Decentralized energy management

Abstract

The invention relates to a method for supplying energy in an isolated island network (1) comprising a first electrical energy supply module (6) and a second electrical energy supply module (7), for which energy can be supplied either directly by a battery (8) or by a fuel cell (10) via a DC / DC converter (9), and jointly by the battery (8) and the fuel cell (10), wherein the electrical energy sources (4) of the isolated island network (1) each calculate their respective target values on the basis of the data of the respective remaining electrical energy sources (4) and of the electrical loads (5), and inform the respective remaining electrical energy sources (4) of the target values, the operating state of the first electrical energy supply module (6) being changed when needed, and the operating state of the second electrical energy supply module (7) being changed when needed. The operating state of the first electrical energy supply module (6) is changed in parallel in such a way that the first electrical energy supply module is no longer available for the electrical network supply, and the rechargeable battery (8) of the first electrical energy supply module (6) is charged to a predetermined state of charge, the operating state of the second electrical energy supply module (7) being changed in parallel in such a way that the second electrical energy supply module is available for the electrical network supply, and the required power grid load is met. The invention also relates to an isolated island grid (1).

Description

Decentralized energy management Technical Field

[0001] This invention relates to a method for energy supply in an islanded power grid and an islanded power grid. Background Technology

[0002] Isolated power grids, such as those on ships (especially specialized vessels) or on land, require high grid availability to mitigate increased risks to operational tasks (e.g., ship positioning, work at offshore facilities, power supply to computing facilities) even in the event of partial system or subsystem failure. Environmental regulations have also increased requirements for efficiency and the avoidance of harmful emissions. This has led to an increasing preference for fuel cells and energy storage devices in maintaining and providing the energy required for electric drives (e.g., ship propulsion and other highly available units and components). Because fuel cells, as energy converters, differ from traditional generator sets, new requirements must be placed on system architecture and related regulation in terms of operational safety, availability, and lifespan.

[0003] Energy storage devices, such as batteries, are fed or charged to the AC grid via a bidirectional DC / AC converter. In a DC grid, the battery is sometimes directly coupled to the DC bus or to it via a DC / DC regulator. In the case of direct coupling, the energy flow varies with the battery's state of charge (SOC) and the intermediate circuit voltage, which must be set according to the battery's requirements. In the case of a converter (AC / DC or DC / DC), the storage device is actively charged and discharged according to the SOC, based on a central Power Management System (PMS) or regulation system. The fuel cell is regulated by the PMS according to load requirements from the grid or according to the battery's SOC. Here, the dynamics of load changes negatively impact the fuel cell's lifespan. Therefore, energy storage devices (batteries) are often used to mitigate the load requirements on the fuel cell, as disclosed in US 11,621,432 B2. Summary of the Invention

[0004] The object of this invention is to provide an energy supply method for use in islanded power grids, particularly improving the lifespan of the involved components, using fuel cells and batteries as electrical energy sources. Another object of this invention is to provide a corresponding islanded power grid.

[0005] Regarding the objective of providing energy supply methods using fuel cells and batteries as electrical energy sources in islanded power grids, the present invention specifies that in such methods for energy supply in islanded power grids, the islanded power grid includes electrical conductors and multiple electrical units that can be connected via the conductors. These electrical units can be electrical energy sources or electrical loads. The electrical energy sources include a first electrical energy supply module and a second electrical energy supply module. For the first and second electrical energy supply modules, energy can be provided directly by batteries, provided by fuel cells via DC / DC converters, or provided jointly by batteries and fuel cells. The electrical energy sources in the islanded power grid report data, such as their actual values, reserves, and minimum target values, to the other electrical energy sources in the islanded power grid. The electrical loads in the islanded power grid report data, such as their actual values ​​and achievable maximum values, and the electrical energy sources in the islanded power grid allocate power based on the data from the corresponding other electrical energy sources and electrical loads. Each module calculates its own target value and informs the corresponding remaining electrical energy sources of this target value. Specifically, for the first energy supply module, the state of charge (SOC) of its battery is determined, and the operating point of its fuel cell or its DC / DC converter is controlled based on this SOC. When the SOC falls below the lower limit of the first energy supply module's battery SOC, the power of the first energy supply module's fuel cell is increased until the battery returns to the SOC or until the fuel cell reaches its upper power limit. If this is insufficient to charge the first energy supply module's battery, the operating state of the first energy supply module is changed so that it is no longer available for grid power supply, and the battery is charged to a predetermined SOC. Simultaneously, the operating state of the second energy supply module is changed so that it becomes available for grid power supply to meet the required grid load.

[0006] In this invention, the term "battery" is used in a broader sense, meaning it should be understood as an electrochemical-based energy storage device.

[0007] This invention is based on the understanding that in an islanded power grid, fuel cells and batteries are assembled in energy supply modules, and within each energy supply module, an energy management system maintains the state of charge (SOC) of the battery within a specified range, avoiding excessive dynamism in the fuel cell. In this configuration, energy can be supplied to the grid from either the battery or other energy storage devices, or from the fuel cell. When the maximum SOC is exceeded, the fuel cell drops to its minimum load, and energy is drawn only from the energy storage device. When the SOC falls below the storage device's minimum SOC, the fuel cell's power is increased until it reaches its maximum power. According to the invention, if the measures described here are insufficient to charge the battery, the operating state of the corresponding electrical energy supply module is set to "off," and this module is unavailable to the islanded power grid until the specified SOC is reached. Simultaneously, another electrical energy supply module is connected to the islanded power grid to meet the required grid load. Upon reaching the specified SOC, the operating state of the first electrical energy supply module is reset to "on," making it available to supply power to the grid again. This can be achieved with particular flexibility if electrical units, and especially electrical energy sources, have access to the same information at all times, and this information is evaluated locally (i.e., within each electrical unit itself) using the same algorithm. Whenever an electrical energy supply module registers in an islanded grid, it accordingly obtains specified parameters (e.g., operating hours, theoretical remaining lifespan, etc.) from other electrical energy supply modules in the islanded grid, and, if necessary, acquires priorities, allowing these modules to be switched on based on the power requirements and priorities of the loads in the grid.

[0008] Advantageously, as the battery of the primary power supply module reaches its maximum charge limit, the module's operating state is set to make it available again to supply power to the grid. By making the primary power supply module available again, a more reliable and continuous power supply is guaranteed. Furthermore, power demand in an islanded grid may vary depending on the time of day, weather conditions, or other factors. If the primary power supply module is available again, the grid can better cope with fluctuations in power demand.

[0009] Advantageously, data from individual electrical units is communicated to other electrical units or at least the power source in a time-controlled and periodic manner. Based on this data and using algorithms available to the individual units, the electrical units in the islanded grid are controlled. This well-coordinated data transmission avoids potential overloads or shortages. This helps maintain consistent system power and ensures stable operation. All electrical units in the islanded grid can calculate their target values ​​and adhere to their limits based on their own parameters and parameters fed back from other units. There is no centralized calculation or control of the electrical units. Each unit calculates its own appropriate requirements. This is feasible because each unit has the same, separately relevant algorithms.

[0010] Ideally, the prioritization of electrical units should be dynamically adjusted. In a power grid, demands and loads can vary over time. Dynamic prioritization allows grid managers to better balance loads and avoid shortages. Priorities can be adjusted, for example, by prioritizing critical components, to optimally handle peak load periods or specific demands. Furthermore, in modern power grids, energy sources and appliances are typically diverse and decentralized. Static prioritization can limit the grid's ability to respond to changing environments. Dynamic adjustments enable the integration of new units or technologies into the grid and their optimized use. In particular, the dynamics of power generation are even more variable when integrating renewable energy sources such as wind and solar power into the power grid. Dynamic prioritization can help balance fluctuations in power generation and maintain grid stability.

[0011] On ships, it is advantageous to specify priorities by selecting navigation configurations. For example, in a configuration with maximum energy efficiency, the corresponding energy source can be prioritized for operation. The situation is different in the maneuvering operations of warships. In this case, a reliable and stable energy source is required, even at the cost of environmental or economic factors. In ports, the opposite is true, where only the minimum emissions are permitted. Different operating states can be stored as fixed patterns, with a corresponding number of "power units" prepared.

[0012] It is appropriate to define the priority of electrical units using a priority list. This priority list can be advantageously adjusted based on an assessment of the operating hours of the electrical units.

[0013] Advantageously, redundancy requirements are defined, and when they fall below predetermined limits in an islanded power grid, the operating state of at least one unused power source is changed to make that power source available to supply power to the grid, thus satisfying the required redundancy. By selecting the number and power of power sources according to the desired operating configuration, each operating state can be presented with sufficient fault safety as specified. Simultaneously, the fuel cell can operate optimally (in terms of its lifespan).

[0014] Finally, it is advantageous to employ machine learning to optimize the operating parameters of the electrical energy supply module. The optimization of fuel cell power relative to the corresponding battery's state of charge can be continuously adjusted using artificial intelligence. To this end, AI monitors the frequency at which the fuel cell must change its power output to maintain the battery's state of charge within acceptable operating limits and predictively adjusts the fuel cell settings accordingly.

[0015] To achieve the purpose of an islanded power grid, an islanded power grid is provided, comprising electrical conductors and multiple electrical units that can be connected via these conductors. These electrical units can be power sources or power loads. The power sources include a first power supply module and a second power supply module. Energy for the first and second power supply modules can be provided directly by batteries, via a DC / DC converter from a fuel cell, or by a combination of batteries and fuel cells. The power sources in the islanded power grid are configured to report data, such as their actual values, reserves, and minimum target values, to the other power sources in the islanded power grid. The power loads in the islanded power grid are configured to report data, such as their actual values ​​and achievable maximum values, within the islanded power grid. Furthermore, the power sources in the islanded power grid are configured to calculate their own values ​​based on the data from the corresponding other power sources and power loads. The target value is set and communicated to the corresponding remaining electrical energy sources. The first electrical energy supply module is configured to determine the state of charge (SOC) of its battery and control the operating point of its fuel cell or its DC / DC converter based on the SOC. When the SOC falls below the lower limit of the first electrical energy supply module's battery SOC, the power of the first electrical energy supply module's fuel cell is increased until the battery changes to the SOC or until the fuel cell reaches its upper power limit. If this is insufficient to charge the first electrical energy supply module's battery, the operating state of the first electrical energy supply module is changed so that it is no longer available for grid power supply, and the battery of the first electrical energy supply module is charged to a predetermined SOC. Simultaneously, the operating state of the second electrical energy supply module is changed so that it becomes available for grid power supply to meet the required grid load.

[0016] In existing power grids, there is typically a centralized, highly redundant control unit responsible for power management. If this unit or its communication fails, and the grid is only in "emergency mode," manual operation is required; otherwise, the component will fail completely.

[0017] According to the present invention, each participating unit utilizes the same relevant algorithm and data from all participating units publicly available throughout the power grid to take over the regulation work, thereby eliminating the need for centralized control. Multiple unit failures may occur without causing significant deterioration of control functions in the islanded power grid. Furthermore, priorities and redundancy can be specified and adjusted during operation.

[0018] Combinations consisting of different energy sources, storage devices, and electrical appliances are also possible. This means that the composition of the power grid in terms of the type and number of its various modules can be freely configured.

[0019] Especially in the application of batteries and fuel cells, this invention proposes a solution that considers the dynamics of fuel cells and the lifespan of batteries. Until now, batteries have always been centrally allocated to various parts of the power grid. In the method according to the invention, fuel cells and batteries, along with their control systems, are combined and allocated to the power grid as a single unit. Thus, power generation can be freely configured according to usage conditions, and redundancy in the power grid can be freely configured. Attached Figure Description

[0020] The invention will be explained in more detail by way of example with reference to the accompanying drawings. Schematic and not precisely dimensional: Figure 1 shows a simplified diagram of an electrical distribution network with multiple electrical energy sources and appliances; and Figure 2 shows an energy supply module with batteries and fuel cells. Detailed Implementation

[0021] Figure 1 schematically and exemplary illustrates an islanded power grid 1 according to the present invention. In this figure, the selected power grid topology is shown as a bus. It is important to note that other power grid topologies, such as rings, mesh grids, trees, and other conceivable variations, can also be successfully employed. Different power grid topologies can be used to meet the specific requirements and circumstances of the corresponding application environments, which reflects the versatility of the present invention.

[0022] The isolated power grid 1 in the embodiment of Figure 1 includes electrical conductors 2 and multiple electrical units 3. These electrical units can be coupled to the isolated power grid 1 through the electrical conductors 2 and via a switch 11. These electrical units can be electrical energy sources 4 or electrical loads 5, i.e., electrical appliances. In the embodiment of Figure 1, the isolated power grid 1 includes a diesel generator 12, a steam turbine 13, a shaft-driven generator 14, a first energy supply module 6, and a second energy supply module 7, which serve as energy sources 4. The second energy supply module can have the same structure as the first energy supply module 6.

[0023] Figure 2 schematically and exemplary illustrates a first energy supply module 6. The first energy supply module 6 includes an appliance terminal 15, a battery 8 directly connected to the appliance terminal 15, a fuel cell 10 connected to the appliance terminal 15 via a DC / DC converter 9, and an energy management system 16. This energy management system controls the operating point of the fuel cell 10 or the operating point of the DC / DC converter 9 based on the state of charge of the battery 8. The first energy supply module 6 can supply energy to the islanded power grid 1 in various ways. Energy can be supplied directly by its battery 8, or via its fuel cell 10 through its DC / DC converter 8, or jointly by the battery 8 and the fuel cell 10. Internal control of the first energy supply module 6 is performed via a bus system 17, which is used for communication between the energy management system 16 and the battery management system 18, between the energy management system 16 and the fuel cell controller 19, and between the energy management system 16 and the DC / DC converter 9. All data required for the operation of the first energy supply module 6, such as current measurement data from the appliance terminal 15, control values, warnings, and error reports, are transmitted through this bus system 17. The electric power supply module 6 operates autonomously and can be integrated into the power grid without problems as needed, for example, it can also be integrated with multiple electric power supply modules 6, 7 that are independent of each other in terms of control and connected in parallel.

[0024] According to the present invention, the first electrical energy supply module 6 is configured to determine the state of charge (SOC) of its battery 8 and control the operating point of its fuel cell 10 or its DC / DC converter 9 based on the SOC of the battery 8. When the SOC of the battery 8 falls below the lower limit of the SOC of the first electrical energy supply module 6, the power of the fuel cell 10 of the first electrical energy supply module 6 is increased until the battery 8 changes back to the aforementioned SOC or until the fuel cell 10 has reached its upper power limit. If this is insufficient to charge the battery 8 of the first electrical energy supply module 6, the operating state of the first electrical energy supply module 6 is changed so that it is no longer available for grid power supply, and the battery 8 of the first electrical energy supply module 6 is charged to a predetermined SOC. Simultaneously, the operating state of the second electrical energy supply module 7 is changed so that it becomes available for grid power supply to meet the required grid load.

[0025] According to the present invention, the power source 4 of the islanded power grid 1 is configured to report data, such as its actual value, reserve and minimum target value, to the other power sources 4 in the islanded power grid 1 respectively, wherein the power load 5 of the islanded power grid 1 is configured to report data, such as its actual value and its achievable maximum value, in the islanded power grid 1, and wherein the power source 4 of the islanded power grid 1 is configured to calculate its own target value based on the data of the corresponding other power sources 4 and the power load 5, and to inform the corresponding other power sources 4 of the target value.

[0026] The islanded power grid 1 according to the present invention is by no means limited to the specific embodiment shown in FIG1. ​​The present invention includes numerous feasible designs and variations that may differ from the implementation shown in FIG1. ​​The decentralized energy management of the islanded power grid 1 provides the possibility of seamlessly integrating additional power sources 4 and electrical loads 5 into the system. This applies both to electrical units 3 of the same type and to different types of electrical units 3.

[0027] This invention opens up a wide range of applications and technical implementations. This flexibility allows for alternative topologies and arrangements that better suit the specific requirements and needs of the respective environment or application.

Claims

1. A method for energy supply in an islanded power grid (1), the islanded power grid (1) comprising electrical conductors (2) and a plurality of electrical units (3) connectable via the electrical conductors (2), the electrical units being electrical energy sources (4) or electrical loads (5), wherein, The electrical energy source (4) includes a first electrical energy supply module (6) and a second electrical energy supply module (7). For the first and second electrical energy supply modules, energy can be provided directly by a battery (8), by a fuel cell (10) via a DC / DC converter (9), or jointly by the battery (8) and the fuel cell (10). The electrical energy source (4) of the isolated power grid (1) communicates data to the other electrical energy sources (4) in the isolated power grid (1), for example, their... Each of the actual values, reserves, and minimum target values, wherein the power load (5) of the islanded power grid (1) announces data in the islanded power grid (1), such as its actual value and its maximum achievable value, and wherein the power source (4) of the islanded power grid (1) calculates its own target value based on the data of the corresponding other power sources (4) and the power load (5), and informs the corresponding other power sources (4) of the target value, wherein the first power supply module (6) determines the state of charge of its battery (8), and The operating point of its fuel cell (10) or its DC / DC converter (9) is controlled according to the state of charge of its battery (8), wherein when the state of charge of the battery (8) of the first power supply module (6) is lowered, the power of the fuel cell (10) of the first power supply module (6) is increased until the battery (8) of the first power supply module (6) changes to the state of charge, or until the fuel cell (10) of the first power supply module (6) has reached the power limit. The characteristic is that if this is insufficient to charge the battery (8) of the first power supply module (6), the operating state of the first power supply module (6) is changed so that the first power supply module is no longer available for grid power supply, and the battery (8) of the first power supply module (6) is charged to a predetermined state of charge, wherein, in parallel, the operating state of the second power supply module (7) is changed so that the second power supply module is available for grid power supply to meet the required grid load.

2. The method according to claim 1, wherein, As the battery (8) of the first power supply module (6) reaches its maximum charge limit, the operating state of the first power supply module (6) is set so that the first power supply module can supply power to the grid again.

3. The method according to any one of the preceding claims, wherein, The data of one electrical unit (3) is communicated to the other electrical units (3) in a time-controlled manner and periodically, and the electrical units (3) of the islanded power grid (1) are controlled based on the data and with the aid of the algorithms available to the electrical units (3).

4. The method according to any one of the preceding claims, wherein, The priority of the electrical unit (3) is dynamically adjusted.

5. The method according to claim 4, wherein, The method involves energy supply on board the ship and sets the priority by selecting a navigation configuration.

6. The method according to claim 4, wherein, The priority is defined using a priority list.

7. The method according to claim 4, wherein, The priority is adjusted based on the number of operating hours of the electrical unit (3).

8. The method according to any one of the preceding claims, wherein, Redundancy requirements are specified, and when they fall below a predetermined limit in the islanded power grid (1), the operating state of at least one unused power source (4) is changed so that the power source is available to supply power to the power grid to meet the required redundancy.

9. The method according to any one of the preceding claims, wherein, Machine learning is used to optimize the operating parameters of the electrical energy supply modules (6, 7).

10. An islanded power grid (1) comprising electrical conductors (2) and a plurality of electrical units (3) connectable via the electrical conductors (2), wherein the electrical units can be power sources (4) or electrical loads (5), The electrical energy source (4) includes a first electrical energy supply module (6) and a second electrical energy supply module (7). For the first electrical energy supply module and the second electrical energy supply module, energy can be provided directly by a storage battery (8), or by a fuel cell (10) through a DC / DC converter (8), or by both the storage battery (8) and the fuel cell (10). The electrical energy source (4) of the islanded power grid (1) is configured to supply energy to the other electrical energy sources (4) in the islanded power grid (1). The notification data, such as their respective actual values, reserves, and minimum target values, wherein the power loads (5) of the islanded grid (1) are respectively configured to notify data, such as their actual values ​​and their maximum achievable values, within the islanded grid (1), and wherein the power sources (4) of the islanded grid (1) are configured to calculate their own target values ​​based on data from the corresponding other power sources (4) and the power loads (5), and to inform the corresponding other power sources (4) of the target values, wherein the first power supply of the electricity The module (6) is configured to determine the state of charge of its battery (8) and control the operating point of its fuel cell (10) or its DC / DC converter (9) based on the state of charge of the battery (8), wherein when the state of charge of the battery (8) of the first power supply module (6) is lowered, the power of the fuel cell (10) of the first power supply module (6) is increased until the battery (8) changes to the state of charge, or until the fuel cell (10) has reached the power limit. The module is characterized in that if this is insufficient to charge the battery (8) of the first power supply module (6), the operating state of the first power supply module (6) is changed so that the first power supply module is no longer available for grid power supply, and the battery (8) of the first power supply module (6) is charged to a predetermined state of charge, wherein, in parallel, the operating state of the second power supply module (7) is changed so that the second power supply module is available for grid power supply to meet the required grid load.

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