first operating mode] Next, the time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11 in the first operating mode will be explained with reference to Figure 5. Figure 5 is a time chart illustrating the time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11 in the first operating mode.

[0075] In the first operating mode, the setting unit 25 in the control device 19 of the renewable energy interconnected water electrolysis system 11 sets the measured power generation value R_MV (substantially equivalent to the power generation command value R_CV) related to the renewable energy power generation system 13 to a value common to the power generation threshold value R_SUM. In addition, the setting unit 25 in the control device 19 sets the measured electrolysis power value P_MV (substantially equivalent to the electrolysis power command value P_CV) related to the water electrolysis system 17 to a value common to the electrolysis power upper limit value P_UP.

[0076] Next, the coordinate control unit 27 in the control device 19 of the renewable energy interconnected water electrolysis system 11 sends the power generation threshold R_SUM, which is the power generation command value R_CV related to the renewable energy power generation system 13, to the renewable energy power generation system 13. In response, the renewable energy generation system 13 controls the output of generated power while maintaining the generated power threshold R_SUM as the generated power command value R_CV.

[0077] Furthermore, the coordinate control unit 27 in the control device 19 of the renewable energy-linked water electrolysis system 11 sends the electrolysis power upper limit value P_UP, which is the electrolysis power command value P_CV related to the water electrolysis system 17, to the water electrolysis system 17. In response, the renewable energy generation system 13 controls the electrolysis power while maintaining the upper limit value P_UP as the electrolysis power command value P_CV.

[0078] In the first operating mode, a portion of the power generated by the renewable energy generation system 13 [= power generation threshold R_SUM] [electrolysis power upper limit P_UP] is consumed as electrolysis power by the water electrolysis system 17, and the surplus power [= power generation threshold R_SUM - electrolysis power upper limit P_UP] is transmitted to the grid 15.

[0079] [Time-series operation of the control device 19 of the renewable energy-connected water electrolysis system 11 in the second operating mode] Next, the time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11 in the second operating mode will be explained with reference to Figure 6. Figure 6 is a time chart illustrating the time-series operation of the control device 19 of the renewable energy-connected water electrolysis system 11 in the second operating mode.

[0080] In the second operating mode, the setting unit 25 in the control device 19 of the renewable energy interconnected water electrolysis system 11 sets the measured power generation value R_MV (substantially equivalent to the power generation command value R_CV) related to the renewable energy power generation system 13 to a value common to the predicted power generation value R_PR. In addition, the setting unit 25 in the control device 19 sets the measured electrolysis power value P_MV (substantially equivalent to the electrolysis power command value P_CV) related to the water electrolysis system 17 to a value common to the electrolysis power upper limit value P_UP.

[0081] Next, the coordinate control unit 27 in the control device 19 of the renewable energy interconnected water electrolysis system 11 sends the predicted power generation value R_PR, which is the power generation command value R_CV for the renewable energy power generation system 13, to the renewable energy power generation system 13. In response, the renewable energy generation system 13 controls the output of generated power without output limitations, while keeping the power generation command value R_CV in line with the power generation prediction value R_PR.

[0082] Furthermore, the coordinate control unit 27 in the control device 19 of the renewable energy-linked water electrolysis system 11 sends the electrolysis power upper limit value P_UP, which is the electrolysis power command value P_CV related to the water electrolysis system 17, to the water electrolysis system 17. In response, the renewable energy generation system 13 controls the electrolysis power while maintaining the upper limit value P_UP as the electrolysis power command value P_CV.

[0083] In the second operating mode, a portion of the power generated by the renewable energy generation system 13 [= predicted power generation value R_PR] [electrolysis power upper limit value P_UP] is consumed as electrolysis power by the water electrolysis system 17, and the surplus power [= predicted power generation value R_PR - electrolysis power upper limit value P_UP] is transmitted to the grid 15.

[0084] [Time-series operation of the control device 19 of the renewable energy-connected water electrolysis system 11 in the third operating mode] Next, the time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11 in the third operating mode will be explained with reference to Figure 7. Figure 7 is a time chart illustrating the time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11 in the third operating mode.

[0085] In the third operating mode, the setting unit 25 in the control device 19 of the renewable energy interconnected water electrolysis system 11 sets the measured power generation value R_MV (substantially equivalent to the power generation command value R_CV) related to the renewable energy power generation system 13 to a value common to the predicted power generation value R_PR. In addition, the setting unit 25 in the control device 19 sets the measured electrolysis power value P_MV (substantially equivalent to the electrolysis power command value P_CV) related to the water electrolysis system 17 to a value common to the predicted power generation value R_PR.

[0086] Next, the coordinate control unit 27 in the control device 19 of the renewable energy interconnected water electrolysis system 11 sends the predicted power generation value R_PR, which is the power generation command value R_CV for the renewable energy power generation system 13, to the renewable energy power generation system 13. In response, the renewable energy generation system 13 controls the output of generated power without output limitations, while keeping the power generation command value R_CV in line with the power generation prediction value R_PR.

[0087] Furthermore, the coordinate control unit 27 in the control device 19 of the renewable energy interconnected water electrolysis system 11 sends the power generation command value R_CV, which is the electrolysis power command value P_CV related to the water electrolysis system 17, to the water electrolysis system 17. In response, the renewable energy generation system 13 performs electrolysis power control while making the electrolysis power command value P_CV follow the power generation command value R_CV.

[0088] In the third operating mode, the water electrolysis system 17 is operated in accordance with the power output command value of the renewable energy generation system 13, so as to follow the output of the renewable energy generation system 13. All of the power generated by the renewable energy generation system 13 [= predicted power output value R_PR] [= power output command value R_CV] is consumed by the electrolysis power of the water electrolysis system 17. As a result, there is no surplus power, and therefore it is not transmitted to the grid 15.

[0089] Figure 8 is a time chart illustrating the operation when the electrolysis power of the water electrolysis system 17, which is installed in the renewable energy-connected water electrolysis system 11, is offset.

[0090] In the first to third operating modes, the water electrolysis system 17 is operated based on an electrolysis power command value P_CV obtained by subtracting an offset from the power that the water electrolysis system 17 can consume.

[0091] This offset is provided, for example, to prevent the water electrolysis system 17 from receiving power from the grid 15 when the electrolysis power consumed by the water electrolysis system 17 exceeds the power generated by the renewable energy generation system 13.

[0092] With this configuration, it is possible to realize a renewable energy-connected water electrolysis system 11 suitable for applications that produce hydrogen using only renewable energy, as well as a control device 19 and control method for the renewable energy-connected water electrolysis system 11.

[0093] [Time-series operation of the control device 19 of the renewable energy-connected water electrolysis system 11 in normal operating mode] Next, the time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11 in normal operation mode (comparative example) will be explained with reference to Figure 9. Figure 9 is a time chart illustrating the time-series operation of the control device 19 of the renewable energy-linked water electrolysis system 11 in its normal operating mode (comparative example).

[0094] In the normal operation mode (comparative example: see step S13 shown in Figure 3), the setting unit 25 in the control device 19 of the renewable energy interconnected water electrolysis system 11 sets the measured power generation value R_MV (substantially equivalent to the power generation command value R_CV) related to the renewable energy power generation system 13 to a value common to the predicted power generation value R_PR. Furthermore, the setting unit 25 in the control device 19 sets the electrolytic power measurement value P_MV (substantially synonymous with the electrolytic power command value P_CV) related to the water electrolysis system 17 to a value that follows the power generation command value R_CV during the period from time t0 to t11 and from time t14 onward, while setting it to a value common to the electrolytic power upper limit value P_UP during the period from time t11 to t14.

[0095] Next, the coordinate control unit 27 in the control device 19 of the renewable energy interconnected water electrolysis system 11 sends the predicted power generation value R_PR, which is the power generation command value R_CV for the renewable energy power generation system 13, to the renewable energy power generation system 13. In response, the renewable energy generation system 13 controls the output of generated power without output limitations, while keeping the power generation command value R_CV in line with the power generation prediction value R_PR.

[0096] Furthermore, the coordinate control unit 27 provided in the control device 19 of the renewable energy-linked water electrolysis system 11 sends the power generation command value R_CV and the upper limit value P_UP of the electrolysis power, which are the electrolysis power command value P_CV related to the water electrolysis system 17, to the water electrolysis system 17. In response, the renewable energy generation system 13 controls the electrolysis power by making the electrolysis power command value P_CV follow the power generation command value R_CV during the period from time t0 to t11 and from time t14 onward, while controlling the electrolysis power by fixing the electrolysis power command value P_CV to the electrolysis power upper limit value P_UP during the period from time t11 to t14.

[0097] During the period from time t0-t11 and from time t14 onward in normal operation mode, the water electrolysis system 17 is operated to follow the power output command value R_CV of the renewable energy power generation system 13. In this case, all of the power generated by the renewable energy power generation system 13 [=power output command value R_CV] is consumed by the electrolysis power of the water electrolysis system 17. As a result, there is no surplus power, and therefore it is not transmitted to the grid 15.

[0098] On the other hand, during the period from time t11 to t14 in normal operation mode, the renewable energy generation system 13 is operated to follow the predicted power generation value R_PR. The water electrolysis system 17 is operated with its electrolysis power upper limit value P_UP fixed. In this case, a portion of the power generated by the renewable energy generation system 13 [= electrolysis power upper limit value P_UP] is consumed by the electrolysis power of the water electrolysis system 17, and the surplus power [= power generation measurement value R_MV - electrolysis power upper limit value P_UP] is transmitted to the grid 15.

[0099] As described in the embodiments above, the renewable energy interconnected water electrolysis system 11, and the control device 19 and control method for the renewable energy interconnected water electrolysis system 11 according to the present invention have the following features. For the renewable energy grid-connected water electrolysis system 11, the water electrolysis system 17 is operated based on, for example, an output power limit command value R_Grid sent from an external source and the operating status of the renewable energy power generation system 13. At the same time, based on the output power limit command value R_Grid, etc., the coordinate control unit 27 provided in the control device 19 of the renewable energy grid-connected water electrolysis system 11 (which may also be a control device provided in the renewable energy power generation system 13 or the water electrolysis system 17) sets the upper limit value R_UP for power generation related to the renewable energy power generation system 13 and the upper limit value P_UP for electrolysis power related to the water electrolysis system 17, respectively. Based on the set power generation command value R_CV (upper limit value R_UP) and electrolysis power command value P_CV (upper limit value P_UP), the output control of power generation related to the renewable energy power generation system 13 and the electrolysis power control of the water electrolysis system 17 are coordinated. With this configuration, the renewable energy generation system 13 can output power exceeding the output power limit command value R_Grid, and the water electrolysis system 17 can also generate electrolysis power up to the electrolysis power upper limit value P_UP. As a result, the utilization rate of both equipment can be increased.

[0100] [Other Embodiments] The embodiments and examples described above illustrate examples of the present invention. Therefore, the technical scope of the present invention should not be interpreted as being limited by these descriptions, as the present invention can be implemented in various forms without departing from its gist or main features.

[0101] Furthermore, it is possible to replace some of the configurations of the embodiments described here with those of other embodiments, and even to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace some of the configurations of each embodiment with those of other embodiments.

[0102] Furthermore, the control lines and information lines shown are those deemed necessary for explanatory purposes, and not all control lines and information lines are necessarily shown in the actual product. In reality, it can be assumed that almost all components are interconnected.

[0103] Finally, each component, function, processing unit, etc., provided in the control device 19 of the renewable energy-linked water electrolysis system 11 according to the embodiment of the present invention may be implemented in hardware, either partially or entirely, by designing them as an integrated circuit, for example. Alternatively, each of the above-mentioned components, functions, processing units, etc., may be implemented in software by having a processor interpret and execute a program that realizes each function. Information such as programs, tables, and files that realize each function can be stored in a recording device such as memory, a hard disk, or an SSD (Solid State Drive), or in a recording medium such as an IC card, an SD card, or a DVD (Digital Versatile Disk). [Explanation of Symbols]

[0104] 11. Renewable energy-linked water electrolysis system 13 Renewable energy generation systems 15 strains 17 Water electrolysis system 19 Control device 21 Acquisition Department 23 Calculation Section 25 Settings Section 27 Coordination Control Unit P_UP Electrolytic Power Upper Limit R_Grid Output Power Limit Command Value R_SUM Power Generation Threshold

Claims

1. A renewable energy interconnected water electrolysis system comprising: a renewable energy power generation system that outputs power generated using renewable energy to the grid at least; and a water electrolysis system connected to the grid via a common interconnection point for the renewable energy power generation system, which receives the output of the power generated and produces hydrogen by electrolyzing water, wherein The system includes a control device that controls the output of the generated power related to the renewable energy power generation system and the electrolytic power related to the water electrolysis system, The control device is An acquisition unit that acquires the output power limit command value for the renewable energy generation system and the electrolysis power upper limit value, which is the upper limit of the electrolysis power for the water electrolysis system, A calculation unit calculates a power generation threshold value which is the sum of the output power limit command value and the electrolytic power upper limit value acquired by the acquisition unit, A setting unit sets the upper limit of power generation, which is the upper limit of power generation related to the renewable energy power generation system, to be less than or equal to the power generation threshold calculated by the calculation unit, A coordinated control unit that coordinates the output control of the renewable energy generation system and the electrolysis power control of the water electrolysis system so that the generated power of the renewable energy generation system does not exceed the upper limit of generated power set by the setting unit, A renewable energy-connected water electrolysis system characterized by being configured with the following features.

2. A control device for a renewable energy-connected water electrolysis system comprising: a renewable energy power generation system that outputs power generated using renewable energy to the grid at least; and a water electrolysis system connected to the grid via a common interconnection point for the renewable energy power generation system, which receives the output of the power generated and produces hydrogen by electrolyzing water, wherein the control device for the renewable energy-connected water electrolysis system comprises: An acquisition unit that acquires the output power limit command value for the renewable energy generation system and the electrolysis power upper limit value, which is the upper limit of the electrolysis power for the water electrolysis system, A calculation unit calculates a power generation threshold value which is the sum of the output power limit command value and the electrolytic power upper limit value acquired by the acquisition unit, A setting unit sets the upper limit of power generation, which is the upper limit of power generation related to the renewable energy power generation system, to be less than or equal to the power generation threshold calculated by the calculation unit, A coordinated control unit that coordinates the output control of the renewable energy generation system and the electrolysis power control of the water electrolysis system so that the generated power of the renewable energy generation system does not exceed the upper limit of generated power set by the setting unit, A control device for a renewable energy-connected water electrolysis system, characterized by being configured to include the following:

3. A control device for a renewable energy-linked water electrolysis system according to claim 2, The aforementioned setting unit is, The upper limit of the electrolytic power for the water electrolysis system is set based on the rated electrolytic power for the water electrolysis system. The aforementioned cooperative control unit, To ensure that the electrolytic power of the water electrolysis system does not exceed the set upper limit of electrolytic power, the output control of the power generated by the renewable energy generation system and the electrolytic power control of the water electrolysis system are coordinated. A control device for a renewable energy-linked water electrolysis system, characterized by the following features.

4. A control device for a renewable energy-linked water electrolysis system according to claim 2, The aforementioned setting unit is, The upper limit of the electrolysis power for the water electrolysis system is set based on the storage state of the hydrogen storage device for the hydrogen produced by the water electrolysis system. The aforementioned cooperative control unit, To ensure that the electrolytic power of the water electrolysis system does not exceed the set upper limit of electrolytic power, the output control of the power generated by the renewable energy generation system and the electrolytic power control of the water electrolysis system are coordinated. A control device for a renewable energy-linked water electrolysis system, characterized by the following features.

5. A control device for a renewable energy-linked water electrolysis system according to claim 3, The aforementioned setting unit is, When the output of the renewable energy generation system satisfies the conditions for being controllable beyond the power generation threshold, and the predicted power generation value for the renewable energy generation system falls within a first region exceeding the power generation threshold, the power generation of the renewable energy generation system is set to the power generation threshold, while the electrolysis power of the water electrolysis system is set to the rated electrolysis power value for the water electrolysis system. The aforementioned cooperative control unit, Based on the power generated by the renewable energy generation system and the electrolytic power of the water electrolysis system, as set by the setting unit, the output control of the power generated by the renewable energy generation system and the electrolytic power control of the water electrolysis system are coordinated. A control device for a renewable energy-linked water electrolysis system, characterized by the following features.

6. A control device for a renewable energy-linked water electrolysis system according to claim 3, The aforementioned setting unit is, When the output of the power generated by the renewable energy generation system satisfies the condition that it is controllable to a value less than the power generation threshold and exceeding the electrolytic power rating of the water electrolysis system, and the predicted power generation value of the renewable energy generation system falls into a second region where it exceeds the electrolytic power rating and is less than the power generation threshold, the power generated by the renewable energy generation system is set to a value that falls into the second region, while the electrolytic power of the water electrolysis system is set to the electrolytic power rating of the water electrolysis system. The aforementioned cooperative control unit, Based on the power generated by the renewable energy generation system and the electrolytic power of the water electrolysis system, as set by the setting unit, the output control of the power generated by the renewable energy generation system and the electrolytic power control of the water electrolysis system are coordinated. A control device for a renewable energy-linked water electrolysis system, characterized by the following features.

7. A control device for a renewable energy-linked water electrolysis system according to claim 3, The aforementioned setting unit is, If the predicted power generation value for the renewable energy generation system falls within the third region, which is less than or equal to the rated electrolysis power value for the water electrolysis system, the power generation value for the renewable energy generation system is set to a value common to the electrolysis power for the water electrolysis system. The aforementioned cooperative control unit, Based on the power generated by the renewable energy generation system and the electrolytic power of the water electrolysis system, as set by the setting unit, the output control of the power generated by the renewable energy generation system and the electrolytic power control of the water electrolysis system are coordinated. A control device for a renewable energy-linked water electrolysis system, characterized by the following features.

8. A control device for a renewable energy-linked water electrolysis system according to claim 3, The aforementioned setting unit is, When the conditions are met such that the power generated by the renewable energy generation system is controlled to be less than the rated electrolytic power of the water electrolysis system, the electrolytic power of the water electrolysis system is set to a value that is smaller than the power generated by a predetermined offset. The aforementioned cooperative control unit, Based on the electrolytic power related to the water electrolysis system set by the setting unit, the output control of the power generated by the renewable energy power generation system and the electrolytic power control of the water electrolysis system are coordinated. A control device for a renewable energy-linked water electrolysis system, characterized by the following features.

9. A control method used in a control device for a renewable energy-connected water electrolysis system comprising: a renewable energy power generation system that outputs power generated using renewable energy to at least the grid; and a water electrolysis system connected to the grid via a common interconnection point for the renewable energy power generation system, which receives the output of the power generated and produces hydrogen by electrolyzing water, the control method being used in a control device for a renewable energy-connected water electrolysis system, An acquisition step for acquiring the output power limit command value for the renewable energy generation system and the electrolysis power upper limit value, which is the upper limit of the electrolysis power for the water electrolysis system, A calculation step for calculating a power generation threshold value which is the sum of the acquired output power limit command value and the electrolytic power upper limit value, A setting step of setting the upper limit of power generation, which is the upper limit of power generation related to the renewable energy power generation system, to be less than or equal to the calculated power generation threshold, A coordinated control step is performed to coordinate the output control of the renewable energy generation system and the electrolysis power control of the water electrolysis system so that the power generated by the renewable energy generation system does not exceed the set upper limit of power generation, A method for controlling a renewable energy-linked water electrolysis system, characterized by having [a specific feature / feature].

10. A control method for a renewable energy-linked water electrolysis system according to claim 9, In the aforementioned setup process, The upper limit of the electrolytic power for the water electrolysis system is set based on the rated electrolytic power for the water electrolysis system. In the aforementioned cooperative control process, To ensure that the electrolytic power of the water electrolysis system does not exceed the set upper limit of electrolytic power, the output control of the power generated by the renewable energy generation system and the electrolytic power control of the water electrolysis system are coordinated. A method for controlling a renewable energy-linked water electrolysis system, characterized by the following features.

11. A control method for a renewable energy-linked water electrolysis system according to claim 9, In the aforementioned setup process, The upper limit of the electrolysis power for the water electrolysis system is set based on the storage state of the hydrogen storage device for the hydrogen produced by the water electrolysis system. In the aforementioned cooperative control process, To ensure that the electrolytic power of the water electrolysis system does not exceed the set upper limit of electrolytic power, the output control of the power generated by the renewable energy generation system and the electrolytic power control of the water electrolysis system are coordinated. A method for controlling a renewable energy-linked water electrolysis system, characterized by the following features.

12. A control method for a renewable energy-linked water electrolysis system according to claim 10, In the aforementioned setup process, When the output of the renewable energy generation system satisfies the conditions for being controllable beyond the power generation threshold, and the predicted power generation value for the renewable energy generation system falls within a first region exceeding the power generation threshold, the power generation of the renewable energy generation system is set to the power generation threshold, while the electrolysis power of the water electrolysis system is set to the rated electrolysis power value for the water electrolysis system. In the aforementioned cooperative control process, Based on the generated power from the renewable energy generation system and the electrolytic power from the water electrolysis system, the output control of the generated power from the renewable energy generation system and the electrolytic power control of the water electrolysis system are performed in coordination. A method for controlling a renewable energy-linked water electrolysis system, characterized by the following features.

13. A control method for a renewable energy-linked water electrolysis system according to claim 10, In the aforementioned setup process, When the output of the power generated by the renewable energy generation system satisfies the condition that it is controllable to a value less than the power generation threshold and exceeding the electrolytic power rating of the water electrolysis system, and the predicted power generation value of the renewable energy generation system falls into a second region where it exceeds the electrolytic power rating and is less than the power generation threshold, the power generated by the renewable energy generation system is set to a value that falls into the second region, while the electrolytic power of the water electrolysis system is set to the electrolytic power rating of the water electrolysis system. In the aforementioned cooperative control process, Based on the generated power from the renewable energy generation system and the electrolytic power from the water electrolysis system, the output control of the generated power from the renewable energy generation system and the electrolytic power control of the water electrolysis system are performed in coordination. A method for controlling a renewable energy-linked water electrolysis system, characterized by the following features.

14. A control method for a renewable energy-linked water electrolysis system according to claim 10, The aforementioned setting process is: If the predicted power generation value for the renewable energy generation system falls within the third region, which is less than or equal to the rated electrolysis power value for the water electrolysis system, the power generation value for the renewable energy generation system is set to a value common to the electrolysis power for the water electrolysis system. In the aforementioned cooperative control process, Based on the generated power from the renewable energy generation system and the electrolytic power from the water electrolysis system, the output control of the generated power from the renewable energy generation system and the electrolytic power control of the water electrolysis system are performed in coordination. A method for controlling a renewable energy-linked water electrolysis system, characterized by the following features.

15. A control method for a renewable energy-linked water electrolysis system according to claim 10, In the aforementioned setup process, When the conditions are met such that the power generated by the renewable energy generation system is controlled to be less than the rated electrolytic power of the water electrolysis system, the electrolytic power of the water electrolysis system is set to a value that is smaller than the power generated by a predetermined offset. In the aforementioned cooperative control process, Based on the electrolytic power of the water electrolysis system set above, the output control of the power generated by the renewable energy power generation system and the electrolytic power control of the water electrolysis system are to be performed in coordination. A method for controlling a renewable energy-linked water electrolysis system, characterized by the following features.

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