Battery fire detection method using cloud services

Abstract

This invention provides a cloud-based fire detection method for ESS (Electrical System) that can detect the presence or absence of a fire in the ESS or battery pack at an early stage, even when no fire detection sensors are installed on-site. [Solution] A fire detection method for an ESS according to one embodiment of the present invention, which solves the above technical problems, comprises a first step of receiving battery status data from a battery management system via a cloud server, and a second step of analyzing the received battery status data to determine whether or not a fire has occurred. According to the present invention, it is possible to detect whether or not a fire has occurred in an ESS without providing the ESS with a separate fire detection sensor.

Description

[Technical Field]

[0001] This invention relates to a method for detecting battery fires using cloud services. [Background technology]

[0002] An ESS (Energy Storage System) is a system that can store surplus electricity or electricity produced using new renewable energy sources. By utilizing an ESS, idle electricity can be stored during periods of low electricity demand, and electricity can be supplied during periods of high demand, thereby smoothly controlling the supply and demand of electricity.

[0003] While fires can occur in ESS (Emergency Storage Systems) during operation, if an ESS fire is not extinguished early, it becomes difficult to control. Therefore, it is necessary to detect the presence or absence of an ESS fire at an early stage.

[0004] While the presence or absence of a fire in an ESS (Emergency Storage System) can be detected using additional sensors such as smoke detection sensors, it becomes difficult for these sensors to detect a fire if the battery is discharged or malfunctions. In particular, ESSs are often operated unmanned in remote areas, making it difficult to confirm the presence or absence of a fire in its early stages.

[0005] The information disclosed above in the background art of such inventions is merely for the purpose of improving the understanding of the background of the present invention, and therefore may include information that does not constitute prior art. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a method for detecting the presence or absence of a fire in an ESS or battery pack at an early stage. Furthermore, the present invention aims to provide a method for detecting the occurrence of a fire at an early stage even when a fire detection sensor is not installed at the site. [Means for solving the problem]

[0007] To solve the above technical problems, an embodiment of the present invention provides a fire detection method for an ESS (Energy Storage System), comprising: a first step of receiving battery status data from a battery management system via a server; and a second step of analyzing the received battery status data to determine whether or not a fire has occurred.

[0008] In one embodiment, the second step can determine that a fire has occurred if a cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the rack is lower than the threshold voltage.

[0009] In one embodiment, the second step can determine that a fire has occurred if all three conditions are met: a cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the rack is lower than the threshold voltage; an alarm is issued indicating that the temperature inside the module is maintained above a certain value; a protective operation is performed because the temperature inside the module is maintained above a certain value; an alarm is issued indicating a communication error between the rack BMS and the module BMS; a protective operation is performed because a communication error occurs between the rack BMS and the module BMS; and the PCB temperature of the module BMS is maintained above a certain value.

[0010] In one embodiment, the second step can determine that a fire has occurred if at least two of the following three conditions are met: a cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the rack is lower than the threshold voltage.

[0011] In one embodiment, the second step can determine that a fire has occurred if at least two of the following three conditions are met: a cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the rack is lower than the threshold voltage; an alarm is issued indicating that the temperature inside the module is maintained above a certain value; a protective operation is performed because the temperature inside the module is maintained above a certain value; an alarm is issued indicating a communication error has occurred between the rack BMS and the module BMS; a protective operation is performed because a communication error has occurred between the rack BMS and the module BMS; and the PCB temperature of the module BMS is maintained above a certain value.

[0012] In one embodiment, the second step can determine that a fire has occurred if the lowest cell voltage in the rack is lower than the threshold voltage, the current measured in the rack is lower than the threshold current, the maximum module temperature in the rack is higher than the threshold temperature, and the lowest cell voltage in the rack is lower than the threshold voltage and the maximum module temperature in the rack is higher than the threshold temperature occur in the same module.

[0013] A fire detection method for an ESS according to one embodiment of the present invention may further include a third step of notifying that a fire event has occurred when it is determined that a fire has occurred.

[0014] In one embodiment, the server is a cloud server.

[0015] A battery pack fire detection method according to one embodiment of the present invention comprises a first step of receiving battery status data from a battery management system via a server, and a second step of analyzing the received battery status data to determine whether or not a fire has occurred.

[0016] In one embodiment, in the second step, when the cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the battery pack is lower than the threshold voltage, it can be determined that a fire has occurred.

[0017] In one embodiment, in the second step, when all of the three conditions that the cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the battery pack is lower than the threshold voltage are satisfied, and an alarm that the temperature in the module is maintained at a certain value or higher occurs, or the temperature in the module is maintained at a certain value or higher and a protection operation is performed, or an alarm that a communication error has occurred between the battery pack BMS and the module BMS occurs, or a communication error has occurred between the battery pack BMS and the module BMS and a protection operation is performed, or the PCB temperature of the module BMS is maintained at a certain value or higher, when at least one of the five conditions occurs, it can be determined that a fire has occurred.

[0018] In one embodiment, in the second step, when at least two of the three conditions that the cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the battery pack is lower than the threshold voltage are satisfied, it can be determined that a fire has occurred.

[0019] In one embodiment, the second step satisfies at least two of the following three conditions: a cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the battery pack is lower than the threshold voltage. When an alarm indicating that the temperature within the module is maintained at a certain value or higher and a protection operation is performed, an alarm indicating that a communication error has occurred between the battery pack BMS and the module BMS, or a protection operation is performed due to a communication error between the battery pack BMS and the module BMS, or the PCB temperature of the module BMS is maintained at a certain value or higher occurs, it can be determined that a fire has occurred.

[0020] In one embodiment, the second step can determine that a fire has occurred when the lowest cell voltage in the battery pack is lower than the threshold voltage, the current measured in the battery pack is lower than the threshold current, the maximum module temperature in the battery pack is higher than the threshold temperature, and both the lowest cell voltage in the battery pack being lower than the threshold voltage and the maximum module temperature in the battery pack being higher than the threshold temperature occur in the same module.

[0021] The method for detecting a fire in a battery pack according to an embodiment of the present invention may further include a third step of notifying that a fire event has occurred when it is determined that a fire has occurred.

[0022] In one embodiment, the server is a cloud server.

Advantages of the Invention

[0023] According to the present invention, it is possible to detect whether or not a fire has occurred in an ESS or battery pack without having to install a separate fire detection sensor on the ESS or battery pack. In the case of a cloud system, since the data is received in a very short time, it is possible to recognize the fire in its early stages and take appropriate action. Furthermore, by appropriately setting the conditions for determining the occurrence of a fire in the cloud data according to the type of battery and the installation environment, it is possible to respond to a variety of environments and needs.

[0024] However, the effects that can be obtained by the present invention are not limited to those described above, and other technical effects not mentioned will be clearly understood by those skilled in the art from the description of the invention below. [Brief explanation of the drawing]

[0025] The following drawings attached to this specification illustrate embodiments of the present invention and, together with the detailed description of the invention later, serve to further illustrate the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited only to what is shown in the drawings. [Figure 1] This is a schematic diagram showing a secondary battery electrode assembly. [Figure 2] This diagram schematically shows the configuration of a pouch-type rechargeable battery. [Figure 3] This diagram shows the general external configuration of a prismatic rechargeable battery. [Figure 4] This is a cross-sectional view of a cylindrical rechargeable battery. [Figure 5] This is a conceptual diagram illustrating a fire detection method for an ESS (Emergency System) that utilizes the cloud service of the present invention. [Figure 6] This flowchart shows the procedure for determining whether or not a fire event has occurred according to one embodiment of the present invention. [Figure 7] This is a flowchart of a fire event occurrence determination algorithm according to one embodiment of the present invention. [Figure 8] This flowchart shows a fire event occurrence determination algorithm according to another embodiment of the present invention. [Figure 9] This flowchart shows the procedure for determining whether or not a fire event has occurred according to another embodiment of the present invention. [Figure 10] This is a block diagram showing a computer system for implementing the method according to an embodiment of the present invention. [Figure 11] This is an illustrative diagram of a secondary battery module in which secondary batteries manufactured according to the present invention are arranged. [Figure 12] Figure 11 is an example diagram of a secondary battery pack that includes the secondary battery module shown. [Figure 13] Figure 12 is a conceptual diagram of an automobile including a secondary battery pack. [Modes for carrying out the invention]

[0026] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used herein and in the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but in accordance with the principle that inventors may appropriately define the concepts of terms in order to best describe their invention, they should be interpreted in a manner and concept consistent with the technical idea of ​​the present invention. Accordingly, the embodiments described herein and the configurations shown in the drawings represent only some of the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and it should be understood that there may be a variety of equivalents and variations that can be substituted for them at the time of filing. Also, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the shapes, figures, stages, actions, members, elements, and / or groups thereof mentioned, and do not exclude the presence or addition of one or more other shapes, figures, actions, members, elements, and / or groups thereof.

[0027] Furthermore, for the sake of understanding the invention, the attached drawings are not shown to actual scale, and the dimensions of some components may be exaggerated. Also, identical components may be assigned the same reference numeral in different embodiments.

[0028] When two comparisons are described as "identical," it means they are "substantially identical." Therefore, substantial identity may include deviations considered low in this field, such as deviations of 5% or less. Furthermore, when a parameter is described as uniform in a given domain, it can mean uniform from an average perspective. While terms like "first," "second," etc., are used to describe a variety of components, it goes without saying that these components are not limited by these terms. These terms are simply used to distinguish one component from another, and unless otherwise stated, the first component may be the second component.

[0029] Throughout the specification, unless otherwise stated, each component may be singular or plural.

[0030] The placement of any configuration "above (or below)" a component or "above (or below)" a component can mean not only that the configuration is placed in contact with the upper (or lower) surface of the component, but also that other configurations may be interposed between the component and any configuration placed above (or below) it.

[0031] Furthermore, when a component is described as being "on," "connected to," or "coupled to" another component, it should be understood that while the components may be directly connected to or linked to each other, other components may be "interposed" between them, or each component may be "connected," "coupled," or "linked" through other components.

[0032] As used herein, the terms "and / or" include any and all combinations of one or more of the items listed relating to the invention. Furthermore, when describing embodiments of the invention, the use of "may also apply" applies to "one or more embodiments of the invention." Expressions such as "one or more" preceding an element list modify the entire element list, not individual elements of the list.

[0033] Throughout the specification, "A and / or B" means A, B, or A and B unless otherwise specified, and "C to D" means C or greater and D or less unless otherwise specified.

[0034] When syntax such as “at least one of A, B, and C,” “at least one of A, B, or C,” “at least one selected from the group A, B, and C,” or “at least one selected from among A, B, and C” is used to specify a list of elements A, B, and C, the syntax can refer to any suitable combination. The term “use” is considered synonymous with the term “utilize.” Terms such as “substantially,” “about,” and similar terms as used herein are used as approximations, not terms of degree, to account for the intrinsic variability of measured or calculated values ​​as perceived by the general art in the art.

[0035] In this specification, terms such as first, second, third, etc., are used to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, drawing layer, or section from other elements, components, regions, drawing layers, or sections. Accordingly, the first elements, components, regions, layers, or sections discussed below may be named second elements, components, regions, layers, or sections, to the extent that they do not deviate from the teachings of the exemplary embodiments.

[0036] As illustrated, in describing the relationship between one element or feature and another, spatially relative terms such as “beneath,” “below,” “lower,” “above,” and “upper” are used in the specification for ease of explanation. Spatially relative positions will be understood to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figure. For example, if the device in the drawing is turned upside down, the other elements will be understood as “below” or “below,” and the described element as “above” or “upper” of the other elements. Thus, the term “below” can encompass both up and down directions.

[0037] The terms used herein are for describing embodiments of the present invention and are not intended to limit the invention.

[0038] The battery pack includes at least one battery module and a pack housing having a housing space for accommodating at least one of the battery modules.

[0039] The battery module may comprise a plurality of battery cells and a module housing. The battery cells can be housed inside the module housing in a stacked configuration. The battery cells may be provided with positive and negative leads. Depending on the battery configuration, circular, rectangular, or pouch-type battery cells can be used.

[0040] The battery pack may consist of a single cell stack instead of the battery module, with each cell stack constituting a single module. The cell stack may be housed in a housing space within the pack housing, or in a housing space partitioned by a frame, bulkheads, or the like.

[0041] The aforementioned battery cells generate a large amount of heat during charging and discharging. This generated heat accumulates in the battery cells, accelerating their degradation. Therefore, the battery pack further includes cooling elements to suppress the degradation of the battery cells. The cooling elements are provided at the bottom of the housing space where the battery cells are located, but are not limited to this location; they may also be provided at the top or sides, depending on the battery pack.

[0042] Each of the battery cells is capable of discharging exhaust gas generated inside the battery cell under abnormal operating conditions, also known as thermal runaway or thermal events, to the outside of the battery cell. The battery pack or battery module may be equipped with exhaust ports or the like for discharging the exhaust gas to prevent damage to the battery pack or module.

[0043] A battery pack may include a battery and a battery management system (BMS) for managing the battery. The battery management system may include a detection device, a balancing device, and a control device. A battery module may include multiple cells connected in series or parallel to each other. Battery modules can be connected in series or parallel to each other.

[0044] The detection device can detect the state of the battery (voltage, current, temperature, etc.) and detect state information indicating the state of the battery. The detection device can detect the voltage of each cell or each battery module that makes up the battery. The detection device may also detect the current flowing through each battery module that makes up the battery module or battery pack. The detection device may also detect the temperature of the cells and / or modules and / or ambient temperature at at least one point in the battery.

[0045] A balancing device can perform balancing operations on battery modules and / or cells that constitute a battery. A control device can receive state information (voltage, current, temperature, etc.) of the battery modules from a detection device. Based on the state information received from the detection device, the control device can monitor and calculate the state of the battery modules (voltage, current, temperature, charge state (SOC), state of health (SOH), etc.). The control device may also perform control functions (e.g., temperature control, balancing control, charge / discharge control, etc.) and protection functions (e.g., over-discharge, over-charge, overcurrent prevention, short-circuit, shut-off function, etc.) based on the state monitoring results. The control device may also perform wired or wireless communication functions with external devices of the battery pack (e.g., a higher-level controller, or a vehicle or charger, or a PCS, etc.).

[0046] The control device may control the battery's charging and discharging operations and protection operations. For this purpose, the control device may include a charging / discharging control unit, a balancing control unit, and a protection unit.

[0047] The aforementioned battery management system is a system that monitors the battery status and performs diagnostic and control, communication, and protection functions, and may calculate the charge / discharge status, calculate the battery life or state of health (SOH), cut off battery power (relay control) when necessary, perform thermal management (cooling, heating, etc.) control, perform high-voltage interlock functions, and detect and calculate insulation and short-circuit conditions.

[0048] A relay may be a mechanical conductor that is switched on and off by the magnetic force of a coil, or it may be a semiconductor switch such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

[0049] The relay control may consist of one or more relays and a pre-charge relay at the positive and negative terminals, respectively, to interrupt the power supply from the battery in the event of a problem with the vehicle and battery system.

[0050] The aforementioned pre-charge control may include a function to prevent inrush current from being drawn into the high-voltage capacitor on the inverter input side when a battery load is connected. This function involves activating the pre-charge relay before connecting the main relay when the vehicle starts up, and connecting it to the pre-charge resistor.

[0051] Figure 1 schematically shows the electrode assembly that is embedded in the casing of a secondary battery.

[0052] The electrode assembly 10 may be formed by winding or stacking a laminate of a first electrode plate 11, a separator 12, and a second electrode plate 13, which are formed in a plate or film shape. In the case of a wound laminate, the winding axis of the electrode assembly 10 may be parallel to the longitudinal direction of a case (not shown). The electrode assembly 10 may also be a stack type rather than a wound type, but the present invention does not limit the shape of the electrode assembly 10. Furthermore, the electrode assembly 10 may be a Z-stack electrode assembly in which the first electrode plate and the second electrode plate are inserted on both sides of a Z-shaped bent separator. Also, one or more electrode assemblies 10 can be stacked so that their long sides are adjacent to each other and housed inside the case, but the present invention does not limit the number of electrode assemblies. The first electrode plate 11 of the electrode assembly 10 can play the role of a negative electrode, and the second electrode plate 13 can play the role of a positive electrode, and vice versa.

[0053] The first electrode plate 11 is formed by coating a first electrode active material such as graphite or carbon onto a first substrate made of a metal foil such as copper, a copper alloy, nickel, or a nickel alloy, and may include a first electrode tab (or first untouched area) 14 which is an area where the first electrode active material is not coated. The first electrode tab 14 can be connected to an external first terminal (not shown). In some examples, the first electrode tab 14 can be formed by cutting it in advance to protrude to one side when manufacturing the first electrode plate 11, and can protrude further to one side from the separator 12 without further cutting.

[0054] The second electrode plate 13 is formed by coating a second electrode active material, such as a transition metal oxide, onto a substrate made of a metal foil, such as aluminum or an aluminum alloy, and may include a second electrode tab (or second uncovered area) 15, which is an area where the second electrode active material is not coated. The second electrode tab 15 can be connected to an external second terminal (not shown). In some examples, the second electrode tab 15 can be formed by cutting it in advance to protrude to the other side when manufacturing the second electrode plate 13, and can protrude further to the other side from the separator 12 without further cutting.

[0055] In some embodiments, the first electrode tab 14 may be located on the right side of the electrode assembly 10, and the second electrode tab 15 may be located on the left side of the electrode assembly 10, or on one side in the same direction. In some embodiments, the first electrode tab 14 and the second electrode tab 15 may be located on the top of the electrode assembly 10.

[0056] Here, the left, right, and top are for illustrative purposes only, based on the electrode assembly 10 shown in Figure 1, and their positions can be changed when the secondary battery rotates left / right or up / down.

[0057] The separator 12 functions to prevent a short circuit between the first electrode plate 11 and the second electrode plate 13 while allowing the movement of lithium ions. The separator 12 may be made of, for example, a polyethylene film, a polypropylene film, or a polyethylene-polypropylene film.

[0058] In some embodiments, the electrode assembly 10 may be housed in an outer casing (not shown) and filled with electrolyte. In the case of a pouch-type secondary battery, the electrode assembly 10 can be housed in a pouch made of a flexible material in the form shown in Figure 1, and in the case of a prismatic secondary battery, the electrode assembly 10 can be housed in a prismatic metal case in the form shown in Figure 1.

[0059] Figure 2 shows a schematic representation of a pouch-type rechargeable battery.

[0060] A pouch-type secondary battery consists of an electrode assembly 10 and a pouch 20 that houses the electrode assembly 10.

[0061] The electrode assembly 10 is as shown in Figure 1, and the first electrode tab 14 and the second electrode tab 15 of the electrode assembly 10 can be electrically connected by welding to the external first terminal lead 16 and second terminal lead 17, respectively. Tab films 18 can be attached to the first terminal lead 16 and the second terminal lead 17 for insulation from the pouch 20.

[0062] The pouch 20 can be sealed by the sealing portions 21 at its periphery contacting each other while the electrode assembly 10 is housed inside. However, sealing may be performed with a tab film 18 interposed between the sealing portions 21. The sealing portions 21 of the pouch 20 are made of a heat-sealable material, but since heat-sealable materials generally have weak adhesion to metals, they can be fused to the pouch 20 with a thin, film-like tab film 18 interposed between them.

[0063] The appearance of the rectangular secondary battery shown in Figure 3 is described below.

[0064] The rectangular case 71 forms the overall appearance of the rectangular secondary battery and is made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. The case 51 can also provide space for housing the electrode assembly.

[0065] The cap assembly 60 may include a cap plate 61 that covers the opening of the case 71, and both the case 51 and the cap plate 61 are made of a conductive material. Here, the first terminal 63 and the second terminal 62 may be electrically connected to the first electrode tab 14 and the second electrode tab 15 of the internal electrode assembly 10 and may be provided so as to protrude outward through the cap plate 61.

[0066] The cap plate 61 has an electrolyte inlet 64 with a sealing plug and a vent 66 with a notch 65. The vent 66 is for degassing gas generated from inside the battery.

[0067] Figure 4 is a cross-sectional view of a cylindrical secondary battery.

[0068] The cylindrical secondary battery includes an electrode assembly 30, a case that houses the electrode assembly 30 and an electrolyte, a cap assembly 50 that is coupled to the opening of the case and seals the case, and an insulating plate 37 located inside the case between the electrode assembly 30 and the cap assembly 50.

[0069] The electrode assembly 30 may include a separator 32 and a first electrode 33 and a second electrode 31 positioned on either side of the separator 32, and is wound into a jelly-roll shape.

[0070] The first electrode 33 includes a first substrate and a first active material layer located on the first substrate. A first lead tab 35 can extend outward from a first blank portion of the first substrate where the first active material layer is not located, and the first lead tab 35 can be electrically connected to the cap assembly 50.

[0071] The second electrode 31 includes a second substrate and a second active material layer located on the second substrate. A second lead tab 34 can extend outward from a second blank portion of the second substrate where the second active material layer is not located, and the second lead tab 34 can be electrically connected to the case 10. The first lead tab 35 and the second lead tab 34 can extend in opposite directions to each other.

[0072] The first electrode 33 can function as a positive electrode. In this case, the first substrate is, for example, aluminum foil, and the first active material layer may include, for example, a transition metal oxide. The second electrode 31 can function as a negative electrode. In this case, the second substrate is, for example, copper foil or nickel foil, and the second active material layer may include, for example, graphite.

[0073] The separator 32 functions to prevent short circuits between the first electrode 33 and the second electrode 31 while allowing the movement of lithium ions. The separator 32 is made of, for example, a polyethylene film, a polypropylene film, or a polyethylene-polypropylene film.

[0074] The case houses the electrode assembly 30 and the electrolyte, and together with the cap assembly 50, forms the outer shape of the battery. The case may include a substantially cylindrical body portion 42 and a bottom portion 41 connected to one side of the body portion 42. The body portion 42 may have a beading portion 43 that is deformed inward, and the open end of the body portion 42 may have a crimping portion 45 that is bent inward.

[0075] The beading portion 43 can prevent the electrode assembly 30 from moving inside the case and facilitate the placement of the gasket 44 and the cap assembly 50. The crimping portion 45 can firmly fix the cap assembly 50 by applying pressure to the periphery of the cap assembly 50 via the gasket 44. The case is made of, for example, nickel-plated iron.

[0076] The cap assembly 50 can be secured inside the crimping portion 45 via the gasket 44 to seal the case. The cap assembly 50 may include, but is not limited to, a cap-up, safety vent, cap-down, insulating member, and subplate, and is highly deformable.

[0077] The cap-up may be located at the uppermost side of the cap assembly 50. The cap-up may include a terminal section that bulges upward and protrudes for connection to an external circuit, and an outlet for discharging gas may be located around the terminal section.

[0078] The safety vent may be located below the cap-up. The safety vent may include a projection that bulges downward and protrudes and connects to a subplate, and at least one notch located around the projection.

[0079] If gas is generated due to overcharging or malfunction of the secondary battery, the protruding portion is deformed upward by the pressure and separated from the subplate, while the safety vent is cut along the notch. The cut safety vent allows the gas to be released to the outside, preventing the secondary battery from exploding.

[0080] The cap-down may be located below the safety vent. The cap-down may have a first opening for exposing the protrusion of the safety vent and a second opening for gas discharge. An insulating member may be located between the safety vent and the cap-down to insulate them from each other.

[0081] The subplate may be located below the cap-down. The subplate is fixed to the underside of the cap-down so as to close the first opening of the cap-down, and the projection of the safety vent is fixed to the subplate. The first lead tab 35 drawn out from the electrode assembly 30 is fixed to the subplate. Thus, the cap-up, safety vent, cap-down, and subplate are electrically connectable to the first electrode 33 of the electrode assembly 30.

[0082] The insulating plate 37 may be positioned below the beading portion 43 so as to be in contact with the electrode assembly 30, and the insulating plate 37 is provided with a tab opening for pulling out the first lead tab 35. The cap assembly 50, electrically connected to the first electrode 33 by the first lead tab 35, faces the electrode assembly 30 across the insulating plate 37, and the insulating plate 37 can maintain insulation from the electrode assembly 30. On the other hand, another insulating plate 36 is included for insulation between the electrode assembly 30 and the bottom 41 of the case.

[0083] In this invention, the presence or absence of a fire is determined based on data transmitted via the cloud. Figure 5 is a conceptual diagram illustrating the ESS fire detection method utilizing the cloud service of this invention. In the following description, the method for detecting a fire in an ESS will be used as an example, but this invention can also be applied, for example, to detecting a fire in a battery pack installed in a vehicle.

[0084] The battery management system 510 is a system that monitors the battery status and performs diagnostic, control, communication, and protection functions. The battery management system 10 transmits battery status data, such as battery cell voltage, current, temperature, and alarm / protection occurrence information, to the data acquisition device 20. The data acquisition device 520 transmits the battery status data received from the battery management system 10 in the ESS to the cloud server 100. The event occurrence inspection program 200 analyzes the battery status data received from the battery management system via the cloud server 100 to determine whether or not a fire event has occurred. The event occurrence inspection program 200 may be a program executed within the cloud server 100, or it may be a program executed on a processor outside the cloud.

[0085] Figure 6 is a flowchart showing the procedure for determining whether or not a fire event has occurred according to one embodiment of the present invention. The event occurrence inspection program 200 receives battery status data received via the cloud server 100 (S110). The event occurrence inspection program 200 analyzes the battery status data to determine whether or not a fire has occurred (S120). The algorithm for determining whether or not a fire has occurred will be described later. If the event occurrence inspection program 200 determines that a fire has occurred, it notifies that a fire event has occurred (S130). The notification of a fire event may be sent, for example, by sending a text message, email, messenger message, etc., to a predetermined telephone number, email address, messenger address, etc.

[0086] Next, with reference to Figures 7 and 8, we will describe several algorithms for determining whether or not a fire has occurred.

[0087] When a battery fire occurs, some or all of the following phenomena may be observed:

[0088] -Cell voltage drop: When a fire occurs, a characteristic feature is observed where the battery vents open and the cell voltage drops.

[0089] - Cell temperature rise: A characteristic observed is that the voltage of the temperature sensor inside the battery rises due to the fire.

[0090] - Module temperature rise: A characteristic feature observed is that the temperature of the modules inside the battery rises due to the fire.

[0091] - Communication interruption: A characteristic observed is that communication with the module is interrupted due to explosions caused by fire.

[0092] Such phenomena can occur in situations other than fire, so judging events based on individual conditions may lead to false detections. For example, if a sensor that detects battery voltage malfunctions, diagnosing the event by only observing the cell voltage drop may result in a false detection. Therefore, this invention minimizes false detections by integrating multiple data points.

[0093] In this invention, the presence or absence of a fire is determined using all or part of the following events. -UVP (Under Voltage Protection): A flag is raised when a cell voltage drop occurs for a certain period of time or longer. -VIMBP (Voltage Imbalance Protection): A flag that is raised when voltage variations between cells persist for a certain period of time or longer. -OTA / OTP (Over Temperature Alarm / Protection): This flag is raised when the temperature inside the module remains above a certain value, indicating that an alarm has occurred (OTA) or that a protective action has been taken (OTP). -RMA / RMP (Rack Module Communication Fail Alarm / Protection): This flag is raised when a communication error occurs between the rack BMS and the module BMS, indicating whether an alarm (RMA) has occurred or a protective action (RMP) has been taken. -PCB OTP: A flag that is raised when the PCB temperature of the module BMS is maintained above a certain value. -Current < C th : The current measured in the rack is lower than the threshold current C th If it is lower -MIN_CV < V th : The minimum cell voltage in the rack is lower than the threshold voltage V th If it is lower -MAX_T > T th : The maximum module temperature in the rack is higher than the threshold temperature T th If it is higher

[0094] Figure 7 is a flowchart showing a fire event occurrence determination algorithm according to an embodiment of the present invention.

[0095] In Figure 7, it shows the case where when three AND conditions are satisfied and one of five OR conditions is satisfied, it is determined that a fire has occurred. The three AND conditions are UVP, VIMBP, MIN_CV < V th and the five OR conditions are OTA, OTP, RMA, RMP, PCB OTP. That is, in Figure 7, when (UVP & VIMBP & (MIN_CV < V th )) & (OTA | OTP | RMA | RMP | PCB OTP), it is determined that a fire has occurred.

[0096] That is, a cell voltage drop occurs for a certain period of time or more (step S121), the voltage variation between cells is maintained for a certain period of time or more (step S122), and the minimum cell voltage in the rack is the threshold voltage V thIf all three AND conditions are satisfied, including being lower (step S123), and one of the following five OR conditions is satisfied: an alarm (OTA) is issued indicating that the temperature inside the module has been maintained above a certain value (step S124), a protective action (OTP) is performed because the temperature inside the module has been maintained above a certain value (step S125), an alarm (RMA) is issued indicating a communication error between the rack BMS and the module BMS (step S126), a protective action (RMP) is performed because a communication error has occurred between the rack BMS and the module BMS (step S127), or the PCB temperature of the module BMS has been maintained above a certain value (PCB OTP) (step S128), then the event occurrence inspection program 200 determines that a fire has occurred in the ESS where the data originated and notifies the ESS that a fire event has occurred (step S130).

[0097] Threshold voltage V th This can be appropriately configured depending on the type of battery cell and the installation environment. For example, V th It may be 1V.

[0098] On the other hand, depending on the embodiment, it may be possible to determine that a fire event has occurred even if only the three AND conditions are satisfied. That is, steps S121 to S123 may be performed, and steps S124 to S128 may be omitted.

[0099] Furthermore, in some embodiments, it can be determined that a fire event has occurred if two of the three AND conditions and one of the OR conditions are satisfied. In other words, it can be determined that a fire event has occurred in the following three cases: (UVP&VIMBP)&(OTA|OTP|RMA|RMP|PCB OTP) (VIMBP&(MIN_CV <V th ))&(OTA|OTP|RMA|RMP|PCB OTP) (UVP&(MIN_CV <V th ))&(OTA|OTP|RMA|RMP|PCB OTP)

[0100] Furthermore, in some embodiments, it can be determined that a fire event has occurred if two of the three AND conditions are met. That is, it can be determined that a fire event has occurred in the following three cases: UVP&VIMBP VIMBP&(MIN_CV <V th ) UVP&(MIN_CV <V th )

[0101] On the other hand, depending on the embodiment, the received data can be stored in the cloud, and the system can be configured to determine the activation / deactivation decision factors based on the changes in the characteristics of the data stored in the cloud. Furthermore, the system can be configured to adjust the priority confirmation order in the confirmation order between decision factors based on the changes in the default data.

[0102] Figure 8 is a flowchart showing a fire event occurrence determination algorithm according to another embodiment of the present invention.

[0103] Figure 8 shows a case where a fire is determined to have occurred if four AND conditions are met. The four AND conditions are ((MIN_CV <V th )&(Current <C th )&(MAX_T>T th )&(MIN_CV and MAX_T measurement modules are the same module)).

[0104] In other words, the lowest cell voltage in the rack is the threshold voltage V th Lower (step S221), the current measured in the rack is the threshold current C th Lower (step S222), the maximum module temperature in the rack is below the threshold temperature T. thIf the value is higher (step S223), and steps S221 and S223 occur in the same module (step S224), the event occurrence inspection program 200 determines that a fire has occurred in the ESS where the data originated, and notifies the ESS that a fire event has occurred (step S130).

[0105] Threshold voltage V th , threshold current C th , threshold temperature T th This can be appropriately configured depending on the type of battery cell and the installation environment. For example, V th is 1V, C th 2A, T th It may be 40 degrees Celsius.

[0106] Depending on the embodiment, the fire alarm level can be configured to vary depending on the event that occurs. Such embodiments will be explained with reference to Figure 9.

[0107] The event occurrence inspection program 200 receives battery status data via the cloud server 100 (S310). The event occurrence inspection program 200 analyzes the battery status data to determine whether all the conditions for a fire event to occur are met (S320). The algorithm used to determine whether a fire has occurred can be the algorithm shown in Figure 7 or Figure 8. If the event occurrence inspection program 200 determines that a fire has occurred, it notifies that a fire event has occurred (S340). The notification of a fire event may also be sent, for example, by sending a text message, email, or messenger message to a predetermined telephone number, email address, or messenger address to a specific ESS informing it that a fire has occurred. Even if all the conditions for a fire event to occur are not met, if some of the predetermined conditions are met (S330), a preliminary alarm can be issued (S350). The preliminary alarm may also be sent, for example, by sending a text message, email, or messenger message to a predetermined telephone number, email address, or messenger address to a specific ESS informing it that a preliminary alarm has been issued.

[0108] In one embodiment, the system can be configured to issue a preliminary alarm when two of the three AND conditions in the embodiment of Figure 7 are satisfied. Alternatively, it may be configured to issue a preliminary alarm when two AND conditions and one OR condition are satisfied. In another embodiment, the system can be configured to issue a preliminary alarm when three of the four AND conditions in the embodiment of Figure 8 are satisfied.

[0109] The above explanation uses the detection of a fire in an ESS (Energy Storage System) as an example, but the present invention can also be applied to, for example, the detection of a fire in a battery pack installed in a vehicle. In this case, by replacing "rack" with "battery pack" in the above explanation, the same algorithm can be used to detect the fire.

[0110] Figure 10 is a block diagram showing a computer system for implementing the method according to an embodiment of the present invention.

[0111] Referring to Figure 10, the computer system 1300 may include at least one of a processor 1310 communicating via a bus 1370, a memory 1330, an input interface device 1350, an output interface device 1360, and a storage device 1340. The computer system 1300 may also include a network-connected communication device 1320. The processor 1310 may be a central processing unit (CPU) or a semiconductor device that executes instructions stored in the memory 1330 or the storage device 1340. The memory 1330 and the storage device 1340 may include various forms of volatile or non-volatile storage media. For example, the memory may include ROM (read-only memory) and RAM (random access memory). In the embodiments described herein, the memory may be located inside or outside the processor, and the memory may be connected to the processor via various means already known. The memory may be various forms of volatile or non-volatile storage media, for example, the memory may include read-only memory (ROM) or random access memory (RAM).

[0112] Embodiments of the present invention may be implemented as a computer implementation or as a non-temporary computer-readable medium storing computer-executable instructions. In one embodiment, when executed by a processor, the computer-readable instructions can be carried out by at least one of the methods described herein.

[0113] The communication device 1320 can transmit or receive wired or wireless signals.

[0114] Furthermore, the methods according to the embodiments of the present invention may be implemented in the form of program instructions delivered via various computer means and recorded on a computer-readable medium.

[0115] The computer-readable medium may include program instructions, data files, data structures, etc., either alone or in combination. The program instructions recorded on the computer-readable medium may be specifically designed and configured for embodiments of the present invention, or may be publicly known and available to the average person in the field of computer software. The computer-readable recording medium may include hardware devices configured to store and execute program instructions. For example, the computer-readable recording medium may be magnetic media such as hard disks, floppy disks, and magnetic tapes; optical media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; ROMs, RAMs, flash memory, etc. The program instructions may include not only machine code generated by a compiler, but also high-level language code executable by a computer via an interpreter or the like.

[0116] The following describes materials that can be used in the secondary battery according to the present invention.

[0117] As the positive electrode active material, compounds capable of reversible intercalation and deintercalation of lithium (lithiated intercalation compounds) can be used. Specifically, one or more composite oxides of lithium with metals selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0118] The aforementioned composite oxide may be a lithium transition metal composite oxide, and specific examples include lithium nickel oxide, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate compound, cobalt-free nickel-manganese oxide, or a combination thereof.

[0119] As an example, compounds represented by any one of the following chemical formulas can be used: LiaA1-bXbO2-cDc(0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05);LiaMn2-bXbO4-cDc(0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.05);LiaNi1-b-cCobXcO2-αDα(0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.5, 0<α<2);LiaNi1-b-cMnbXcO2-αDα(0.90≦a≦1.8, 0≦b≦0.5, 0≦c≦0.5, 0<α<2);LiaNibCocL1dGeO2(0.90≦a≦1.8, 0≦b≦0.9, 0≦ c≦0.5, 0≦d≦0.5, 0≦e≦0.1);LiaNiGbO2(0.90≦a≦1.8, 0.001≦b≦0.1);Lia CoGbO2(0.90≦a≦1.8, 0.001≦b≦0.1);LiaMn1-bGbO2(0.90≦a≦1.8, 0.001≦ b≦0.1);LiaMn2GbO4(0.90≦a≦1.8, 0.001≦b≦0.1);LiaMn1-gGgPO4(0.90 ≦a≦1.8, 0≦g≦0.5); Li(3-f)Fe2(PO4)3 (0≦f≦2); LiaFePO4 (0.90≦a≦1.8).

[0120] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; L1 is Mn, Al, or a combination thereof.

[0121] A positive electrode for a lithium secondary battery may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer may include a positive electrode active material and further include a binder and / or a conductive material.

[0122] The content of the positive electrode active material is 90% to 99.5% with respect to 100% by weight of the positive electrode active material layer, and the contents of the binder and the conductive material may each be 0.5% to 5% with respect to 100% by weight of the positive electrode active material layer.

[0123] As the current collector, Al can be used, but it is not limited thereto.

[0124] The negative electrode active material includes a substance capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a substance capable of doping and undoping lithium, or a transition metal oxide.

[0125] Examples of the substance capable of reversibly intercalating / deintercalating lithium ions include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon, hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0126] As the substance capable of doping and undoping lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used. The Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-based alloy, or a combination thereof.

[0127] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in a form in which amorphous carbon is coated on the surface of silicon particles.

[0128] The silicon-carbon composite may further contain crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles, and an amorphous carbon coating layer located on the surface of the core.

[0129] A negative electrode for a lithium secondary battery includes a current collector and a negative electrode active material layer located on the current collector. The negative electrode active material layer includes a negative electrode active material and may further include a binder and / or a conductive material.

[0130] For example, the negative electrode active material layer may contain 90% to 99% by weight of the negative electrode active material, 0.5% to 5% by weight of the binder, and 0% to 5% by weight of the conductive material.

[0131] The binder can be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. When an aqueous binder is used as the negative electrode binder, it may further contain a cellulosic compound capable of imparting viscosity.

[0132] As the negative electrode current collector, copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof can be selected.

[0133] The electrolyte for lithium secondary batteries contains a non-aqueous organic solvent and a lithium salt.

[0134] The non-aqueous organic solvent acts as a medium through which ions involved in the electrochemical reaction of the battery can move.

[0135] The non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, an aprotic solvent, or a combination thereof, and can be used alone or in a mixture of two or more.

[0136] Furthermore, when using carbonate-based solvents, cyclic carbonates and linear carbonates can be mixed and used together.

[0137] Depending on the type of lithium secondary battery, a separator may be present between the positive and negative electrodes. Such separators can be polyethylene, polypropylene, polyvinylidene fluoride, or multilayer films of two or more layers thereof.

[0138] The separator may include a porous substrate and a coating layer containing organic, inorganic, or a combination thereof located on one or both sides of the porous substrate.

[0139] The aforementioned organic material may include a polyvinylidene fluoride polymer or a (meth)acrylic polymer.

[0140] The inorganic material may include, but is not limited to, inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0141] The organic and inorganic materials can exist mixed together in a single coating layer, or they can exist in a form in which a coating layer containing organic materials and a coating layer containing inorganic materials are stacked on top of each other.

[0142] Figure 11 is an illustrative diagram of a secondary battery module in which secondary batteries are arranged using electrode assemblies manufactured according to the present invention. Due to the increasing capacity of secondary batteries for propulsion systems such as electric vehicles, a secondary battery module is manufactured by arranging and connecting a large number of secondary battery cells in the lateral and / or vertical directions. A large number of secondary batteries are arranged in the space between a pair of opposing end plates 68a, 68b and a pair of opposing side plates 69a, 69b. The arrangement of the secondary batteries can be designed in terms of arrangement direction and number to obtain desired voltage and current specifications.

[0143] Figure 12 is an illustrative diagram of a secondary battery pack 70 configured for application to an actual product (e.g., an automobile) using the secondary battery module illustrated in Figure 11. The secondary battery pack can be manufactured by housing a number of secondary battery modules in a pack housing designed for installation in an actual product. The pack housing may include fastening and electrical lead-out sections necessary for installation in the product. For illustrative purposes, Figure 12 omits the illustration of busbars for the electrical connection of the secondary batteries, cooling units, external terminals, and other related elements.

[0144] The secondary battery pack can be mounted on an automobile. The automobile may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The automobile may be a four-wheel drive or two-wheel drive vehicle. Figure 13 is a diagram illustrating an automobile including the secondary battery pack illustrated in Figure 12. Figure 13 illustrates that a secondary battery pack 70 according to one embodiment of the present invention is mounted on the underside of the body of an automobile V. The automobile V operates by receiving power from the secondary battery pack 70 according to one embodiment of the present invention.

[0145] Although the present invention has been described above with limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and that various modifications and variations are possible within the equivalent scope of the technical concept of the present invention and the claims described below by persons with ordinary skill in the art to which the present invention pertains. [Explanation of Symbols]

[0146] 10: BMS, 20: Data acquisition device, 100: Cloud server, 200: Event occurrence inspection program.

Claims

1. The first step is to receive battery status data from the battery management system via a server, The second step involves analyzing the received battery status data to determine whether or not a fire has occurred. A fire detection method for ESS (Emergency System) equipped with the following features.

2. The second step described above is: A fire is determined to have occurred when a cell voltage drop occurs for a certain period of time or longer, voltage variations between cells are maintained for a certain period of time or longer, and the lowest cell voltage in the rack is lower than the threshold voltage. The fire detection method for an ESS according to claim 1.

3. The second step described above is: All three conditions are satisfied: a cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the rack is lower than the threshold voltage. An alarm was triggered indicating that the temperature inside the module was maintained above a certain level. The temperature inside the module was maintained above a certain value, triggering a protective action. An alarm was issued indicating a communication error between the rack BMS and the module BMS. A communication error occurred between the rack BMS and the module BMS, triggering a protective action. The PCB temperature of the module BMS was maintained above a certain value. A fire is determined to have occurred if at least one of the following five conditions is met. The fire detection method for an ESS according to claim 1.

4. The second step described above is: A fire is determined to have occurred if at least two of the following three conditions are met: a cell voltage drop occurs for a certain period of time or longer, voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the rack is lower than the threshold voltage. The fire detection method for an ESS according to claim 1.

5. The second step described above is: At least two of the following three conditions are satisfied: a cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the rack is lower than the threshold voltage. An alarm was triggered indicating that the temperature inside the module was maintained above a certain level. The temperature inside the module was maintained above a certain value, triggering a protective action. An alarm was issued indicating a communication error between the rack BMS and the module BMS. A communication error occurred between the rack BMS and the module BMS, triggering a protective action. The PCB temperature of the module BMS was maintained above a certain value. A fire is determined to have occurred if at least one of the following five conditions is met. The fire detection method for an ESS according to claim 1.

6. The second step described above is: A fire is determined to have occurred if the lowest cell voltage in the rack is lower than the threshold voltage, the current measured in the rack is lower than the threshold current, and the maximum module temperature in the rack is higher than the threshold temperature, and both the lowest cell voltage in the rack being lower than the threshold voltage and the maximum module temperature being higher than the threshold temperature occur in the same module. The fire detection method for an ESS according to claim 1.

7. If a fire is detected, the third step is to notify that a fire event has occurred. The ESS fire detection method according to claim 1, further comprising the above.

8. The server mentioned above is a cloud server. The fire detection method for an ESS according to claim 1.

9. The first step is to receive battery status data from the battery management system via a server, The second step involves analyzing the received battery status data to determine whether or not a fire has occurred. A fire detection method for a battery pack equipped with the following features.

10. The second step described above is: A fire is determined to have occurred if a cell voltage drop occurs for a certain period of time or longer, voltage variations between cells are maintained for a certain period of time or longer, and the lowest cell voltage in the battery pack is lower than the threshold voltage. The method for detecting a fire in a battery pack according to claim 9.

11. The second step described above is: All three conditions are met: a cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the battery pack is lower than the threshold voltage. An alarm was triggered indicating that the temperature inside the module was maintained above a certain level. The temperature inside the module was maintained above a certain value, triggering a protective action. An alarm was issued indicating a communication error between the battery pack BMS and the module BMS. A communication error occurred between the battery pack BMS and the module BMS, triggering a protective action. The PCB temperature of the module BMS was maintained above a certain value. A fire is determined to have occurred if at least one of the following five conditions is met. The method for detecting a fire in a battery pack according to claim 9.

12. The second step described above is: A fire is determined to have occurred if at least two of the following three conditions are met: a cell voltage drop occurs for a certain period of time or longer, voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the battery pack is lower than the threshold voltage. The method for detecting a fire in a battery pack according to claim 9.

13. The second step described above is: At least two of the following three conditions are satisfied: a cell voltage drop occurs for a certain period of time or longer, the voltage variation between cells is maintained for a certain period of time or longer, and the lowest cell voltage in the battery pack is lower than the threshold voltage. An alarm was triggered indicating that the temperature inside the module was maintained above a certain level. The temperature inside the module was maintained above a certain value, triggering a protective action. An alarm was issued indicating a communication error between the battery pack BMS and the module BMS. A communication error occurred between the battery pack BMS and the module BMS, triggering a protective action. The PCB temperature of the module BMS was maintained above a certain value. A fire is determined to have occurred if at least one of the following five conditions is met. The method for detecting a fire in a battery pack according to claim 9.

14. The second step described above is: A fire is determined to have occurred if the lowest cell voltage in the battery pack is lower than the threshold voltage, the current measured in the battery pack is lower than the threshold current, and the maximum module temperature in the battery pack is higher than the threshold temperature, and both the lowest cell voltage in the battery pack being lower than the threshold voltage and the maximum module temperature being higher than the threshold temperature occur in the same module. The method for detecting a fire in a battery pack according to claim 9.

15. If a fire is detected, the third step is to notify that a fire event has occurred. The method for detecting a fire in a battery pack according to claim 9, further comprising:

16. The server mentioned above is a cloud server. The method for detecting a fire in a battery pack according to claim 9.

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