Battery system management device and method for determining optimal number of batteries

Abstract

A battery system management apparatus according to one embodiment of the present invention may comprise: at least one processor; and a memory to store one or more instructions executed by the at least one processor. Here, the one or more instructions may include: instructions for defining an equivalent model of a battery system, the battery system including a plurality of batteries and at least one protection element and formed in a predetermined connection structure; calculating instructions to use the equivalent model to generate a short circuit current in the battery system when a short circuit occurs at a specific location in the battery system; an instruction to compare the calculated short-circuit current with a limiting current of the protection element; and an instruction to determine the number of batteries set in the battery system based on the comparison result.

Description

Technical Field

[0001] This application is based on and claims the benefit of priority from Korean Patent Applications No. 10-2023-0084787 and No. 10-2023-0113262 filed on June 30, 2023 and August 29, 2023, respectively, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety.

[0002] The present disclosure relates to a battery system management device. Background Art

[0003] Secondary batteries are batteries that can be repeatedly used by charging even after discharge, and can be used as energy sources for small devices such as portable phones, tablet PCs, and vacuum cleaners, and also as energy sources for medium and large devices such as automobiles and energy storage systems (ESS) for smart grids.

[0004] According to the requirements of the system, the secondary battery is applied to the system in the form of a component, such as a battery module in which a plurality of battery cells are connected in series and / or in parallel, or a battery pack in which battery modules are connected in series and / or in parallel. In the case of medium and large-sized equipment such as ESS for smart grids, a high-capacity battery system in which a plurality of battery racks are connected in parallel can be applied to meet the required capacity of the corresponding equipment.

[0005] Meanwhile, the number of batteries included in such a battery system may be adjusted according to, for example, the magnitude of a short-circuit current in the battery. In this regard, appropriate battery system management technology is required according to circumstances (see, for example, Korean Patent Laid-Open Publication No. 10-2010-0050514). Summary of the invention

[0006] Technical issues

[0007] The present disclosure provides a battery system management device for determining an optimal number of batteries provided in a battery system.

[0008] Furthermore, the present disclosure provides a battery system management method using the battery system management device.

[0009] Technical Solution

[0010] A battery system management device according to an embodiment of the present disclosure may include at least one processor and a memory storing at least one command to be executed by the at least one processor.

[0011] Here, the at least one command may include: a command for defining an equivalent model of the battery system, the battery system being configured to have a predefined connection structure including a plurality of batteries and at least one protection element; a command for using the equivalent model to calculate the short-circuit current generated in the battery system when a short circuit occurs at a certain location in the battery system by using the equivalent model while reflecting the time constant characteristics of the connecting elements according to the predefined connection structure; a command for comparing the calculated short-circuit current with the limiting current of the protection element; and a command for determining the number of batteries set in the battery system based on the comparison result.

[0012] The protection element may be provided at one or more of an input / output terminal of the battery, a connection point of the battery, and a connection point of the battery pack.

[0013] The command for defining the equivalent model may include a command for defining an equivalent model of the battery system based on a first equivalent model of the battery, a second equivalent model of the protection element, and a third equivalent model of a connection element electrically connecting the battery to an external device. Here, the third equivalent model may be defined as an RL equivalent circuit having a resistance value and an inductance corresponding to the length of the connection element.

[0014] The command to calculate the short circuit current may include a command to calculate the short circuit current applied to each of the plurality of protection elements by reflecting a time constant characteristic of the connection element according to the predefined connection structure when the short circuit occurs at one or more locations.

[0015] The location where the short circuit occurs includes at least one of the following: a first location, which is defined as a location inside the battery; a second location, which is defined as a location between the connection points between the batteries; a third location, which is defined as a location between the connection points of the batteries and the connection points of the battery pack; and a fourth location, which is defined as a location between the connection points of the battery pack and the power conversion system.

[0016] The command for comparing may include a command for identifying, for each of the plurality of protection elements, whether the short-circuit current exceeds a limit current defined based on a short-circuit capacity of the protection element.

[0017] The command for determining the number of batteries may include a command for determining a maximum number of batteries that prevents a short-circuit current applied to each of a plurality of protection elements from exceeding the limit current of each of the plurality of protection elements.

[0018] The command for calculating the short-circuit current may include: a command for calculating the short-circuit current applied to each of the plurality of protection elements by reflecting the time constant characteristic of the connection element according to the predefined connection structure for each case where a short circuit occurs at a plurality of locations. Here, the command for determining the number of batteries may include: a command for determining the maximum number of batteries that prevents the short-circuit current applied to each of the plurality of protection elements from exceeding the limit current of each of the plurality of protection elements for all of the cases.

[0019] The command for determining the maximum number of batteries may include: a command for redefining an equivalent model by changing the number of batteries included in the battery system according to a comparison result of the short-circuit current and the limit current; and a command for recalculating the short-circuit current based on the redefined equivalent model.

[0020] According to an embodiment, a method for managing a battery system with the aid of a battery system management device may include: defining an equivalent model of a battery system, wherein the battery system is configured to have a predefined connection structure including a plurality of batteries and at least one protection element; when a short circuit occurs at a certain location in the battery system, using the equivalent model to calculate the short-circuit current generated in the battery system by reflecting the time constant characteristics of the connecting elements according to the predefined connection structure and using the equivalent model; comparing the calculated short-circuit current with the limiting current of the protection element; and determining the number of batteries set in the battery system based on the comparison result.

[0021] The protection element may be provided at one or more of an input / output terminal of the battery, a connection point of the battery, and a connection point of the battery pack.

[0022] The step of defining the equivalent model may include defining the equivalent model of the battery system based on: a first equivalent model of the battery; a second equivalent model of the protection element; and a third equivalent model of a connection element electrically connecting the battery to an external device. Here, the third equivalent model may be defined as an RL equivalent circuit having a resistance value and an inductance corresponding to the length of the connection element.

[0023] The step of calculating the short circuit current may include calculating the short circuit current applied to each of the plurality of protection elements by reflecting a time constant characteristic of the connection element according to the predefined connection structure when the short circuit occurs at one or more locations.

[0024] The location where the short circuit occurs includes at least one of the following locations: a first location, which is defined as a location inside the battery; a second location, which is defined as a location between the connection points between the batteries; a third location, which is defined as a location between the connection points of the batteries and the connection points of the battery pack; and a fourth location, which is defined as a location between the connection points of the battery pack and the power conversion system.

[0025] The step of comparing may include: identifying, for each of the plurality of protection elements, whether the short-circuit current exceeds a limit current defined based on a short-circuit capacity of the protection element.

[0026] The step of determining the number of batteries may include determining a maximum number of batteries that prevents a short-circuit current applied to each of a plurality of protection elements from exceeding the limit current of each of the plurality of protection elements.

[0027] The step of calculating the short-circuit current may include: for each case where a short circuit occurs at a plurality of locations, calculating the short-circuit current applied to each of the plurality of protection elements by reflecting the time constant characteristic of the connection element according to the predefined connection structure. Here, the step of determining the number of batteries may include: for all of the cases, determining a maximum number of batteries that prevents the short-circuit current applied to each of the plurality of protection elements from exceeding the limit current of each of the plurality of protection elements.

[0028] The step of determining the maximum number of batteries may include: redefining an equivalent model by changing the number of batteries included in the battery system according to a comparison result of the short-circuit current and the limit current; and recalculating the short-circuit current based on the redefined equivalent model.

[0029] Beneficial Effects

[0030] According to the embodiments of the present disclosure as described above, by determining the optimal number of batteries included in the battery system using an equivalent model of the battery system, the design cost of the battery system can be minimized and the energy density of the battery system can be maximized, thereby enhancing product competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a block diagram of a general battery system.

[0032] Figure 2 (a) and Figure 2 (b) is used to illustrate Figure 1 A graph of the short-circuit current generated in a battery system.

[0033] Figure 3 is a block diagram of a battery system to which the present disclosure may be applied.

[0034] Figure 4 The present invention is an operational flow chart of a battery system management method according to an embodiment of the present invention.

[0035] Figure 5 is a block diagram for explaining an equivalent model of a battery system according to an embodiment of the present disclosure.

[0036] Figure 6 The present invention is a flowchart of a battery system management method according to another embodiment of the present invention.

[0037] Figure 7 is a circuit diagram for explaining an equivalent model of a battery according to an embodiment of the present disclosure.

[0038] Figure 8 and Fig. 9 is a diagram illustrating a battery system to which the present disclosure is applied.

[0039] Fig.10 The present invention is a flowchart of a battery system management method according to another embodiment of the present invention.

[0040] Fig.11 is a block diagram for explaining the simulation results of the first case.

[0041] Fig.12 is a block diagram for explaining the simulation results of the second case.

[0042] Fig.13 is a block diagram for explaining the simulation results of the third case.

[0043] Fig.14 is a block diagram for explaining the simulation results of the fourth case.

[0044] Fig.15 It is a block diagram for explaining the simulation results of the fifth case.

[0045] Fig.16 (a) and Fig.16 (b) is a block diagram for explaining the structure of a battery system derived according to the present disclosure.

[0046] Fig.17 is a block diagram of a battery system management device according to an embodiment of the present disclosure.

[0047] In the drawings, corresponding parts have the same reference numerals. It will be appreciated by those skilled in the art that the drawings simply and clearly illustrate the elements and are not necessarily drawn to scale. For example, to aid in understanding the various embodiments, the size of the elements shown in the drawings may be exaggerated compared to other elements. In addition, elements that are useful or necessary in commercially feasible embodiments but are known in the art may generally be omitted so as not to hinder the understanding of the ideas of the various embodiments of the present disclosure.

[0048] 100: Battery rack

[0049] 200: BCP

[0050] 300: PCS

[0051] 400: Battery system management device DETAILED DESCRIPTION

[0052] The present disclosure may be modified differently and may have various embodiments. Therefore, the embodiments will be illustrated in the drawings and described in detail in the detailed description. However, it should be understood that this is not intended to limit the present disclosure to the embodiments, and all modifications, equivalents and replacements fall within the spirit and scope of the present disclosure. In each of the drawings shown in the figure, the same reference numerals are used for the same elements.

[0053] Terms such as "first", "second", "A", and "B" may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component without departing from the scope of the present disclosure. The term "and / or" includes a plurality of related listed items or a combination of any items in the plurality of related listed items.

[0054] When a component is referred to as being "connected" or "coupled" to another component, it should be understood that the component may be directly connected or coupled to another element, but another component may exist between them. Conversely, when a component is referred to as being "directly connected" or "directly coupled" to another component, it should be understood that no other components exist between them.

[0055] The terms used herein are only used to describe specific embodiments and are not intended to limit the present disclosure. Unless the context clearly provides otherwise, singular expressions include plural expressions. In this article, it should be understood that terms such as "including" and "having" are intended to indicate the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the description, but are not intended to exclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0056] Unless otherwise defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. Terms (such as those defined in commonly used dictionaries) will be interpreted as having a meaning consistent with the meaning in the context of the relevant art, and will not be interpreted in an ideal or overly formal sense unless explicitly defined herein.

[0057] Some terms used herein are defined below.

[0058] A battery cell is the smallest unit for storing electricity, and a battery module refers to an assembly in which a plurality of battery cells are electrically connected.

[0059] A battery rack refers to a system with a minimum single structure that electrically connects module units set by a battery manufacturer and can be monitored and controlled by a battery management system (BMS), and may include multiple battery modules (or battery racks) and at least one battery protection unit (BPU) or protection device.

[0060] The battery pack may refer to a group of large-scale battery rack systems in each of which a plurality of battery racks are connected in parallel. Monitoring and control of a rack BMS (RBMS) in a battery pack unit may be performed by the BMS in the battery pack unit.

[0061] A battery assembly refers to an assembly that includes a plurality of electrically connected battery cells and is applied to a specific system or device to be used as a power source. Here, the battery assembly may refer to, for example, a battery module, a battery pack, a battery rack, or a battery bank, but the scope of the present disclosure is not limited to these entities.

[0062] The number of batteries included in the battery system is determined based on the magnitude of the short-circuit current in the battery and the short-circuit capacity of the protection element included in the battery system. For example, when the short-circuit current capacity of the protection element is 100 kA and the short-circuit current of the unit battery is 10 kA, the maximum number of parallel batteries is determined to be 10.

[0063] However, according to the method of determining the number of batteries, there is a problem that the total number of batteries provided in the battery system is unnecessarily limited. For example, the total short-circuit current of the battery system is affected by various factors, such as the connection structure between the batteries and the type and length of the cables connecting the various components. However, when the number of batteries is determined simply based on the magnitude of the short-circuit current in the battery and the short-circuit capacity of the protection element included in the battery system, the total short-circuit current of the battery system is calculated assuming that the short-circuit current of each battery is the same. Therefore, the total short-circuit current is estimated to be higher than the actual value. Therefore, the maximum number of batteries included in the battery system is unnecessarily limited, which will unnecessarily increase the design cost and lower energy density of the battery system. Therefore, there is a risk that product competitiveness will be weakened.

[0064] The present disclosure provides a battery management system capable of optimizing battery connection by predicting the short-circuit current of the battery.

[0065] Hereinafter, the present disclosure and various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0066] Figure 1 is a block diagram of a battery system 10 according to an embodiment of the present disclosure, and Figure 2 (A) and Figure 2 (B) is used to illustrate Figure 1 A graph of the short-circuit current generated in the battery system 10 is shown.

[0067] refer to Figure 1 , the battery system 10 may include a plurality of battery racks 100. Here, the plurality of battery racks 100 are connected in parallel to a battery control panel (BCP) 200, and the BCP 200 may be electrically connected to, for example, a battery control panel (BCP) 200 to be referred to later. Figure 3 A power conversion system (PCS) 300 is described.

[0068] Inside each battery rack 100 , a battery protection unit (BPU) 110 is provided, and the BPU 110 may include at least one protection element 110 (eg, a fuse and / or a switch device). In addition, at least one protection element 210 (eg, a fuse and / or a switch device) may be included in the BCP 200 .

[0069] For example, the number of battery racks 100 connected in parallel in the unit battery system 10 is determined based on the short-circuit capacity of the protection element and the magnitude of the short-circuit current. For example, when the short-circuit current capacity of the protection element 210 provided inside the BCP 200 is 100 kA and the short-circuit current applied to each battery rack 100 is 10 kA, it can be determined that the maximum number of battery racks 100 that can be included in the battery system is 10.

[0070] However, according to this method, there is a problem in that the total number of battery racks 100 provided in the battery system 10 is unnecessarily limited.

[0071] Figure 2 (A) shows a short-circuit current applied to each of a plurality of battery racks 100 (in this embodiment, five battery racks connected in parallel) when a short circuit occurs in the battery system, and Figure 2 (B) shows the total short-circuit current, which is the sum of the short-circuit currents of the plurality of battery racks 100 .

[0072] Likewise Figure 1As shown in the structure of the battery system 10, the installation positions of the corresponding battery racks 100 in the battery system 10 are different from each other, and the lengths of the cables for connecting to the corresponding battery racks 100 of the BCP may be different from each other. Figure 2 As shown in (A), due to the difference in time constants, the short-circuit current applied to the respective battery racks 100 reaches the maximum current value at different time points. Due to these differences in the time constants of the respective battery racks 100, the maximum value of the total short-circuit current becomes smaller than the sum of the maximum short-circuit current values ​​of the respective battery racks 100, as shown in FIG. Figure 2 (B) shown.

[0073] However, in the above-mentioned method of calculating the number of batteries, since the total short-circuit current of the battery system 10 is calculated assuming that the short-circuit currents of the respective battery racks 100 are the same, the total short-circuit current is estimated to be higher than the actual short-circuit current. Therefore, the number of battery racks 100 included in the battery system 10 is unnecessarily limited, which will unnecessarily increase the design cost of the battery system 10 and reduce the energy density, thereby weakening the product competitiveness.

[0074] Figure 3 2 is a block diagram of a battery system 20 to which an embodiment of the present disclosure is applied.

[0075] The battery system 20 according to the embodiment may include a plurality of battery racks 100, at least one BCP 200, and a power conversion system 300 (PCS). The battery rack 100 may be connected in parallel to each of the plurality of BCPs 200, and the BCP 200 may be connected in parallel to the power conversion system 300. Inside each battery rack 100, a BPU 110 and a battery management system (BMS) 120 may be provided. Here, for example, the BPU 110 may include at least one protection element (e.g., a fuse and / or a switching device). The BMS 120 may be a rack battery management system (RBMS).

[0076] At least one protection element 210 (e.g., a fuse and / or a switching device) may be included in the BCP 200. In addition, at least one protection element 310 (e.g., a fuse and / or a switching device) may be provided on a connection path between the PCS 300 and the BCP 200. In addition, the battery rack 100, the BCP 200, and the PCS 300 may be electrically connected to each other via the connection elements 130, 230. Here, the connection elements 130, 230 may be made of a conductive metal and include, for example, at least one of a cable and a bus bar.

[0077] Meanwhile, according to an embodiment, the battery system management device 400 may be connected to at least one of the BCPs 200. The battery system management device 400 may be installed inside each BCP 200, or may be connected to each BCP 200 from the outside of the BCP 200 via a wired connection or a wireless connection to manage the battery system.

[0078] Each protection element 110, 210, 310 included in the battery system 20 may have a predefined limiting current value. Here, the limiting current value may be defined as a value obtained by multiplying the short-circuit capacity of the protection element by a predefined adjustment constant K. For example, the adjustment constant K may be defined as a predetermined value of about 0.8 or more and about 1 or less. For example, when the short-circuit capacity of a particular protection element is 100 kA and the adjustment constant K is 0.95, the limiting current of the protection element may be defined as 95 kA (100 kA*0.95).

[0079] Figure 3 The structure of the battery system 20 shown is an example of the present disclosure, and the scope of the present disclosure is not limited to this structure. For example, a separate DC / DC converter instead of the BPU 110 may be applied to some or all of the battery racks 100, the battery rack 100 may be equipped with a separate DC / DC converter instead of the BPU 110, and the battery in the module or battery pack unit instead of the battery rack unit may be applied to the battery system 20.

[0080] Figure 4 4 is an operation flow chart of a battery system management method according to an embodiment of the present disclosure. The battery system management method according to the present disclosure may be executed by, for example, a battery system management device 400. The battery system management device 400 Fig.17 Shown in.

[0081] The battery system management device 400 may define an equivalent model of the battery system 20 ( S410 ).

[0082] According to an embodiment, the battery system may have a predetermined connection structure including a plurality of batteries and at least one protection element. Here, the protection element may be placed at one or more positions such as the input / output terminal of the battery, the connection point of the battery, and the connection point of the battery pack. Meanwhile, the battery may mean a battery cell or a battery assembly.

[0083] Figure 5 is a block diagram for explaining an equivalent model of the battery system 30 according to an embodiment of the present disclosure.

[0084] The battery system management device 400 may define an equivalent model of the battery system 30 corresponding to the structure of the actual battery system 20 .

[0085] For example, the battery system management device 400 may define an equivalent model of the battery system 30 including a total of N batteries and a power conversion system, such as Figure 5 Here, the M batteries connected in parallel may be defined as a first group, and the remaining batteries connected in parallel may be defined as a second group.

[0086] The position of the protection element can be defined to correspond to the position on the actual battery system. For example, the position of the protection element 210 can be defined as the input / output terminal A of each battery, the parallel connection point B of the battery, and the parallel connection point C of the battery pack.

[0087] For each protection element included in the equivalent model, a limiting current may be defined. Here, the limiting current may be defined as a value obtained by multiplying the short-circuit capacity of the actual protection element by a predefined adjustment constant K.

[0088] The battery system management device 400 may define an equivalent model of the entire battery system based on a first equivalent model of the battery, a second equivalent model of the protection element, and a third equivalent model of the connection element 130, 230 electrically connecting the battery to the external device. Here, the first equivalent model may be defined as an equivalent circuit including an internal resistance Ric and an internal inductance Lic according to the characteristics of the battery, the second equivalent model may be defined as an equivalent circuit including a resistance Rarc and a capacitance Carc according to the characteristics of the protection element and the switch, and the third equivalent model may be defined as an equivalent circuit including a resistance Rec and an inductance Lec according to the length and characteristics of the connection element 130, 230.

[0089] Return to reference Figure 4 The battery system management device 400 may use the equivalent model defined in S410 to calculate the short-circuit current generated in the battery system when a short circuit occurs at a certain location in the battery system (S420). For example, when a short circuit occurs inside the battery, the battery system management device 400 may calculate the short-circuit current generated at a certain location in the battery system.

[0090] When the battery system includes a plurality of protection elements, the battery system management device 400 may calculate the short circuit current applied to each protection element. For example, when a short circuit occurs inside the battery, the battery system management device 400 may calculate the short circuit current applied to each protection element included in the battery system.

[0091] The location where the short circuit occurs in the battery system may be predefined. Here, the short circuit occurrence location may include at least one of a first location defined as a location inside the battery, a second location defined as a location between the connection points of the battery and the battery pack, a third location defined as a location between the connection points of the battery and the battery pack, and a fourth location defined as a location between the connection points of the battery pack and the power conversion system. For example, Figure 5 In the present invention, the location where the short circuit occurs can be defined as at least one of the location inside the battery (P1), the location between the parallel connection points of the battery and the battery (P2), the location between the parallel connection points of the battery and the parallel connection points of the battery pack (P3), and the location between the parallel connection points of the battery pack and the power conversion system (P4).

[0092] When a short circuit occurs at each of a plurality of locations in the battery system, the battery system management device 400 may calculate a short circuit current generated in the battery system. For example, when a short circuit occurs at P1, the battery system management device 400 may calculate a short circuit current applied to each protection element, and when a short circuit occurs at P2, the battery system management device 400 may calculate a short circuit current applied to each protection element when a short circuit occurs at P2. As another example, when a short circuit occurs at both P1 and P2, the battery system management device 400 may calculate a short circuit current applied to each protection element.

[0093] The battery system management device 400 may compare the short-circuit current calculated in S420 with a limit current of a protection element included in the battery system ( S430 ).

[0094] In one embodiment, the battery system management device 400 may identify whether the short-circuit current exceeds the current limit of each protection element included in the battery system. For example, for all protection elements, the battery system management device 400 may compare the short-circuit current applied to each protection element with the current limit of each protection element, and may determine whether there is a protection element whose short-circuit current exceeds the current limit.

[0095] The battery system management device 400 may determine the number of batteries set in the battery system based on the comparison result in S430 (S440). Here, the battery system management device 400 may determine the number of batteries so that the short-circuit current applied to each protection element does not exceed the limiting current of each protection element. For example, when the short-circuit current applied to a specific protection element exceeds the limiting current of each protection element, the battery system management device 400 may determine that the corresponding protection element cannot withstand the short-circuit current and attempt to sequentially reduce the number of batteries. On the contrary, when the short-circuit current applied to the protection element is lower than the limiting current value of each protection element, the battery system management device 400 may determine that the corresponding protection element can withstand the short-circuit current, and may attempt to maintain the current state or sequentially increase the number of batteries.

[0096] In an implementation, the battery system management device 400 may determine the maximum number of batteries that allows all protection elements of the battery system to withstand the short-circuit current.

[0097] For example, the battery system management device 400 may perform simulation (S410 to S430) to calculate the short-circuit current of a battery system including N batteries. When all protection elements are identified as being able to withstand the short-circuit current (the short-circuit current is equal to or less than the limit current), the battery system management device 400 may simulate (S410 to S430) a battery system including N+1 batteries. Here, when at least one protection element is identified as being unable to withstand the short-circuit current (the short-circuit current exceeds the limit current), the battery system management device 400 may determine that the maximum number of batteries in the battery system is N.

[0098] In one embodiment, the battery system management device 400 may calculate the short circuit current applied to each protection element for each case where a short circuit occurs at multiple locations, and for all cases, the battery system management device 400 may determine the maximum number of batteries that allow all protection elements 210 to withstand the short circuit current.

[0099] For example, the battery system management device 400 may simulate a short circuit at each of P1 to P4 in a battery system including N batteries (S410 to S430). For all cases, when all protection elements are identified as being able to withstand the short circuit current (the short circuit current is less than or equal to the limit current), the battery system management device 400 may simulate four cases for a battery system including N+1 batteries (S410 to S430). Here, when at least one protection element is identified as being unable to withstand the short circuit current (the short circuit current exceeds the limit current), the battery system management device 400 may determine that the maximum number of batteries in the battery system is N.

[0100] Figure 6The present invention is a flowchart of a battery system management method according to another embodiment of the present invention.

[0101] The battery system management device 400 may define an equivalent model of the battery system 30 including N batteries ( S610 ).

[0102] Thereafter, when a short circuit occurs at a location in the battery system, the battery system management device 400 may calculate a short circuit current applied to the protection element using the equivalent model defined in S610 ( S620 ).

[0103] Here, for each case where a short circuit occurs at one or more locations, the battery system management device 400 can calculate the short circuit current applied to each protection element. For example, for each case where a short circuit occurs at P1 to P4, the battery system management device 400 can calculate the short circuit current applied to each protection element.

[0104] The battery system management device 400 may compare the short circuit current calculated in S620 with the limit current of the protection element (S630). Here, the battery system management device 400 may compare the short circuit current and the limit current of the protection element for all cases.

[0105] For all cases, when the short-circuit current of all protection elements is identified as being equal to or less than the limiting current (Y in S640), the battery system management device 400 can redefine the equivalent model (S610) by changing the number of batteries included in the battery system to N+1, and the redefined equivalent model can be used to calculate the short-circuit current (S620).

[0106] Here, when it is detected that the short-circuit current exceeds at least one protection element that limits the current (N in S640 ), the battery system management device 400 may determine the maximum number of batteries in the battery system as N ( S650 ).

[0107] Figure 7 is a circuit diagram for explaining an equivalent model of a battery according to an embodiment of the present disclosure.

[0108] The battery system management device 400 may define an equivalent model of the entire battery system based on a first equivalent model of the battery, a second equivalent model of the protection element, and a third equivalent model of the connection element 130, 230 electrically connecting the battery to an external device. Here, the battery system management device 400 may calculate a short-circuit current value using the equivalent model.

[0109] A first equivalent model of a battery may be defined as an equivalent circuit reflecting the characteristics of the battery.

[0110] For example, the first equivalent model may include an equivalent circuit of the battery and an equivalent circuit inside the battery. Here, the equivalent circuit of the battery may be defined as a circuit in which an open circuit voltage OCV, a first resistor Ri, and a second resistor Rd and a capacitor Cd connected in parallel are connected in series. In addition, the equivalent circuit inside the battery may be defined as an RL series circuit that effectively represents a short-circuit characteristic in a DC circuit, and may be defined as a circuit in which an internal resistor Ric and an internal inductor Lic are connected in series.

[0111] A second equivalent model of the protection element may be defined as a circuit including a resistor Rarc, a capacitor Carc, and a switch.

[0112] Meanwhile, in the battery system, the characteristics of voltage and current may change based on the occurrence of a short circuit. Therefore, with respect to the occurrence of a short circuit, a protection element (eg, a fuse) may change from a first state (melted) to a second state (cut off).

[0113] Here, the first state may be a state in which the conductor begins to melt due to heat generated inside the fuse before an arc occurs, and the second state may be a state in which the conductor melts and current flows into the air to cause an arc.

[0114] In order to realize the fusing characteristic of the protection element, the second equivalent model according to the embodiment of the present disclosure can be realized as a circuit including a resistor Rarc, a capacitor Carc and a switch, such as Figure 7 shown.

[0115] The third equivalent model of the connection element 130, 230 may be defined as an RL circuit in which a resistor Rec and an inductor Lec are connected in series. Here, the resistor Rec and the inductor Lec may be defined by resistance values ​​and inductances according to the length and characteristics of the connection element 130, 230 (eg, a cable or a bus bar).

[0116] Since the equivalent model according to the embodiment of the present disclosure is defined according to the connection structure of the battery system by reflecting the characteristics of the connecting elements 130, 230, the battery system management device 400 can calculate the short-circuit current by reflecting the differences in the time constants of the respective connecting elements 130, 230, which makes it possible to more accurately calculate the optimal number of batteries that can be applied to the battery system.

[0117] Figure 8 and Fig. 9 is an example of a battery system to which the present disclosure is applicable. Figure 8 The battery system shown may include a plurality of battery racks 100 as B-Links, and Fig. 9 The battery system shown may include a PCS 300 including a plurality of AC / DC inverters and a plurality of DC-Links.

[0118] exist Fig. 9 In the embodiment, each AC / DC inverter can be electrically connected to a DC-Link. Here, each DC-Link can include an E-Link and a plurality of B-Links. The Link can include at least one protection element (e.g., a fuse or a switching device) therein. The B-Link can be connected in parallel to the E-Link. Here, each B-Link can include a plurality of battery racks 100 connected in parallel.

[0119] exist Figure 8 In the E-Link, the B-Link may include a BCP 200 and a plurality of battery racks 100. Here, the battery racks 100 may be connected to the BCP 200 in parallel, and the BCP 200 may be electrically connected to the E-Link. Each battery rack 100 may include a BPU.

[0120] The BCP 200 and the BPU 110 may include at least one protection element (eg, a fuse and / or a switch device).

[0121] The battery system management device 400 can define Figure 8 and Fig. 9 An equivalent model of the battery system is shown, and the maximum number of battery racks 100 that can be included in the battery system can be determined using the defined equivalent model.

[0122] Here, the battery system management device 400 can calculate the short-circuit current applied to each protection element in each case where a short circuit occurs at multiple locations by reflecting the time constant characteristics of the connecting elements 130, 230 according to a predetermined connection structure, and for all cases, the battery system management device 400 can determine the maximum number of batteries that can withstand the short-circuit current.

[0123] exist Figure 8 and Fig. 9 In the battery system shown, Figure 5 In this case, a short-circuit current may be generated at one or more of a location inside the battery rack (P1), a location between the battery rack 100 and the BCP 200 (P2), a location between the BCP and the E-Link (P3), and a location between the E-Link and the PCS 300 (P4).

[0124] Fig.10 FIG. 1 is an operation flow chart of a battery system management method according to another embodiment of the present disclosure. Figures 11 to 15 is a block diagram for explaining the simulation results of the first to fifth cases. Figures 10 to 15 , describing the determination used Figure 8 and Fig. 9 The method of determining the optimum number of batteries for a battery system is shown.

[0125] refer to Fig.10 , the battery system management device 400 may sequentially perform simulations to calculate the short-circuit current in each case where a short circuit occurs at a plurality of locations, may sequentially identify simulation results, and may determine the maximum number of batteries to be included in the battery system. For example, the battery system management device 400 may sequentially perform simulations from the highest position to the lowest position in the structure of the battery system. For example, the simulation for calculating the short-circuit current may be performed in the order of P4, P3, P2, and P1.

[0126] refer to Fig.10 , the battery system management device 400 may perform simulation using an equivalent model of a battery system including N batteries ( S1010 ) to calculate a short-circuit current in a case where a short circuit occurs at P4 (a first case).

[0127] According to an embodiment, when a short circuit occurs at the highest position P4 in the structure of the battery system, as shown in FIG. Fig.11 As shown in FIG. 1 , a high short-circuit current applied from DC-Link #1 to #3 flows to the AC / DC converter connected to DC-Link #1. At this time, each protection element included in the battery needs to be able to withstand the generated short-circuit current. For example, Figure 5 As shown, each protection element located at A, B, and C must be able to withstand the high short-circuit current applied from DC-Link #1 to #3 at the corresponding location.

[0128] The battery system management device 400 may compare the short-circuit current of each protection element calculated as a simulation result with the limit current of each protection element.

[0129] As a result of the comparison, when the short-circuit current of all protection elements is identified as being equal to or less than the limit current (Y in S1020), the battery system management device 400 may change the number of battery racks 100 included in the battery system (e.g., increase the number by 1) to redefine the equivalent model, and may perform simulation using the redefined equivalent model. For example, in this case, the battery system management device 400 may determine that all protection elements are able to withstand the short-circuit current increased by the short circuit at each position, and may increase the number of battery racks 100 to redefine the equivalent model, and may perform simulation.

[0130] When it is detected that at least one protection element has a short circuit current exceeding the limit current (N in S1020), the battery system management device 400 may determine that the maximum number of battery racks 100 applicable to the battery system is N.

[0131] Next, the battery system management device 400 may perform a simulation of the next step to calculate a short-circuit current when a short circuit occurs in P3 (second case) ( S1030 ).

[0132] When a short circuit occurs at P3, Fig.12 As shown, a high short-circuit current applied from DC-Link #2 and #3 and B-Link of DC-Link #1 flows to E-Link of DC-Link #1. At this time, each protection element included in the battery needs to be able to withstand the generated short-circuit current.

[0133] The battery system management device 400 may compare the short-circuit current of each protection element calculated as a simulation result with the limit current of each protection element.

[0134] When at least one protection element having a short-circuit current exceeding the limiting current is detected (N in S1040), the battery system management device 400 can determine that the at least one protection element cannot withstand the generated short-circuit current, can change the number of battery racks 100 included in the battery system (for example, reduce the number by 1) to redefine the equivalent model, and can perform simulation using the redefined equivalent model.

[0135] Meanwhile, when the short circuit currents of all protection elements are identified as being equal to or less than the limit current (Y in S1040 ), the battery system management device 400 may perform simulation to calculate the short circuit current when a short circuit occurs at P2 (third case) ( S1050 ).

[0136] When a short circuit occurs at P2, Fig.13 As shown, a high short-circuit current applied from the battery rack 100 of B-Link #2 of DC-Link #1 flows to the BCP of B-Link #2. At this time, each protection element included in the battery system must be able to withstand the short-circuit current generated at each position.

[0137] The battery system management device 400 may compare the short-circuit current of each protection element calculated as a simulation result with the limit current of each protection element.

[0138] When at least one protection element having a short-circuit current exceeding the limiting current is detected (N in S1060), the battery system management device 400 can determine that the at least one protection element cannot withstand the generated short-circuit current, can change the number of battery racks 100 included in the battery system (for example, reduce the number by 1) to redefine the equivalent model, and can perform simulation using the redefined equivalent model.

[0139] When the short-circuit currents of all protection elements are identified as being equal to or less than the limit current (Y in S1060 ), in the next step, the battery system management device 400 may perform a simulation to calculate the short-circuit current when a short circuit occurs at P1 (a fourth case) ( S1070 ).

[0140] When a short circuit is generated at P1, as Fig.14 As shown, the high short circuit applied from other battery racks 100 of DC-Link #2 and #3 and B-Link #2 of DC-Link #1 flows to the BPU 110 of the battery rack generating the short circuit current. At this time, each protection element included in the battery system must be able to withstand the short circuit current generated at each location.

[0141] The battery system management device 400 may compare the short-circuit current of each protection element calculated as a simulation result with the limit current of each protection element.

[0142] When at least one protection element with a short-circuit current exceeding the limiting current is detected (N in S1080), the battery system management device 400 can redefine the equivalent model by changing the number of battery racks 100 included in the battery system (for example, reducing the number by 1), and simulation can be performed using the redefined equivalent model.

[0143] When the short-circuit currents of all protection elements are identified as being equal to or less than the limit current (Y in S1080 ), the battery system management device 400 may ultimately determine the number of batteries applied to the current equivalent model as the optimal number of batteries in the battery system ( S1090 ).

[0144] Meanwhile, the battery system management device 400 may also simulate a situation where a short circuit occurs at a plurality of locations simultaneously or at specific time intervals, and may calculate an optimal number of batteries based on the simulation result.

[0145] For example, Fig.15 As shown, the battery system management device 400 may additionally perform simulation to calculate the short-circuit current in a case where a short circuit occurs simultaneously at P3 and P3 ′ (eg, the fifth case).

[0146] When a short circuit occurs at P3 and P3' at the same time, a high short circuit current flows to the E-Link of DC-Link#1 and the E-Link of DC-Link#3. At this time, each protection element included in the battery system must be able to withstand the short circuit current generated at each position. The battery system management device 400 can simulate the fifth situation in a similar manner to the above, can identify whether the short circuit current of all protection elements is equal to or less than the limit current, and can adjust the number of batteries.

[0147] Fig.16 It is a block diagram for explaining the structure of the battery system derived according to the present disclosure.

[0148] Fig.16 (A) shows a battery system having an asymmetric parallel connection structure, and Fig.16 (B) shows a battery system with a symmetrical parallel connection structure.

[0149] about Fig.16 (A) and Fig.16 (B), as a result of calculating the maximum number of battery racks 100 using the present disclosure, it is recognized that the asymmetric parallel connection structure (A) can include more battery racks 100 than the symmetric parallel connection structure (B).

[0150] Due to the connection structure of the battery system, the length of the connection elements 130, 230 including the symmetrical parallel connection structure (A) is shorter than that of the asymmetrical parallel connection structure (B), and therefore has relatively low inductance and resistance. Therefore, the symmetrical parallel connection structure (A) has a relatively small time constant and thus has a relatively high total short-circuit current. In contrast, the asymmetrical parallel connection structure (B) has a relatively low total short-circuit current and can include more battery racks 100 than the symmetrical parallel connection structure (B).

[0151] Fig.17 is a block diagram of a battery system management device 400 according to an embodiment of the present disclosure.

[0152] The battery system management device 400 may include at least one processor 410, a memory 420 storing at least one command to be executed by the processor, and a transceiver 430 connected to a network for communication. In addition, the battery system management device 400 may further include, for example, an input interface device 440, an output interface device 450, and a separate storage device 460. In addition, the various components included in the battery system management device 400 may be connected to each other through a bus 470 and may communicate with each other.

[0153] The processor 410 may refer to a central processing unit (CPU), a graphics processing unit (GPU). A dedicated processor on which the method according to the embodiment of the present disclosure is executed. The memory (or storage device) may include at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory may include at least one of a read-only memory (ROM) and a random access memory (RAM).

[0154] At the same time, at least one command executed by the processor may include: a command to define an equivalent model of a battery system having a predefined connection structure including multiple batteries and at least one protection element; a command to calculate the short-circuit current generated in the battery system when a short circuit is generated at a certain location in the battery system by using the equivalent model and reflecting the time constant characteristics of the connection element according to the predefined connection structure; a command to compare the calculated short-circuit current with the limiting current of the protection element; and a command to determine the number of batteries to be set in the battery system based on the comparison result.

[0155] The protection element may be placed at one or more of the input / output terminals of the battery, the connection points of the battery, and the connection points of the battery pack.

[0156] The command to define an equivalent model may include a command to define an equivalent model of the battery system based on: a first equivalent model of the battery; a second equivalent model of the protection element; and a third equivalent model of a connection element electrically connecting the battery to an external device. Here, the third equivalent model may be defined as an RL equivalent circuit having a resistance value and an inductance corresponding to the length of the connection element.

[0157] The command to calculate the short circuit current may include a command to calculate the short circuit current applied to each of the plurality of protection elements by reflecting a time constant characteristic of the connection element according to a predefined connection structure when a short circuit occurs at one or more locations.

[0158] The location where the short circuit occurs may include at least one of a first location, a second location, a third location and a fourth location, the first location being defined as a location inside the battery, the second location being defined as a location between the connection points between the batteries, the third location being defined as a location between the connection points of the batteries and the connection points of the battery pack, and the fourth location being defined as a location between the connection points of the battery pack and the power conversion system.

[0159] The command to compare the calculated short-circuit current with the limit current of the protection element may include a command to identify whether the short-circuit current exceeds the limit current defined based on the short-circuit capacity of each of the plurality of protection elements.

[0160] The command to determine the number of batteries may include a command to determine a maximum number of batteries that prevents a short-circuit current applied to each of the plurality of protection elements from exceeding a limiting current of each of the plurality of protection elements.

[0161] The command to calculate the short-circuit current may include, for each case where a short circuit occurs at a plurality of locations, a command to calculate the short-circuit current applied to each of the plurality of protection elements by reflecting the time constant characteristics of the connection elements according to a predefined connection structure. Here, the command to determine the number of batteries may include, for all cases, a command to determine the maximum number of batteries that prevents the short-circuit current applied to each of the plurality of protection elements from exceeding a limit current of each of the plurality of protection elements.

[0162] The command to determine the maximum number of batteries may include: a command to redefine the equivalent model by changing the number of batteries included in the battery system according to a comparison result of the short circuit current and the limit current; and a command to recalculate the short circuit current based on the redefined equivalent model.

[0163] Meanwhile, the operation of the method according to the embodiment of the present disclosure can be implemented as a computer-readable program or code on a computer-readable recording medium. The computer-readable re-encoded medium includes all types of recording devices storing data readable by a computer system. In addition, the computer-readable re-encoded medium can be distributed on a computer system connected to a network so that the computer-readable program or code can be stored and executed in a distributed manner.

[0164] Although some aspects of the present disclosure have been described in the context of an apparatus, these aspects also represent the description of the corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, the aspects described in the context of the method also represent the description of the feature of the corresponding block or project or corresponding device. Some or all of the method steps can be performed by (or using) for example a hardware device (such as a microprocessor, a programmable computer or an electronic circuit). In some embodiments, one or more of the most important method steps can be performed by such a device.

[0165] While the present disclosure has been described with reference to the embodiments thereof, it will be appreciated by those skilled in the art that various modifications and variations may be made thereto without departing from the spirit and scope of the present disclosure as set forth in the following claims.

Claims

1. A battery system management device, the battery system management device comprising: at least one processor capable of communicating with the battery system; as well as a memory coupled to the at least one processor and configured to store at least one command to be executed by the at least one processor, The at least one command includes: A command for defining an equivalent model of the battery system, the battery system being configured to have a predefined connection structure including a plurality of batteries and at least one protection element; a command for calculating, when a short circuit occurs at a certain position in the battery system, a short circuit current generated in the battery system by using the equivalent model and reflecting a time constant characteristic of a connection element according to the predefined connection structure; a command for comparing the calculated short-circuit current with a limiting current of the protection element; and A command for determining the number of batteries provided in the battery system based on the comparison result.

2. The battery system management device according to claim 1, wherein: The protection element is provided at one or more of an input / output terminal of the battery, a connection point of the battery, and a connection point of the battery pack.

3. The battery system management device according to claim 1, wherein: The command for defining the equivalent model includes a command for defining the equivalent model of the battery system based on: a first equivalent model of the battery; A second equivalent model of the protection element; and A third equivalent model of a connection element that electrically connects the battery to an external device.

4. The battery system management device according to claim 3, wherein: The third equivalent model is defined as an RL equivalent circuit having a resistance value and an inductance corresponding to the length of the connection element.

5. The battery system management device according to claim 1, in, The commands for calculating the short-circuit current include: A command for calculating a short circuit current applied to each of a plurality of protection elements by reflecting a time constant characteristic of the connection element according to the predefined connection structure when the short circuit occurs at one or more locations.

6. The battery system management device according to claim 5, wherein: The locations where the short circuit occurs include: a first position, the first position being defined as a position inside the battery; a second position, the second position being defined as a position between battery-to-battery connection points; a third position, the third position being defined as a position between a connection point of the battery and a connection point of the battery pack; and A fourth position is defined as a position between a connection point of the battery pack and the power conversion system.

7. The battery system management device according to claim 5, wherein: The commands used for comparison are: A command for identifying, for each of the plurality of protection elements, whether the short-circuit current exceeds a limit current defined based on a short-circuit capacity of the protection element.

8. The battery system management device according to claim 1, in, The command for determining the number of batteries includes: A command for determining a maximum number of batteries that prevents a short circuit current applied to each of a plurality of protection elements from exceeding the limit current of each of the plurality of protection elements.

9. The battery system management device according to claim 8, wherein: The commands for calculating the short-circuit current include: a command for calculating the short-circuit current applied to each of the plurality of protection elements by reflecting the time constant characteristic of the connection element according to the predefined connection structure for each case where a short circuit occurs at a plurality of locations, and The command for determining the number of batteries includes: A command for determining the maximum number of batteries that prevents the short-circuit current applied to each of the plurality of protection elements from exceeding the limit current of each of the plurality of protection elements for all of the situations.

10. The battery system management device according to claim 9, wherein: The command for determining the maximum number of batteries includes: a command for redefining an equivalent model by changing the number of batteries included in the battery system according to a comparison result of the short-circuit current and the limit current; and Command to recalculate the short-circuit current based on the redefined equivalent model.

11. A method for managing a battery system by means of a battery system management device, the method comprising the following steps: defining an equivalent model of a battery system, the battery system being configured to have a predefined connection structure including a plurality of batteries and at least one protection element; When a short circuit occurs at a certain location in the battery system, using the equivalent model to calculate a short circuit current generated in the battery system by reflecting a time constant characteristic of a connection element according to the predefined connection structure; comparing the calculated short-circuit current with a limiting current of the protection element; as well as The number of batteries provided in the battery system is determined based on the comparison result.

12. The method according to claim 11, wherein: The at least one protection element is disposed at one or more of an input / output terminal of the battery, a connection point of the battery, and a connection point of the battery pack.

13. The method according to claim 11, wherein: The step of defining the equivalent model comprises defining the equivalent model of the battery system based on: a first equivalent model of the battery; A second equivalent model of the protection element; and A third equivalent model of a connection element that electrically connects the battery to an external device.

14. The method according to claim 13, wherein: The third equivalent model is defined as an RL equivalent circuit having a resistance value and an inductance corresponding to the length of the connection element.

15. The method according to claim 11, in, The step of calculating the short-circuit current comprises: When the short circuit occurs at one or more locations, a short circuit current applied to each of the plurality of protection elements is calculated by reflecting a time constant characteristic of the connection element according to the predefined connection structure.

16. The method according to claim 15, wherein: The location where the short circuit occurs includes at least one of the following locations: a first position, the first position being defined as a position inside the battery; a second position, the second position being defined as a position between battery-to-battery connection points; a third position, the third position being defined as a position between a connection point of the battery and a connection point of the battery pack; and A fourth position is defined as a position between a connection point of the battery pack and the power conversion system.

17. The method according to claim 15, wherein: The steps for comparison include: For each of the plurality of protection elements, it is identified whether the short-circuit current exceeds a limit current defined based on a short-circuit capacity of the protection element.

18. The method according to claim 11, in, The step of determining the number of batteries comprises: A maximum number of batteries that prevents a short circuit current applied to each of a plurality of protection elements from exceeding the limit current of each of the plurality of protection elements is determined.

19. The method according to claim 18, in, The step of calculating the short-circuit current comprises: for each case where a short circuit occurs at a plurality of locations, calculating the short circuit current applied to each of the plurality of protection elements by reflecting the time constant characteristic of the connection element according to the predefined connection structure, and The step of determining the number of batteries includes: For all of the cases, a maximum number of batteries that prevents the short-circuit current applied to each of the plurality of protection elements from exceeding the limit current of each of the plurality of protection elements is determined.

20. The method according to claim 19, wherein: The step of determining the maximum number of batteries comprises: redefining an equivalent model by changing the number of batteries included in the battery system according to a comparison result of the short-circuit current and the limit current; and The short-circuit current is recalculated based on the redefined equivalent model.

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