Method for central controller of energy storage system and controller

Abstract

A method and a central controller for controlling a central controller of an energy storage system of two or more battery systems are presented, wherein at least one of the two or more battery systems has at least one operating limit. The method comprises, and the central controller is configured to: obtain information relating to the at least one operating limit from the at least one battery system; -based on said information, determining control parameters of said two or more battery systems, respectively, taking into account an estimate of how said at least one battery system having said at least one operational limit will exhibit over time when controlled by its control parameters; and-providing the control parameters to the two or more battery systems, respectively.

Description

Technical Field

[0001] Aspects of the invention relate to a method of a central controller of an energy storage system for controlling two or more battery systems, a central controller, a power plant comprising the central controller, and a computer program or a computer readable medium. Background Art

[0002] Energy storage systems are used in power generation and distribution systems to balance the supply and demand of electricity. Due to the difficulty in quickly adjusting the power production of power plants connected to the power grid, power plants often include energy storage systems for matching the power provided by the power plants with the power consumption of consumers connected to the power grid.

[0003] Thus, the energy storage system is used as an energy buffer in which the energy produced can be stored, for example, during periods of overproduction of power in the power plant, until it is distributed to the grid and consumed in the grid, for example during periods of underproduction of power. In other words, the energy storage system is used to ensure that there is a balance between the supply of electricity from the power plant and the consumption of electricity in the grid. The energy storage system is centrally controlled, for example, by active and reactive power references assigned to the energy storage system by a power plant controller (PPC). These active and reactive power references control the charging and discharging in the energy storage system.

[0004] Within the energy storage system, a plurality of battery systems are arranged for storing electrical energy. Each of these battery systems comprises at least one power conversion system unit, at least one battery module and at least one cooling system. The battery systems are controlled by control parameters provided by a central controller of the energy system. Such control parameters may include active and reactive power set points. Summary of the invention

[0005] The disadvantage of conventional energy storage solutions is that they focus on the peak levels and duration of the charging and discharging of the battery system. Moreover, the control of the battery systems of the energy storage system is usually based on the assumption that all battery systems are equal. Therefore, when the battery system is controlled by a central controller, the capabilities of the individual battery systems are not properly taken into account.

[0006] This results in that the battery systems comprised in the energy storage system are not always utilized to their full potential, which results in that the energy system as a whole has difficulty providing the requested power level, ie has difficulty supplying a power level corresponding to the power reference provided by the power plant controller.

[0007] It is an object of the present invention to provide a solution that alleviates or solves the disadvantages and problems of conventional solutions.

[0008] The above and other objects are solved by the subject-matter of the various aspects of the independent claims. Further advantageous embodiments of the invention can be found in the dependent claims.

[0009] According to a first aspect of the present invention, a method for a central controller of an energy storage system for controlling two or more battery systems is proposed, wherein at least one of the two or more battery systems has at least one operating limitation. The method comprises:

[0010] - obtaining information related to said at least one operating limitation from said at least one battery system;

[0011] - based on said information, determining control parameters of said two or more battery systems respectively taking into account an estimate of how said at least one battery system having said at least one operating limitation will behave over time when controlled by its control parameters; and

[0012] - providing the control parameters to the two or more battery systems respectively.

[0013] An advantage of the method according to the first aspect is that it enables the energy storage system to comply with the power request requested / required by the grid via the power plant controller, i.e. comply with the power requested / required by using the overall active and reactive power reference. The method estimates how a battery system with operational limitations (i.e. a faulty battery system) will behave now and in the future, and uses this estimate to utilize the battery system to its best capabilities. Thus, according to the method, a faulty battery system is used intelligently while taking into account its operational limitations, rather than not using a battery system with operational limitations at all (which would be the case in a conventional solution).

[0014] For example, if it is estimated that one battery system will experience a certain operational interruption at some time in the future due to its operational limitations, if it would be controlled normally, i.e. it would be controlled in the same way as the rest of the battery systems, then this particular battery can be controlled individually so that the operational interruption is avoided. However, the battery system is hereby utilized within its own operational limitations so that it may contribute its limited capacity to the overall functionality of the energy storage system.

[0015] Thus, the method according to the first aspect provides for customized utilization of individual battery systems with operational constraints, which can also be described as a non-binary assignment of control parameters. This is completely different from the conventional binary assignment of control parameters (in which faulty battery systems are simply not used). Therefore, battery systems are conventionally fully utilized or not utilized at all depending on their condition, i.e. using a binary assignment. Therefore, since in conventional solutions it is not fully explored how each individual battery system contributes to the energy storage system as a whole reaching the requested power level, the energy storage system and its battery system are conventionally not optimally utilized.

[0016] However, according to the first aspect, partially defective battery systems are partially utilized according to their limited capacity, i.e., customized / non-binary control parameter dispatching is achieved. Therefore, compared with conventional solutions, the energy storage system utilizing the method of the first aspect takes into account the individual conditions of each of the battery systems when determining and dispatching control parameters. Therefore, when controlling the battery system according to the "power plant perspective", by considering the current conditions of the individual battery systems, the maximum charging and discharging capacity from each of the battery systems may not be required, but the requested power of at least one faulty battery system may be customized according to its limitations. By performing such intelligent and optimized control of the individual battery systems, the overall capacity of the energy storage system is increased.

[0017] According to an embodiment of the method according to the first aspect:

[0018] - Determination of control parameters is performed such that at least one battery system having at least one operating limitation is controlled to be utilized only during one or more of a limited time period and a limited peak power.

[0019] Thus, at least one battery system having at least one operational limitation can be utilized such that the at least one battery system does not fail completely. For example, if at least one battery system is partially inoperable, by this embodiment the at least one battery system can be used during a short period of time to avoid rendering it completely inoperable. Thus, the at least one battery system is controlled such that it can contribute to the power supply without being damaged, for example without overheating.

[0020] According to an embodiment of the method according to the first aspect:

[0021] - the at least one operating limitation is associated with an at least partially failed cooling system of the at least one battery system; and

[0022] - Determination of the control parameters is performed such that overheating of the at least one battery system is avoided when the at least one battery system having the at least one operating limitation is controlled by its control parameters.

[0023] Thus, by determining the control parameters according to this embodiment, the at least one battery system can be utilized within its capabilities, i.e. it can be used during short periods of time when the temperature remains within safe and reasonable limits. Thereby, the at least one battery system can contribute to the power supply, i.e. it can help the energy storage system to provide the requested power, but still without the risk of overheating. Due to the intelligent determination of the control parameters, it takes into account how the at least one battery system will behave over time due to its at least partially failed cooling system, i.e. it takes into account how the temperature of the at least one battery system will develop over time when it is utilized.

[0024] According to an embodiment of the method according to the first aspect:

[0025] The control parameter is determined based on a model, wherein the model describes how the temperature of the at least one battery system will change over time as a function of its control parameter due to the at least partially failed cooling system.

[0026] By using the model, a robust and accurate estimate is made of how the at least one battery system will behave over time when controlled by its control parameters due to its at least partially failed cooling system. Thereby, customized and accurate control of the at least one battery system is possible, so as to optimally utilize the at least one battery system within its limited capabilities / capacity.

[0027] According to an embodiment of the method according to the first aspect, the model is used in one of the following groups:

[0028] - determining information related to said at least one operational limitation; and

[0029] - Determination of control parameters using information related to said at least one operating limit as input to a model.

[0030] Thus, the model can be used within at least one battery system to determine operating limit information and / or can be used within a central controller to determine control parameters. Since the model can be used in various parts of the system, implementation flexibility is provided for various determinations. Using the model for these determinations results in efficient and accurate control of two or more battery systems.

[0031] According to an embodiment of the method according to the first aspect:

[0032] - said at least one operating limitation is associated with said at least one battery system having a limited ability to provide active power; and

[0033] - performing said determination of said control parameters so that said at least one battery system having said at least one operating limitation is controlled to provide active power corresponding to its limited active power capability and so that at least one power conversion system unit of said at least one battery system is respectively controlled to provide reactive power.

[0034] Thereby, the requested reactive power is handled by the at least one battery system that failed. In order to provide reactive power, the at least one battery unit does not have to function, it is sufficient if the power conversion system unit functions. The other battery systems can then focus on providing the requested active power. Thereby, the energy storage system can provide an increased active power capacity.

[0035] According to an embodiment of the method according to the first aspect, the at least one battery system is used for static synchronous compensation.

[0036] The fault battery system thus processes reactive power, making it possible to quickly regulate the voltage in the grid.

[0037] According to an embodiment of the method according to the first aspect:

[0038] - Determination of control parameters is performed such that at least one battery system having at least one operating limitation is controlled to be deactivated in order to reduce auxiliary power consumption of the energy storage system.

[0039] By deactivating at least one faulty battery system (which may occur after it has been used within its operating limits), its auxiliary power consumption is reduced to zero. This reduces the total auxiliary power consumption of the energy storage system and makes more power available for supply to the grid.

[0040] According to an embodiment of the method according to the first aspect:

[0041] - Determination of control parameters is performed such that at least one battery system having at least one operating limitation is controlled to perform a battery condition test.

[0042] It is important to know the state of charge (SOC) and the state of health (SOH) of the battery cells of the battery system. Therefore, repeated testing of the battery system should be performed. According to this embodiment, the test is performed when at least one battery system has operating limitations anyway, so the test itself does not affect the capacity of the energy storage system. Therefore, since at least one battery system has a fault anyway and is therefore only used within its limited capabilities, the test can be performed without further reducing the capacity of the energy storage system.

[0043] According to an embodiment of the method according to the first aspect, the control parameters include one or more of the following group:

[0044] - Active power set point; and

[0045] - Reactive power set point.

[0046] According to this embodiment, active power set points and reactive power set points are provided from a central controller to two or more battery systems. Thus, the requested power demand can be distributed to and processed by multiple battery systems. This provides a flexible tree structure system including multi-level control between the central controller and the battery systems. Thus, the energy storage system can be expanded so that more battery systems are added and controlled using such active power set points and reactive power set points.

[0047] According to an embodiment of the method according to the first aspect, the information related to the at least one operating limitation comprises information related to one or more of the following group:

[0048] - the actual state of the at least one battery system;

[0049] - performance of a cooling system of the at least one battery system;

[0050] - consistency of the rack status of the battery cells of the at least one battery system;

[0051] - a venting condition of battery cells of the at least one battery system;

[0052] - the maximum active power capability of the at least one battery system;

[0053] - the condition of at least one power conversion system unit of said at least one battery system;

[0054] - the insulation status of the at least one battery system; and

[0055] - Thermal properties of the battery cells of the at least one battery system.

[0056] Thus, the information related to the at least one operating limitation may include information related to a plurality of different states and / or conditions in the battery system. Thereby, a correct estimate of how the at least one battery system with the at least one operating limitation will behave over time may be performed. In general, if more information is available for the estimate, this improves the quality of the estimate. Furthermore, at various moments / situations, various types of information lead to the most correct estimate, so it is advantageous to be able to base the estimate on various types of information. Thus, this embodiment provides a flexible estimate of performance with high accuracy.

[0057] According to an embodiment of the method according to the first aspect:

[0058] - The determination of control parameters for the two or more battery systems respectively takes into account at least one operational limitation of at least one battery system, providing a condition-based control parameter distribution of remaining useful power between the two or more battery systems over time.

[0059] This condition-based control parameter allocation / dispatching enables a faulty battery system to contribute limited capacity to the overall functionality of the energy storage system. Thus, customized utilization of individual battery systems with operational limitations is provided, resulting in an increase in the overall capacity of the energy storage system.

[0060] According to a second aspect of the present invention, a central controller of an energy storage system configured to control two or more battery systems is provided, wherein at least one of the two or more battery systems has at least one operating limitation. The central controller is configured to:

[0061] - obtaining information related to said at least one operating limitation from said at least one battery system;

[0062] - based on said information, determining control parameters of said two or more battery systems respectively taking into account an estimate of how said at least one battery system having said at least one operating limitation will behave over time when controlled by its control parameters; and

[0063] - providing (430) control parameters to the two or more battery systems respectively.

[0064] The central controller of the second aspect has advantages corresponding to those mentioned above for the method of the central controller according to the first aspect of the invention.

[0065] It should be understood that all embodiments described for the method aspects of the present invention are also applicable to the central controller aspects of the present invention. Therefore, all embodiments described for the method aspects of the present invention may be performed by a central controller, which may include one or more controllers, control units or control devices. Embodiments of the central controller have advantages corresponding to those mentioned above for the method and its embodiments.

[0066] According to a third aspect of the present invention, a power plant configured to provide electric power to an electrical grid is provided. The power plant comprises:

[0067] - one or more power generation units;

[0068] - two or more battery systems; and

[0069] -A central controller as described herein.

[0070] The power plant of the third aspect has advantages corresponding to those mentioned above with respect to the method of the central controller according to the first aspect of the invention and embodiments thereof.

[0071] According to a fourth aspect of the present invention, the above and other objects are achieved by a computer readable medium or a computer program comprising instructions, which, when executed by a computer, causes the computer to perform one or more of the methods according to any one of the aspects and embodiments disclosed above or below. The advantages of the computer program or computer readable medium according to the fourth aspect correspond to the advantages of the method according to the first aspect and its embodiments mentioned above or below.

[0072] According to one aspect of the present invention, the above-mentioned computer program and / or computer-readable medium is configured to implement the method and embodiments thereof described herein.

[0073] The above-mentioned features and embodiments of the method, the central controller, the power plant, the computer program and the computer-readable medium, respectively, may be combined in various possible ways to provide further advantageous embodiments.

[0074] Further advantageous embodiments of the method, the central controller, the power plant, the computer program and the computer-readable medium according to the invention as well as further advantages of embodiments of the invention emerge from the detailed description of embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] For illustrative purposes, aspects and embodiments of the present invention are described in more detail by way of example and with reference to the accompanying drawings, in which like reference numerals are used for like parts, and in which:

[0076] Figure 1 is a schematic diagram illustrating an example of a power plant in which aspects and embodiments of the present invention may be implemented;

[0077] Figure 2 is a schematic diagram illustrating an energy storage system in which aspects and embodiments of the present invention may be implemented;

[0078] Figure 3 is a schematic diagram illustrating an energy storage system in which aspects and embodiments of the present invention may be implemented;

[0079] Figure 4 is a flow chart illustrating a method according to a first aspect of the invention and some embodiments thereof;

[0080] Figure 5 is a schematic and functional description of example uses of some embodiments of the present invention;

[0081] Figure 6 is a schematic and functional description of example uses of some embodiments of the present invention;

[0082] Figure 7 is a schematic and functional description of example uses of some embodiments of the present invention;

[0083] Figure 8 is a schematic and functional description of example uses of some embodiments of the present invention;

[0084] Fig. 9 is a schematic diagram illustrating an embodiment of a central controller according to the second aspect of the present invention, in which the method according to any one of the aspects and embodiments described herein may be implemented. DETAILED DESCRIPTION

[0085] Figure 1 A non-limiting example of a power plant 100 is schematically illustrated, in which aspects and embodiments of the present invention may be implemented. The aspects and embodiments of the present invention may of course be implemented in any essential solution in which an energy storage system is used and are not limited to Figure 1 or implemented in a power plant.

[0086] The power plant 100 is arranged to provide electricity or electrical energy to an electrical grid 102. The power plant 100 includes one or more power generation units 103. According to some embodiments, the one or more power generation units 103 may include one or more of the following group: a wind turbine generator, a photovoltaic panel, and a fuel cell. The wind turbine generator, the photovoltaic panel, and the fuel cell may also be generally described as a power source 103 of the power plant 100, or a generator 103 of the power plant 100. The power plant 100 also includes an energy storage system 200 described in more detail below.

[0087] Power plant 100 may be connected or connectable to electrical grid 102 via point of common coupling (PCC) 104. For some embodiments, electrical grid 102 may be referred to as a utility grid, electrical grid, or electrical power network. For example, power plant 100 may be located offshore or on land.

[0088] The power plant 100 includes a control device 105 configured to control the power plant 100. According to some embodiments, the control device 105 may include or be referred to as a power plant controller (PPC). Figure 1 As schematically shown in FIG. 1 , a power plant controller 105 controls the power generation units 103 and the energy storage system 200. The energy storage system 200 may here be controlled by a power reference provided by the power plant controller, as will be explained in more detail below.

[0089] Figure 2A non-limiting example of at least a portion of an energy storage system 200 is schematically illustrated in which aspects and embodiments of the present invention may be implemented. However, aspects and embodiments of the present invention may be implemented in any energy storage system in nature and are not limited to Figure 2 The energy storage system shown in .

[0090] As an example, Figure 2 The energy storage system shown includes a first battery system 210, a second battery system 220, a third battery system 230, and a fourth battery system 240. As will be appreciated by those skilled in the art, the energy storage system 200 may include any number of two or more battery storage systems 210, 220, 230, 240. Each of the battery systems 210, 220, 230, 240 includes at least one power conversion system unit 213, 223, 233, 243 and at least one battery cell 212, 222, 232a-c, 242. As schematically illustrated, for example, in the first battery system 210, one battery cell 212 may be associated / coupled with one power conversion system unit 213. However, as schematically illustrated in the third battery system 230, two or more battery cells (here illustrated as three battery cells 232a, 232b, 232c) may also be associated / coupled with one power conversion system unit 233. In addition, although for reasons of readability, the battery cells 212 and 213 are shown schematically in FIG. 2 , the battery cells 212 and 213 are shown schematically in FIG. 2 . Figure 1 102, but the battery system may also include two or more power conversion system units, wherein each of the two or more power conversion system units may be associated / coupled with one or more battery cells. The power conversion system units 213, 223, 233, 243 including converters are arranged to convert DC power from the battery cells 212, 222, 232a-c, 242 into AC power to be provided to the electrical grid 102, and to charge and discharge the battery cells 212, 222, 232a-c, 242.

[0091] Each of the battery systems 210, 220, 230, 240 may further include a functional unit 214, 224, 234, 244, such as a cooling system, i.e. a thermal system arranged to regulate the temperature of the battery system 210, 220, 230, 240 so as to ensure safe operation. Each of the battery systems 210, 220, 230, 240 also includes a local controller 211, 221, 231, 241 configured to control the battery units 212, 222, 232a-c, 242, the power conversion system units 213, 223, 233, 243 and the functional units 214, 224, 234, 244.

[0092] The energy storage system 200 also includes a central controller 260 configured to control each of the battery systems 210, 220, 230, 240. The central controller is provided with active and reactive power reference points Pref, Qref originating from the power plant controller 105. The central controller 260 may also be provided with information related to measurements in the power grid 102, for example including information related to one or more of active power P, reactive power Q, voltage V, current I, and frequency f measurements. The central controller 260 may also be provided with information from the battery systems 210, 220, 230, 240, including information related to one or more of the state of health (SOH), state of charge (SOC), mode state (M), apparent power availability, and active power availability of the respective battery systems 210, 220, 230, 240. Based on these inputs, i.e. based on its available information, the central controller determines the set points P1, Q1; P2, Q2; P3, Q3; P4, Q4 and distributes them to the battery systems 210, 220, 230, 240, respectively. Thus, each of the battery systems 210, 220, 230, 240 is provided with an individual set point from the central controller 260. In this document, the P set points P1, P2, P3, P4, P5 mentioned may be active power set points, and the Q set points Q1, Q2, Q3, Q4, Q5 mentioned may be reactive power set points. Thus, the functions of each of the battery systems 210, 220, 230, 240 are controlled by the central controller. The central controller 260 may be at least partially included / incorporated in the power plant controller 105. The central controller may also be arranged at least partially separately from the power plant controller and then controlled by the power plant controller 105 via the reference points Pref, Qref.

[0093] According to some embodiments, the central controller 260 is configured to control any controllable unit within the battery systems 210, 220, 230, 240. This may be, for example, the smallest controllable unit of the battery systems 210, 220, 230, 240, such as the battery systems 210, 220, 230, 240 themselves, the central power conversion system unit 213, 223, 233, 243 of the battery systems, or a plurality of distributed power conversion units of the battery systems. Thus, there may be one or more controllable units within each of the battery systems 210, 220, 230, 240, and the central controller 260 is configured to control these controllable units.

[0094] Figure 3A somewhat more detailed non-limiting example of an embodiment of a central controller 260 and some of the battery systems 210, 220, 230, 240, 250 in the energy storage system 200 is schematically illustrated. In this example, the central controller 260 is arranged in an electrical management system EMS 270 that may be at least partially included in the power plant controller 105. The electrical management system 270 also includes an active power controller 271 and a reactive power controller 272.

[0095] The active power controller 271 obtains an active power plant reference from the power plant controller 105 and an active power maximum reference from the central controller 260. Correspondingly, the reactive power controller 272 obtains a reactive power plant reference from the power plant controller 105 and a reactive power maximum reference from the central controller 260. The active and reactive power plant references are distributed to all corresponding electrical management systems in the power plant 100. The active power controller 271 and the reactive power controller 272 also obtain grid measurements related to one or more of active power, reactive power, and frequency. Based on these inputs, the active power controller 271 calculates an active power reference Pref, and the reactive power controller 272 calculates a reactive power reference Qref, which are provided to the central controller 260.

[0096] The central controller controls two or more schematically illustrated battery systems 210, 220, 230, 240, 250, wherein the combination Figure 1 A first battery system 210, a second battery system 220, a third battery system 230, and a fourth battery system 240 are described. Figure 3 In the example shown, the fifth battery system 250 includes four power conversion system units 253a, 253b, 253c, 253d. Each of the four power conversion system units 253a, 253b, 253c, 253d can be associated / coupled with one or more battery units (not shown). The fifth battery system 250 also includes at least one functional unit (not shown), such as at least one cooling system, and a local controller (not shown) configured to control the power conversion system, the battery unit, and at least one functional unit.

[0097] The central controller 260 can control the battery systems 210, 220, 230, 240, 250, as described above. Figure 2As described. Therefore, based on the active power reference Pref and the reactive power reference Qref and other inputs obtained by the central controller 260, the central controller 260 determines and provides individual set points P1, Q1; P2, Q2; P3, Q3; P4, Q4; P5, Q5 to the battery systems 210, 220, 230, 240, 250, respectively. Therefore, each of the battery systems 210, 220, 230, 240, 250 is provided with an individual set point P1, Q1; P2, Q2; P3, Q3; P4, Q4; P5, Q5 from the central controller 260, so that the function of each of the battery systems 210, 220, 230, 240, 250 is controlled by the central controller 260, and the central controller 260 is in turn controlled by the power plant controller 105.

[0098] As mentioned above, the present invention is described and schematically illustrated in Figure 2 and Figure 3 In the embodiment, the battery systems 210, 220, 230, 240, 250 each include at least one local controller, one or more power conversion system units and at least one battery cell. The battery systems 210, 220, 230, 240, 250 may also include at least one functional unit. Each of the one or more power conversion units may be associated with at least one battery cell. For example, the battery systems 210, 220, 230, 240, 250 may correspond to a battery energy storage system (BESS) unit or may be included in a battery energy storage system (BESS) unit, which may be located in a container, for example. The central controller 260 is configured to control the battery systems 210, 220, 230, 240, 250 by controlling the controllable units of the battery systems 210, 220, 230, 240, 250 (e.g., each of the battery systems) or one or more power conversion system units within each battery system.

[0099] Typically, a control system arranged to control the battery systems 210, 220, 230, 240, 250 receives power reference values ​​from a grid operator of the grid. The control system then controls the battery systems 210, 220, 230, 240, 250 based on these power reference values, wherein the control may utilize one or more controllers. Thus, the control system may include one central controller, or may include a series of two or more controllers arranged to control the battery systems 210, 220, 230, 240, 250.

[0100] The power plant controller (PCC) and energy management system (EMS) mentioned herein may operate at the same logical level in the control system, have at least partially different inputs and provide information to each other. For example, the power plant controller may generate an internal park reference, which is then split and sent to various assets / entities in the park, such as to two or more energy management systems in the park. For example, Figure 3 The active (P Plant Reference) and reactive (Q Plant Reference) power plant references at the top can be the reference / setpoints for this split. Each energy management system can then include a hierarchy of one or more internal controllers that will send information and commands to each other in order to comply with the received reference / setpoints.

[0101] Figure 4 A flow chart of a method according to a first aspect of the present invention is shown. The method discloses how a central controller 260 controls two or more battery systems 210, 220, 230, 240 when at least one of the two or more battery systems (e.g., the second battery system 220) has at least one operating limitation. Thus, at least one 220 of the two or more battery systems 210, 220, 230, 240 at least partially fails or fails, for example, due to at least one functional unit 214, 224, 234, 244 not functioning / operating properly.

[0102] In a first step 410, the central controller obtains information M related to at least one operating limitation. The information M is provided by at least one battery system 220 having an operating limitation. For example, if a functional unit 224 of the second battery system 220 fails, i.e., is faulty in some way, the local controller 221 of the second battery system 220 provides information about the operating limitation to the central controller 260. The operating limitation may also be related to the battery system 220 as a whole or to one or more parts of the battery system 220 (e.g., at least one power conversion system unit 223 and / or at least one battery unit 222). The operating limitation of at least one battery system 220 may change over time, depending on many factors, such as the type of operating limitation, ambient temperature, or other operating conditions. During a period of one or more hours, or even during a period of less than one hour, the condition of the battery system 220 may change, resulting in a changed operating limitation. The information related to at least one operating limitation may, for example, be included in a mode status report M provided to the central controller 260 from the second battery system 200 (e.g., Figure 2 and Figure 3 The mode status report M may, for example, include one or more of an error indication, a ready indication, a start indication, an operation indication, and an operation limit indication.

[0103] In a second step 420, the central controller 260 determines control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4, such as active power set points and reactive power set points, of two or more battery systems 210, 220, 230, 240, respectively, based on information M related to at least one operating limit. Figure 2 In the example shown, a first individual control parameter P1, Q1 is determined for the first battery system 210, a second individual control parameter P2, Q2 is determined for the second battery system 220, a third individual control parameter P3, Q3 is determined for the third battery system 230, and a fourth individual control parameter P4, Q4 is determined for the fourth battery system 240. The determination of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 is based on an estimate of how at least one battery system 220 with at least one operating limitation will behave over time when controlled by its control parameters P2, Q2. Therefore, if at least one faulty battery system 220 is to be controlled by utilizing its control parameters P2, Q2, it is predicted how at least one faulty battery system 220 will behave now and in the future. This prediction then forms the basis for determining the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 for two or more battery systems 210, 220, 230, 240. As understood by those skilled in the art, in addition to the information M related to the operating restrictions, the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 are also determined based on the above combined Figure 2 and 3 One or more of the inputs to the mentioned central controller.

[0104] In a third step 430, the determined control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 are provided to two or more battery systems 210, 220, 230, 240, respectively. Thus, each of the two or more battery systems 210, 220, 230, 240 is provided with their respective control parameters. These control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 are then used by the local controllers 211, 221, 231, 241 in each of the battery systems 210, 220, 230, 240 to control one or more of the power conversion system units 213, 223, 233, 243, the battery units 212, 222, 232a-c, 242, and the functional units 214, 224, 234, 244.

[0105] Thereby, i.e. by taking into account an estimate / prediction of how at least one faulty battery system 220 will behave when controlled by its control parameters, a customized use of the faulty battery system 220 is possible. Thus, the faulty battery system can then be used within its operating limitations, which results in an overall more optimized use of the battery system.

[0106] As explained in more detail below, the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 may include an active power set point P and a reactive power set point Q. These active P and reactive Q power set points are used to control the charging and discharging of the battery systems 210, 220, 230, 240 (i.e., the battery cells included in the battery systems 210, 220, 230, 240). These set points may have positive or negative values.

[0107] A positive reactive set point controls / provides charging of the battery systems 210, 220, 230, 240, while a negative reactive set point controls / provides discharging of the battery systems 210, 220, 230, 240. For example, if reactive power is leading, a positive reactive set point provides reactive power to the battery systems 210, 220, 230, 240, while a negative reactive set point consumes reactive power from the battery systems 210, 220, 230, 240 (i.e., if reactive power is lagging).

[0108] Figure 5-8 Schematic and functional illustration of examples of how some embodiments of the present invention may be used in the event of a fault in one 220 of the battery systems 210, 220, 230, 240. In these figures, the requested power over time is illustrated as a curve, represented in the figure as corresponding to the active and reactive power reference points "Pref, Qref" originating from the power plant controller 105, divided into four curves "P1, Q1"; "P2, Q2"; "P3, Q3"; "P4, Q4", each curve illustrating the requested power over time corresponding to the active and reactive power set points P1, Q1; P2, Q2; P3, Q3; P4, Q4 requested / required by the central controller 260 from the four battery systems 210, 220, 230, 240, respectively. Therefore, Figure 5-8 Schematically and functionally illustrates how the common power request Pref, Qref of the energy storage system is divided into individual power set points P1, Q1; P2, Q2; P3, Q3; P4, Q4 of the battery systems 210, 220, 230, 240, respectively. In other words, it illustrates how the common power request Pref, Qref is distributed over the battery systems 210, 220, 230, 240.

[0109] As an example, Figure 5-8 Four battery systems 210, 220, 230, 240 are illustrated, one of which 220 is at least partially faulty. However, as will be appreciated by those skilled in the art, the principles illustrated in these figures are readily extended to the more general aspects and embodiments described herein, wherein more than four battery systems (more than one of which may be faulty) may be controlled by a central controller 260.

[0110] according to Figure 5 In the illustrated embodiment, the central controller 260 takes into account an estimate of how at least one battery system 220 having at least one operational limitation will behave over time when controlled by its control parameters P2, Q2, so that the faulty battery system 220 is controlled to be utilized within its limitations. Thus, a determination 420 of the control parameters / set points P1, Q1; P2, Q2; P3, Q3; P4, Q4 is performed so that at least one battery system 220 having at least one operational limitation is controlled to be utilized only for limited time periods and / or during limited peak powers. Thus, the faulty battery system 220 is only temporarily / intermittently utilized when it is really needed, for example to operate at peak power (such as Figure 5 shown) and provides short power boosts within its operating limits.

[0111] The faulty battery system 220 is then controlled so that it can contribute to the overall power supply without, for example, the risk of overheating the faulty battery system 220. The central controller 260 also determines the control parameters, i.e., determines the active and reactive power set point groups P1, Q1; P3, Q3; P4, Q4 of the other battery systems 210, 230, 240 so that the remaining requested power (i.e., the total requested power "Pref, Qref" minus the power portion controlled by its control parameters P2, Q2 to the faulty battery system 220) is divided among the other battery systems 210, 230, 240.

[0112] Conventionally, in conventional systems, the central controller 260 would not use the faulty battery system 220 at all, but would instead divide the total requested power “Pref, Qref” over time into three substantially equal distribution curves illustrating the requested power “P1, Q1”; “P3, Q3”; “P4, Q4” over time on the other battery systems 210, 230, 240. Thus, three groups of control parameters, i.e., three groups of active and reactive power set points P1, Q1; P3, Q3; P4, Q4, would conventionally be assigned substantially the same values, each corresponding to one third of the total requested power, and the faulty battery system 220 would not be used at all. Clearly, embodiments of the present invention provide for more efficient use of the available battery systems 210, 220, 230, 240, and in particular the faulty battery system 220.

[0113] According to one embodiment, at least one operating limitation of the faulty battery system 220 is associated with an at least partially failed cooling system 224. Thus, the functional unit 224 of the faulty battery system 220 is here a non-functioning cooling system, ie a temperature regulation system.

[0114] The information M provided to the central controller 260 by the at least one battery system 220 is then related to the operating limits of the faulty cooling system 224. Thereby, the central controller 260 obtains information related to the way in which the cooling system 224 is faulty / failed / inoperable and possibly also related to how this affects the temperature regulation of the battery system 220 (i.e. how it affects the cooling performance of the cooling system 224).

[0115] The central controller 260 utilizes this operational limit information M as a basis for determining 420 control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 of two or more battery systems 210, 220, 230, 240. Thus, the determination 420 of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 may be performed such that overheating of at least one battery system 220 having at least one operational limit is avoided when it is controlled by its control parameters P2, Q2. Since the central controller may then base the determination of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 on an estimate / prediction of how the cooling system 224 and, therefore, the battery system 220 will behave over time due to its control parameters P2, Q2, the use of the battery system may be controlled such that its temperature becomes close to, but does not exceed, the maximum allowed temperature Tmax. Alternatively, the temperature may be intentionally controlled to exceed the maximum allowed temperature Tmax, but in a strictly regulated and safe manner.

[0116] In other words, because the central controller 260 knows how the faulty battery system 220 will behave, it can also utilize and use the faulty battery system within its limitations so that, although the faulty battery system remains operational, it does not cause undesirable overheating. This can be achieved by utilizing the faulty battery system 220 only for short periods of time and / or at peak power, such as Figure 5 As shown. Thereby, an optimal and robust use of the battery system 220 with operational limitations is achieved.

[0117] According to one embodiment, the determination 420 of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 for the battery systems 210, 220, 230, 240, respectively, is based on a model, i.e., a model-based determination. The model describes how the temperature of the faulty battery system 220, as a result of the at least partially failed cooling system 224, will change over time according to its control parameters P2, Q2. Thus, the model may include information related to the thermal behavior of the abnormal battery system 220. The model may be used to estimate the present and future behavior of the faulty battery system 220 when the faulty battery system 220 is controlled by its control parameters (i.e., by its active power set point P2 and reactive power set point Q2). Thus, according to one embodiment, the model is used to determine how the at least partially faulty battery system can still be utilized regardless of its operating limitations.

[0118] According to various embodiments, the model may be in the form of a statistically developed model, a laboratory developed model, a physical model, a lookup table, a graph, or substantially any other type of thermal representation that indicates how the temperature of the battery system varies over time as a function of its control parameters P2, Q2. The model may be determined based on measurements of the normal behavior of the battery system and measurements of its behavior when it has at least one operating limitation (e.g., when its cooling system 224 is faulty).

[0119] According to one embodiment, the model can be used by the central controller 260 to determine 420 control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4, wherein the obtained information M related to at least one operating limit is used as input to the model. According to other embodiments, the model can also be used to determine the information M related to at least one operating limit, wherein the model is used at least in the local controller 221 of the faulty battery system 220.

[0120] As a non-limiting numerical example, it can be mentioned that if a battery system with a normally functioning cooling system can operate at a power P for 60 minutes, the faulty system battery can operate at a power P for 17 minutes. If a normally functioning battery system can operate at twice the power 2P for 28 minutes, the faulty system battery can operate at this power 2P for 6 minutes. If a normally functioning battery system can operate at three times the power 3P for 12 minutes, the faulty system battery can operate at this power 3P for 1 minute. These are merely non-limiting numerical example values ​​used to illustrate, for example, the knowledge of the central controller included in the model, which is utilized when determining 420 control parameters to ensure that the faulty battery system can be safely utilized, but not utilized to the point of overheating it.

[0121] Figure 6 1 is a schematic and functional illustration of an example of how an embodiment of the present invention may be used in the event of a fault in one of the battery systems 210, 220, 230, 240, wherein the fault is associated with a limited ability of the battery system 220 to provide active power. It is illustrated how the requested power over time, denoted as “Pref, Qref” (including active power and reactive power), is distributed over the four battery systems 210, 220, 230, 240 by the central controller 260 according to the embodiment.

[0122] According to this embodiment, the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 of the battery systems 210, 220, 230, 240 are determined so that the battery system 220 having a limitation on providing active power is controlled by its control parameters P2, Q2 to provide active power corresponding to its limited active power capability. In addition, the power conversion system unit 223 of the battery system 220 is further controlled to provide reactive power. As is well known to those skilled in the art, reactive power can be used to control the voltage level of power in the power grid, while active power can be used to control the frequency of power in the power grid.

[0123] exist Figure 6 In the example shown, the faulty battery system 220 cannot provide active power at all. Therefore, the control parameters P2, Q2 of the faulty battery system 220 control the faulty battery system to provide only reactive power of the requested power. Therefore, the reactive power set point Q2 provided to the faulty battery system 220 from the central controller 260 corresponds to the requested reactive power reference Qref provided to the central controller 260 and originating from the power plant controller 105.

[0124] Thus, the faulty battery system 220 may, for example, be responsible for all requested reactive power, such as in Figure 6 In the diagram of . According to one embodiment, the faulty battery system 220 is used here as a static synchronous compensation. When the faulty battery system 220 is responsible for the requested reactive power, the other battery systems 210, 230, 240 are free to handle the requested active power, which may result in a higher overall active power capability of the energy storage system 200.

[0125] Figure 6 is an illustration of how this embodiment may be implemented. An alternative implementation would be to combine this embodiment with Figure 5 Then, the reactive power can be controlled by the central controller 260 so that it is Figure 5 The peak power burst provided by the fault battery system 220 is provided after that. Figure 5 Then a curve illustrating reactive power will be added after the peak in the "P2, Q2" curve.

[0126] Figure 7 1 is a schematic and functional illustration of an example of how an embodiment of the present invention can be used in the event of a fault in one of the battery systems 210, 220, 230, 240. It is illustrated how the requested power over time, denoted as "Pref, Qref", is distributed over the four battery systems 210, 220, 230, 240 by the central controller 260 according to this embodiment.

[0127] According to this embodiment, the determination 420 of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 is performed so that the faulty battery system 220 is controlled to be deactivated in order to reduce the auxiliary power consumption of the energy storage system 200. Figure 7 The zero value curve “ P2 , Q2 ” of the faulty battery system 220 is shown in FIG.

[0128] Therefore, after the faulty battery system 220 has been used within its operating limits and is thereafter selected to no longer be used in the energy storage system 200, the faulty battery system 220 should be deactivated. By deactivating the faulty battery system 220, i.e., by shutting down the faulty battery system 220, its power consumption is reduced to zero. Thus, for the faulty battery system 220, the total auxiliary power consumption (e.g., the power consumption of the local controller 221, the cooling system 224, the power conversion system unit 233, and other possible parts of the battery system) is reduced to zero. Basically, all auxiliary power that would otherwise be consumed by monitoring and surveillance and by power used to energize the transformer, etc. in the faulty battery system 220 can then be supplied to the grid 102 instead.

[0129] Figure 8 1 is a schematic and functional illustration of an example of how an embodiment of the present invention can be used in the event of a fault in one of the battery systems 210, 220, 230, 240. It is illustrated how the requested power over time, denoted as "Pref, Qref", is distributed over the four battery systems 210, 220, 230, 240 by the central controller 260 according to this embodiment.

[0130] According to this embodiment, the determination 420 of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 is performed so that the faulty battery system 220 is controlled by its control parameters, i.e. by its active power set point P2 and reactive power set point Q2, to perform a battery condition test, i.e. a test of at least one of its one or more battery cells 222. This is Figure 8 The test curve "P2, Q2" formed by the sawtooth of the faulty battery system 220 is schematically illustrated in FIG. The other battery systems 210, 230, 240 are controlled to process the requested active power and reactive power. Therefore, the requested active and reactive power references "Pref, Qref" are divided on the other non-faulty battery systems 210, 230, 240 by their corresponding control parameters (i.e., by their corresponding active and reactive power set points P1, Q1; P3, Q3; P4, Q4), so that the energy storage system 200 can provide the required active and reactive power "Pref, Qref".

[0131] Testing of the battery condition, followed by updating and calibration based on the test, is very important in any battery system. Typically, a battery condition test is performed so that the state of charge (SOC) and / or state of health (SOH) is determined for at least one of the one or more battery cells 222 of the faulty battery system 220. The battery condition test may include battery analysis under controlled conditions, such as by providing a well-defined / controlled current to the battery cell 222, where the current is independent of the required active and reactive power "Pref, Qref". Here, the faulty battery system 220 may be controlled, for example, by its active power set point P2 and reactive power set point Q2 to perform tests related to the above-mentioned model. Therefore, the model may be determined during the test controlled according to this embodiment.

[0132] According to some embodiments, the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 mentioned in this document for controlling the battery systems 210, 220, 230, 240, respectively, include active power set points and / or reactive power set points. Essentially, any control signal representation (such as control parameters, control signals, set points, reference values ​​and / or references) can be used for these control parameters, as long as the representation is used according to the definitions proposed herein. Therefore, the control parameters are used by a central controller 260 (essentially at any level in the energy storage system 200) to control two or more battery systems 210, 220, 230, 240, each battery system including one or more power conversion system units 213, 223, 233, 243 associated with at least one battery cell 212, 222, 232a-c, 242 and at least one local controller 211, 221, 231, 241. The battery system 210 , 220 , 230 , 240 may further include at least one functional unit 214 , 224 , 234 , 244 , such as a cooling system or the like.

[0133] According to various embodiments, the information M related to at least one operating limitation (i.e., information provided to the central controller 260 from the battery systems 210, 220, 230, 240) includes information related to the actual state of at least one battery system 220, such as the performance of the cooling system 224, the consistency of the rack state of the battery cells 222 (i.e., the state of individual batteries in a rack of multiple batteries) and / or the venting condition of the battery cells (i.e., degraded batteries emitting combustible gases).

[0134] According to further embodiments, the information M may also include information related to the maximum active power capability of at least one battery system 220, such as the condition of at least one power conversion system unit 223 of at least one battery system 220, the thermal properties of the battery unit 222 and / or the insulation state of at least one battery system 220, which may be reported by an insulation monitoring / measuring device.

[0135] According to one embodiment, the determination 420 of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 for two or more battery systems 210, 220, 230, 240, respectively, may also be based on the state of charge (SOC) and / or state of health (SOH) of the battery cells 212, 222, 232a-c, 242. Thus, consistent or inconsistent state of charge may be achieved by utilizing or excluding certain battery systems / cells or components of certain battery systems / cells. In addition, consistent state of health degradation of the energy storage system 200 may be achieved by excluding certain battery / system cells or components of certain battery cells.

[0136] Thus, the above-described determination 420 of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 for two or more battery systems 210, 220, 230, 240, respectively, provides a condition-based allocation of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 to the two or more battery systems 210, 220, 230, 240. The actual condition of the faulty battery system and how the condition will affect the battery system over time are determined by taking this determination 420 into account in the distribution. Thanks to this condition-based allocation, the remaining useful power to be provided by the two or more battery systems 210, 220, 230, 240 over time is divided between the two or more battery systems 210, 220, 230, 240 while exploring at least one operating limit of at least one faulty battery system 220.

[0137] According to a second aspect of the present invention, a central controller 260 of an energy storage system 200 is proposed. The central controller 260 is configured to control two or more battery systems 210, 220, 230, 240, wherein at least one battery system 220 has at least one operating limitation. For example, a faulty battery system 220 may have a functional unit 224 (such as a cooling system), a battery unit 222, or a power conversion system unit 223 that does not function properly, for example, fails or is at least partially defective in any way.

[0138] When at least one battery system 220 at least partially fails, the central controller 260 is configured to obtain 410 information M related to at least one operating limit from the at least one battery system 220 , as described in detail above.

[0139] The central controller 260 is also configured to determine 420 control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 of two or more battery systems 210, 220, 230, 240, respectively, based on the obtained information M. This determination of the control parameters P1, Q1; P2, Q2; P3, Q3; P4, Q4 takes into account an estimate of how at least one battery system 220 having at least one operating limitation will behave over time when controlled by its control parameters P2, Q2, as explained in detail above.

[0140] The central controller 260 is also configured to provide 430 control parameters P1 , Q1 ; P2 , Q2 ; P3 , Q3 ; P4 , Q4 to two or more battery systems ( 210 , 220 , 230 , 240 ), respectively.

[0141] according to Figure 1 In a third aspect of the invention, which is partially illustrated in FIG. 1 , a power plant 100 is proposed. The power plant is arranged / configured to provide the power generated in the power plant to an electrical grid 102. The power plant 100 comprises one or more power generation units 103, two or more battery systems 210, 220, 230, 240 and a central controller 260 configured to control the two or more battery systems 210, 220, 230, 240 as described herein.

[0142] Those skilled in the art will appreciate that the method aspects and embodiments described herein for controlling a central controller 260 of two or more battery systems 210, 220, 230, 240 may also be implemented in a computer program that, when executed in a computer, instructs the computer to perform the method. The computer program is typically comprised of a computer program product 503 stored on a non-transitory / non-volatile digital storage medium, wherein the computer program is incorporated into a computer-readable medium of the computer program product. The computer-readable medium includes a suitable memory, such as: ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable PROM), flash memory, EEPROM (electrically erasable PROM), hard disk unit, etc.

[0143] Fig. 9An embodiment of a central controller 260 according to an aspect of the invention is schematically shown, which may include a control unit 500, which may be arranged / configured to perform / implement one or more of the above method steps 410, 420, 430. The control unit 500 may include a computing unit 501, which may be constituted by essentially any suitable type of processor or microcomputer, such as a circuit for digital signal processing (digital signal processor, DSP) or a circuit with a predetermined specific function (application-specific integrated circuit, ASIC). The computing unit 501 is connected to a memory unit 502 arranged in the control unit 500. The memory unit 502 provides the computing unit 501 with, for example, stored program code and / or stored data, which the computing unit 501 needs in order to be able to perform calculations. The computing unit 501 is also arranged to store partial or final results of the calculations in the memory unit 502.

[0144] Furthermore, the control unit 500 may be provided with devices 511, 512, 513, 514 for receiving and transmitting input and output signals. These input and output signals may include waveforms, pulses or other properties, which may be detected as information by means of the devices 511, 513 for receiving input signals and may be converted into signals that can be processed by the computing unit 501. These signals are then made available to the computing unit 501. The devices 512, 514 for transmitting output signals are arranged to convert the signals received from the computing unit 501 so as to create output signals by, for example, modulating the signals, which output signals may, for example, be transmitted to the electrical grid 102 and / or the power plant 100 (see Figure 1 ) or other components and / or systems associated with electrical grid 102 and / or power plant 100. Each connection to a device for receiving and transmitting input and output signals may be comprised of one or more of a cable, a data bus, and a wireless connection.

[0145] In this and this document, a control unit is generally described as being provided for performing the steps of the method according to the various aspects and embodiments of the present invention described herein. This also includes that the unit is designed and / or configured to perform these method steps. For example, a control unit may include one or more control entities arranged to perform one or more of the method steps 410, 420, 430 described herein, respectively. These control entities may, for example, correspond to instruction groups, which may be in the form of programming codes, which are input into and utilized / executed by the processor / computing unit 501 of the control unit 500 when the entity is active and / or used to perform their method steps, respectively. Such control entities may be implemented as separate entities in multiple control units, or may be logically separated but physically implemented in the same control unit, or may be logically and physically arranged together.

[0146] Reference Figure 2 and Figure 3 The central controller 260, which may include one or more control units or control entities (e.g., one or more devices, controllers, or control devices), may be arranged to perform all method steps mentioned above, in the claims, and in connection with the various aspects and embodiments described herein. The central controller 260 is associated with the above advantages of each respective embodiment of the method.

[0147] The invention is not limited to the embodiments described above. On the contrary, the invention relates to and covers all different embodiments included within the scope of the independent claims.

Claims

1. A method for controlling a central controller (260) of an energy storage system (200) of two or more battery systems (210, 220, 230, 240), wherein: At least one battery system (220) of the two or more battery systems has at least one operating limitation, The method comprises: - obtaining (410) information (M) related to said at least one operating limitation from said at least one battery system (220); - based on the information (M), determining (420) control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) of the two or more battery systems (210, 220, 230, 240), respectively, taking into account an estimate of how the at least one battery system (220) having the at least one operating limitation will behave over time when controlled by its control parameters (P2, Q2); and - providing (430) the control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) to the two or more battery systems (210, 220, 230, 240), respectively.

2. The method according to claim 1, wherein: - performing determination (420) of said control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) such that said at least one battery system (220) having said at least one operating limitation is controlled to be utilized only during one or more of a limited time period and a limited peak power.

3. The method according to any one of claims 1 to 2, wherein: - the at least one operating limit is associated with an at least partially failed cooling system (224) of the at least one battery system (220); and - performing the determination (420) of the control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) so ​​that overheating of the at least one battery system (220) is avoided when the at least one battery system (220) having the at least one operating limitation is controlled by its control parameters (P2, Q2).

4. The method according to claim 3, wherein: - the control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) are determined (420) based on a model, wherein the model describes: due to the at least partial failure of the cooling system (224), 2022P00078WOCN (JAJNN) How the temperature of the at least one battery system (220) will change over time according to its control parameters (P2, Q2).

5. The method according to claim 4, wherein: The model is used in one of the following groups: - determining information (M) related to said at least one operating constraint; and - determining (420) said control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) using information (M) related to said at least one operating limit as input to said model.

6. The method according to any one of claims 1 to 5, wherein: - said at least one operating limitation is associated with said at least one battery system (220) having a limited ability to provide active power; and - performing determination (420) of the control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) such that the at least one battery system (220) having the at least one operating limitation is controlled to provide active power corresponding to its limited active power capability, and such that the at least one power conversion system unit (223) of the at least one battery system (220) is respectively controlled to provide reactive power.

7. The method according to claim 6, wherein: The at least one battery system (220) is used for static synchronous compensation.

8. The method according to any one of claims 1 to 7, wherein: - performing the determination (420) of the control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) so ​​that the at least one battery system (220) having the at least one operating limitation is controlled to be deactivated in order to reduce auxiliary power consumption of the energy storage system (200).

9. The method according to any one of claims 1 to 8, wherein: - performing the determination (420) of the control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) such that the at least one battery system (220) having the at least one operating limitation is controlled to perform a battery condition test.

10. The method according to any one of claims 1 to 9, wherein: The control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) include one or more of the following groups: - Active power set point; and - Reactive power set point.

11. The method according to any one of claims 1 to 10, wherein: The information (M) related to the at least one operational limitation comprises information related to one or more of the following group: - the actual state of the at least one battery system (220); - performance of a cooling system (224) of the at least one battery system (220); - consistency of the rack status of the battery cells (222) of the at least one battery system (220); - a venting condition of a battery cell (222) of at least one battery system (220); - the maximum active power capability of the at least one battery system (220); - a condition of at least one power conversion system unit (223) of said at least one battery system (220); - the insulation state of the at least one battery system (220); as well as - thermal properties of the battery cells (222) of the at least one battery system (220).

12. The method according to any one of claims 1 to 11, wherein: - Determination (420) of control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) for the two or more battery systems (210, 220, 230, 240), respectively, taking into account the at least one operating limitation of the at least one battery system (220), providing a condition-based control parameter distribution of remaining useful power between the two or more battery systems (210, 220, 230, 240) over time.

13. A computer readable medium or a computer program (503) comprising instructions which, when executed by a computer, cause the computer to perform one or more of the methods according to any one of claims 1 to 12.

14. A central controller (260) of an energy storage system (200) configured to control two or more battery systems (210, 220, 230, 240) 2022P00078WOCN (JAJNN), wherein: At least one battery system (220) of the two or more battery systems has at least one operating limitation, wherein the central controller (260) is configured to: - obtaining (410) information (M) related to said at least one operating limitation from said at least one battery system (220); - based on the information (M), determining (420) control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) of the two or more battery systems (210, 220, 230, 240), respectively, taking into account an estimate of how the at least one battery system (220) having the at least one operating limitation will behave over time when controlled by its control parameters (P2, Q2); and - providing (430) the control parameters (P1, Q1; P2, Q2; P3, Q3; P4, Q4) to the two or more battery systems (210, 220, 230, 240), respectively.

15. A power plant (100) configured to provide electrical power to an electrical grid (102), wherein: The power plant (100) comprises: - one or more power generation units (103); - two or more battery systems (210, 220, 230, 240); and - A central controller (260) according to claim 14.

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