Battery fire prediction method and battery system providing the method

Abstract

The present invention relates to a method for predicting the occurrence of a battery fire and a battery system that provides the method. The battery system of the present invention includes a battery module including a plurality of battery cells, and wakes up every first cycle to determine the presence or absence of the occurrence of a first fire event in the battery module. When the battery module is determined to be in a stable state according to a predetermined safety standard, it wakes up every second cycle that is longer than the first cycle by a predetermined period to determine the presence or absence of the occurrence of the first fire event. A slave BMS (Battery Management System) that performs a second low power mode, and a master BMS that enters a sleep mode after transmitting a first control signal instructing entry into the first low power mode to the slave BMS in a state where the battery module does not supply power to an external device.

Description

Technical Field

[0001] Cross - reference to Related Applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2022 - 0098831, filed on August 8, 2022, and all of the contents disclosed in the document of the Korean Patent Application are incorporated herein by reference.

[0003] The present invention relates to a method for predicting the occurrence of a battery fire and a battery system providing the method.

Background Art

[0004] When a fire occurs in an electric vehicle, unlike an internal combustion engine vehicle, it is extremely difficult to extinguish until it burns out completely. Also, unlike an internal combustion engine vehicle, an electric vehicle has the characteristic of burning instantly, and if the rescue time is delayed, the human life damage can be significant. The reason for such a situation is due to the "Thermal Runaway" phenomenon in which the temperature of the battery rises above 1,000 degrees.

[0005] Research and development are being carried out to detect the battery thermal runaway phenomenon in advance. A method of collecting battery data such as the temperature and voltage of the battery and analyzing the change in the collected battery data to predict the battery thermal runaway phenomenon in advance is widely used.

[0006] However, in the charging state where the battery is charged by an external power source, the BMS (Battery Management System) is in the Sleep Mode or Shut Down Mode. Therefore, the BMS cannot collect battery data and predict the battery thermal runaway in advance. That is, the battery thermal runaway phenomenon cannot be detected in advance, and most of the fires related to the battery occur when the battery is being charged.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention provides a method for predicting the occurrence of a battery fire and a method thereof, even when the battery is charged with the power of an external charger, or when the upper system (for example, an automobile, an energy storage system, etc.) equipped with the battery is not operating and the battery management system (BMS) is in the sleep mode.

Means for Solving the Problems

[0008] A battery system according to one feature of the present invention includes a battery module including a plurality of battery cells, a first low power mode that wakes up every first cycle to determine the presence or absence of the occurrence of a first fire event of the battery module, and when the battery module is determined to be in a stable state according to a predetermined safety standard, a slave BMS (Battery Management System) that wakes up every second cycle that is longer than the first cycle by a predetermined period to determine the presence or absence of the occurrence of the first fire event, and a master BMS that enters the sleep mode after transmitting a first control signal instructing entry into the first low power mode to the slave BMS in a state where the battery module does not supply power to an external device.

[0009] The slave BMS can compare battery data including information on the state of the battery module with a predetermined reference value to determine the presence or absence of the occurrence of the first fire event.

[0010] The slave BMS can determine that the battery module is in a stable state if the first fire event does not occur during a period when the total number of wake-ups according to the first cycle reaches a predetermined reference number of times.

[0011] When the first fire event occurs, the master BMS wakes up and can determine the presence or absence of the occurrence of a second fire event according to a predetermined algorithm.

[0012] When the second fire event occurs, the master BMS can transmit a warning message corresponding to the occurrence of a fire in the battery module to a higher-level controller.

[0013] If the second fire event does not occur, the master BMS can enter the sleep mode after transmitting a second control signal instructing the slave BMS to enter the first low-power mode to the slave BMS.

[0014] A method for predicting a fire in a battery according to another feature of the present invention is a method for predicting the occurrence of a fire in a battery module, including a stage in which a slave BMS (Slave Battery Management System) that manages the battery module enters the sleep mode, a first low-power mode stage in which the slave BMS wakes up every first period to determine whether a first fire event has occurred in the battery module, and a second low-power mode stage in which, when the battery module is determined to be in a stable state according to a predetermined safety standard, the slave BMS wakes up every second period that is longer than the first period by a predetermined period to determine whether the first fire event has occurred.

[0015] The first low-power mode stage may include a stage of determining that the state of the battery module is a stable state if the first fire event does not occur during a period when the total number of wake-ups according to the first period reaches a predetermined reference number.

[0016] Each of the first low-power mode stage and the second low-power mode stage may include a stage in which the slave BMS compares battery data including information on the state of the battery module with a predetermined reference value to determine whether the first fire event has occurred.

[0017] In each of the first low-power mode stage and the second low-power mode stage, when the first fire event occurs, the master BMS (Master Battery Management System) that controls the slave BMS wakes up and determines whether a second fire event occurs according to a predetermined algorithm.

[0018] In each of the first low-power mode stage and the second low-power mode stage, when the second fire event occurs, the master BMS may further include a stage of transmitting a warning message corresponding to the occurrence of a fire in the battery module to a higher-level controller.

[0019] If the second fire event does not occur in the second low-power mode stage, after the master BMS transmits a second control signal instructing entry into the first low-power mode to the slave BMS, the second low-power mode stage may further include a stage of entering the sleep mode.

Advantages of the Invention

[0020] Embodiments of the present invention can predict the occurrence of a battery fire and reduce human life and property damage even when the battery management system (BMS) is in the sleep mode.

[0021] Embodiments of the present invention can save the power consumption of the battery management system (BMS) by adjusting the wake-up cycle of the slave BMS to be short or long according to the safety state of the battery.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0023] Hereinafter, with reference to the accompanying drawings, the embodiments disclosed in this specification will be described in detail. However, the same or similar components are given the same or similar drawing numbers, and duplicate descriptions thereof are omitted. The suffixes “module” and / or “section” for the components used in the following description are given or mixed only for the ease of preparing the specification, and do not have meanings or roles that are distinguishable from each other by themselves. Further, when explaining the embodiments disclosed in this specification, if it is determined that the specific description of such known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof is omitted. Furthermore, the attached drawings are only for facilitating the understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and it should be understood that all modifications, equivalents or alternatives included in the idea and technical scope of the present invention are included.

[0024] Terms including ordinal numbers such as first, second, etc. can be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another component.

[0025] When it is mentioned that a certain component is “connected to” or “connected with” another component, it should be understood that it may be directly connected to or connected with the other component, but other components may exist in the middle. On the contrary, when it is mentioned that a certain component is “directly connected to” or “directly connected with” another component, it should be understood that no other component exists in the middle.

[0026] In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and it should be understood that they do not preclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0027] FIG. 1 is a block diagram illustrating a battery system according to an embodiment.

[0028] Referring to FIG. 1, the battery system 1 includes a battery 10, a relay 20, and a Battery Management System (BMS) 30.

[0029] Referring to FIG. 1, the battery 10 is connected between two output terminals OUT1 and OUT2 of the battery system 1. The relay 20 is connected between the positive electrode of the battery system 1 and the first output terminal OUT1. The configuration shown in FIG. 1 and the connection relationships between the configurations are examples, and the invention is not limited thereto.

[0030] The battery 10 can include at least one battery module B. The battery module B can include a plurality of battery cells electrically connected in series and / or in parallel. FIG. 1 shows a plurality of battery modules B_1, B_2,..., B_n, but is not limited thereto, and the battery 10 can include one battery module B_1. Also, FIG. 1 shows that a plurality of battery cells included in the battery module B are connected in series, but is not limited thereto, and the plurality of battery cells can be connected in series and / or in parallel. In one embodiment, the battery cell may be a rechargeable secondary battery.

[0031] The battery 10 may be in a discharge state, a charge state, or an idle state. The discharge state may be a state in which the battery 10 supplies power to an external device and discharges. The charge state may be a state in which the battery 10 receives power from an external device and is charged. The idle state may be a state in which the battery 10 and the external device are electrically connected but there is no power transmission. At this time, the external device may be a charger in the charge state and a load in the discharge state.

[0032] In the discharge state of the battery 10, the battery management system (BMS) 30 can operate in an operating mode that manages the battery system 1 according to a preset logic. In the charge state and the idle state of the battery 10, the battery management system (BMS) 30 can operate in a sleep mode that does not perform the preset logic. Conventionally, in the charge state and the idle state of the battery 10, the battery management system (BMS) 30 was in a sleep mode that did not perform any operation including prediction of a fire event of the battery 10. As a result, even if a fire of the battery 10 such as Thermal Runaway occurred in the charge state and the idle state of the battery 10, it was not prepared in advance.

[0033] According to an embodiment, in the charge state and the idle state of the battery 10, the battery management system (BMS) 30 can operate in a low power mode. The low power mode is a mode in which the battery management system (BMS) 30 in the sleep mode wakes up every first cycle of a short period or every second cycle of a long period according to the safety state of the battery and predicts a fire event of the battery 10.

[0034] Relay 20 electrically connects or disconnects the battery system 1 and an external device under the control of the battery management system 30. When relay 20 is turned on, the battery system 1 and the external device are electrically connected, and charging or discharging is performed. When relay 20 is turned off, the battery system 1 and the external device are electrically disconnected.

[0035] The battery management system (BMS) 30 includes a slave BMS (P_BMS) and a master BMS (R_BMS).

[0036] The slave BMS (P_BMS) can monitor and manage battery module B. The slave BMS (P_BMS) is electrically connected to each of a plurality of battery cells via wiring and can collect battery data. At this time, the battery data can include at least one of the cell voltage, cell current, and cell temperature of each of the plurality of battery cells indicating the state of battery module B. Also, the battery data can include at least one of the module voltage, which is the voltage across battery module B, the module current, which is the current flowing through battery module B, and the module temperature, which is the temperature of battery module B. In one embodiment, battery module B and slave BMS (P_BMS) may be composed of one battery pack. The battery management system (BMS) 30 can include a plurality of slave BMSs (P_BMS) corresponding to each of the plurality of battery modules B.

[0037] The master BMS (R_BMS) can communicate with a controller of a host system (hereinafter, host controller) in which the battery system 1 is mounted to transmit and receive various information, and can generally manage the battery management system (BMS) 30.

[0038] According to the embodiment, in the charged state and the resting state of the battery 10, under the control of the master BMS (R_BMS), the slave BMS (P_BMS) operates in the first low-power mode or the second low-power mode, and the master BMS (R_BMS) may operate in the sleep mode.

[0039] In the first low-power mode or the second low-power mode, the slave BMS (P_BMS) that was in the sleep mode wakes up every first cycle of a short period or every second cycle of a long period according to the stable state of the battery, and determines whether there is an occurrence of a first fire event of the battery 10. The sleep mode is a mode in which the master BMS (R_BMS) sleeps without performing preset logic unless the master BMS (R_BMS) receives an alarm message corresponding to the occurrence of the first fire event from the slave BMS (P_BMS).

[0040] Referring to FIG. 1, each of the plurality of slave BMSs (P_BMS_1, P_BMS_1,..., P_BMS_n) in the sleep mode wakes up every first cycle or every second cycle, collects battery data, compares the collected battery data with a first reference value, and can determine whether there is an occurrence of the first fire event. When at least one slave BMS (P_BMS) of the plurality of slave BMSs (P_BMS_1, P_BMS_1,..., P_BMS_n) transmits an alarm message corresponding to the occurrence of the first fire event to the master BMS (R_BMS), the master BMS (R_BMS) in the sleep mode can wake up.

[0041] FIG. 2 is a block diagram for explaining in detail the slave BMS and the master BMS of FIG. 1.

[0042] Referring to FIG. 2, according to one embodiment, each of a plurality of slave BMSs (P_BMS_1, P_BMS_2, …, P_BMS_n) can include a monitoring unit 311, a control unit 315, and a communication unit 313. According to another embodiment, in order to reduce the size of the battery management system (BMS) 30, each of the plurality of slave BMSs (P_BMS_1, P_BMS_2, …, P_BMS_n) may not include the control unit 315 and can include the monitoring unit 311 and the communication unit 313. At this time, each of the plurality of slave BMSs (P_BMS_1, P_BMS_2, …, P_BMS_n) can operate under the control of the master BMS (R_BMS).

[0043] Hereinafter, when indicating a specific slave BMS among the plurality of slave BMSs (P_BMS_1, P_BMS_2, …, P_BMS_n), the reference numeral “P_BMS_k” is used. Also, when indicating a specific battery module among the plurality of battery modules B_1, B_2, …, B_n, the reference numeral “B_k” is used.

[0044] The monitoring unit 311 can be electrically connected to each of the plurality of battery cells included in the battery module B_k via wiring to collect battery data. For example, the monitoring unit 311 may be composed of a BMIC (Battery Management IC), an ASIC (Application-specific IC), or the like.

[0045] The control unit 315 can generally control the slave BMS (P_BMS_k). For example, the control unit 315 may be composed of an MCU (micro controller unit) or the like.

[0046] In an embodiment where the slave BMS (P_BMS_k) includes the control unit 315, the slave BMS (P_BMS_k) wakes up every first cycle or second cycle. The monitoring unit 311 collects battery data and transmits it to the control unit 315. The control unit 315 can compare the battery data with the first reference value to determine the occurrence of the first fire event.

[0047] In another embodiment where the slave BMS (P_BMS_k) does not include the control unit 315, the monitoring unit 311 wakes up every first cycle or second cycle, collects battery data, compares the collected battery data with the first reference value, and can determine the occurrence of the first fire event.

[0048] The communication unit 313 can communicate with the master BMS (R_BMS) either wired or wirelessly. According to the embodiment, the communication unit 313 can transmit the battery data and an alarm message corresponding to the occurrence of the first fire event to the master BMS (R_BMS). FIGS. 1 and 2 show the communication method between the communication unit 313 and the master BMS (R_BMS) as CAN communication using CAN BUS, but it is not limited thereto, and it can include a communication module that provides various forms of wired communication or wireless communication methods.

[0049] The master BMS (R_BMS) can include a master communication unit 331, a master storage unit 333, and a master control unit 335.

[0050] The master communication unit 331 can communicate with a plurality of slave BMSs (P_BMS_1, P_BMS_2,..., P_BMS_n) either wired or wirelessly. For example, the master communication unit 331 may be composed of a communication bridge IC or the like.

[0051] According to an embodiment, when the master communication unit 331 receives an alarm message from at least one slave BMS (P_BMS_k), it can wake up the master control unit 335. For example, the master communication unit 331 can wake up the master control unit 335 via an INTR (interrupt) line.

[0052] The master storage unit 333 can store at least one algorithm for predicting the occurrence of a fire in the battery 10. For example, the algorithm may be an algorithm that can be precisely predicted a predetermined time before the occurrence of thermal runaway or the like. Further, the master storage unit 333 can store the battery data received from the slave BMS (P_BMS_k).

[0053] The master control unit 335 generally controls the battery system 1. For example, the master control unit 335 may be composed of an MCU (micro controller unit) or the like. When receiving an alarm message via the master communication unit 331, the master control unit 335 can wake up and determine the presence or absence of the occurrence of a second fire event by a predetermined algorithm.

[0054] According to an embodiment, in the sleep mode, the slave BMS (P_BMS_k) wakes up at a predetermined period and determines the presence or absence of the occurrence of a first fire event in a simple method of comparing battery data with a reference value. When the first fire event occurs, the master BMS (R_BMS) wakes up and determines the presence or absence of the occurrence of a second fire event by a precise method using an algorithm.

[0055] As a result of the experiment, in an embodiment where the slave BMS (P_BMS_k) does not include the control unit 315, when the slave BMS (P_BMS_k) wakes up in the first period (e.g., 1 second) to predict the occurrence of the first fire event, the monitoring unit 311 consumes power of 80 μA / 1 sec, and the communication unit 313 consumes power of 12 μA / 1 sec. Also, when the slave BMS (P_BMS_k) wakes up in the second period (e.g., 32 seconds) to predict the occurrence of the first fire event, the monitoring unit 311 consumes power of 12 μA / 32 sec, and the communication unit 313 consumes power of 1 μA / 32 sec. The power consumption can be further reduced when the wake-up period is adjusted according to the state of the battery 10 rather than when the slave BMS (P_BMS_k) wakes up at a fixed period.

[0056] FIG. 3 is a flowchart for explaining a battery fire prediction method according to an embodiment, and FIG. 4 is a flowchart for explaining in detail the first low power mode stage S200 and the second low power mode stage S300 of FIG. 3.

[0057] First, referring to FIG. 3, the master BMS (R_BMS) determines to enter the low power mode of the battery management system (BMS) 30 (S100).

[0058] The master BMS (R_BMS) may receive information from a controller of the electric vehicle (hereinafter referred to as the upper controller) regarding whether the electric vehicle is in an operating state where it operates using the power of the battery 10, a charging state where the electric vehicle is connected to an external charger, or a parking state where the operation of the electric vehicle is interrupted. Based on the information transmitted from the upper controller, the master BMS (R_BMS) can control the battery management system (BMS) 30 in an operating mode or a low power mode. Although described as an example of an electric vehicle which is an example of an upper system, the present invention is not limited thereto, and the content described below is applicable to all kinds of upper systems in which the battery system 1 is mounted.

[0059]

Table 1

[0060] The above Table 1 is an example for explaining the mode executed by the battery management system (BMS) 30 according to the state of the electric vehicle and the battery 10.

[0061] For example, referring to Table 1, when the electric vehicle is in an operating state where it uses the power of the battery 10, the battery 10 may be in a discharge state where it supplies power to the electric vehicle. At this time, the battery management system (BMS) 30 can operate in an operating mode for managing the battery system 1 according to a preset logic. The preset logic may include monitoring of the battery 10, cell balancing of the battery 10, prediction of ignition events of the battery 10, and switching control of the relay 20.

[0062] As another example, referring to Table 1, in the charge state where an electric vehicle charges the battery 10 with the power of an external charger (not shown) and the parking state where the power of the battery 10 is not used, the battery management system (BMS) 30 can operate in a low power mode.

[0063] The sleep mode may be a mode in which power is not used without performing preset logic. The low power mode can be a mode in which it wakes up at a predetermined period in the sleep mode and predicts the occurrence of a fire event among the preset logic, and consumes a predetermined amount of power.

[0064] Specifically, in the low power mode of the battery management system (BMS) 30, the slave BMS (P_BMS_k) may be operated in the first low power mode or the second low power mode, and the master BMS (R_BMS) may be operated in the sleep mode.

[0065] The first low power mode or the second low power mode is a mode in which the slave BMS (P_BMS_k) in the sleep mode wakes up every predetermined period (the first period or the second period) to determine the presence or absence of the occurrence of the first fire event of the battery 10. The sleep mode is a mode in which the master BMS (R_BMS) sleeps without performing preset logic. However, when the master BMS (R_BMS) in the sleep mode receives an alarm message corresponding to the occurrence of the first fire event from the slave BMS (P_BMS_k), the master BMS (R_BMS) can wake up and determine the presence or absence of the occurrence of the second fire event.

[0066] Next, when the master BMS (R_BMS) determines to enter the low power mode of the battery management system (BMS) 30 (S100), the slave BMS (P_BMS_k) executes the first low power mode (S200).

[0067] According to the embodiment, in the charging state or the resting state of the battery 10 where the battery 10 does not supply power to an external device, the master BMS (R_BMS) can transmit a first control signal instructing entry into the first low-power mode to the slave BMS (P_BMS_k).

[0068] The first low-power mode may be a mode in which the slave BMS (P_BMS_k) in the sleep mode wakes up every first period of a short cycle to determine whether a first fire event of the battery 10 occurs. For example, the first period may be preset and stored in the slave BMS (P_BMS_k). As another example, the first period may be transmitted from the master BMS (R_BMS) to the slave BMS (P_BMS_k) at the S100 stage.

[0069] Referring to FIG. 4, at the S200 stage, first, the slave BMS (P_BMS_k) and the master BMS (R_BMS) enter the sleep mode (S210).

[0070] For example, after transmitting the first control signal to the slave BMS (P_BMS_k), the master BMS (R_BMS) itself can enter the sleep mode. In the first low-power mode, the slave BMS (P_BMS_k) maintains the sleep mode until the first period arrives. At this time, the first period can be determined by experiments as an optimal period that can improve the accuracy of predicting the ignition event of the battery 10 while reducing the power consumption of the slave BMS (P_BMS_k).

[0071] At the S200 stage, when the first period arrives, the slave BMS (P_BMS_k) wakes up and determines whether a first fire event occurs (S220).

[0072] After wake-up, the slave BMS (P_BMS_k) can collect battery data. At this time, the battery data can include at least one of a cell voltage, a cell current, and a cell temperature that indicate the state of each of a plurality of battery cells. Further, the battery data can include at least one of a module voltage that is the voltage across the battery module B, a module current that is the current flowing through the battery module B, and a module temperature that is the temperature of the battery module B.

[0073] According to an embodiment, the slave BMS (P_BMS_k) can compare the battery data with a first reference value to determine whether a first fire event has occurred.

[0074] For example, if at least two of the plurality of cell voltages corresponding to each of the plurality of battery cells exceed a first reference value (e.g., 5V), the slave BMS (P_BMS_k) can determine that a first fire event has occurred in the battery module B. As another example, if the temperature of the battery module B exceeds a second reference value (e.g., 30°C), the slave BMS (P_BMS) can determine that a first fire event has occurred in the battery module B. However, it is not limited thereto, and the slave BMS (P_BMS_k) can determine whether a first fire event has occurred in various ways of comparing the battery data with the magnitude of the first reference value.

[0075] In step S200, when a first fire event occurs (S230, Yes), the master BMS (R_BMS) wakes up and determines whether a second fire event has occurred (S240).

[0076] According to the embodiment, when a first fire event occurs, the slave BMS (P_BMS_k) can transmit an alarm message to the master BMS (R_BMS). The alarm message can act as a trigger to wake up the master BMS (R_BMS) in the sleep mode. Also, the slave BMS (P_BMS_k) can transmit battery data to the master BMS (R_BMS) together with the alarm message.

[0077] When the master communication unit 331 receives an alarm message from at least one slave BMS (P_BMS_k), it can wake up the master control unit 335. For example, the master communication unit 331 can wake up the master control unit 335 via the INTR (interrupt) line.

[0078] According to the embodiment, the master BMS (R_BMS) can determine the occurrence of a second fire event by a predetermined algorithm. The method for determining the occurrence of the first fire event is simple but may be a fire prediction method with low prediction precision. The method for determining the occurrence of the second fire event is complex but may be a fire prediction method with high prediction precision. In the low-power mode according to the embodiment, the battery management system (BMS) 30 periodically determines the occurrence of the first fire event to reduce power consumption, and when the first fire event occurs, it determines the occurrence of the second fire event to improve the prediction precision of the fire occurrence of the battery 10. At this time, the algorithm is not limited to a specific method and can include various known methods capable of predicting the fire occurrence of the battery 10.

[0079] In step S200, when a second fire event occurs (S250, Yes), the master BMS (R_BMS) transmits a warning message to the upper controller (S260).

[0080] For example, until the master BMS (R_BMS) receives a response message to the warning message from the upper controller, the master BMS (R_BMS) can continue to transmit the warning message to the upper controller. At this time, the warning message may include materials and judgment bases based on the prediction of a fire occurring in the battery 10, etc.

[0081] In the S200 stage, if the first fire event does not occur (S230, No), or if the second fire event does not occur (S250, No), the slave BMS (P_BMS_k) determines the stability of the battery 10 according to a predetermined safety standard (S270).

[0082] For example, if the first fire event does not occur (S230, No), the slave BMS (P_BMS_k) can determine the stability of the battery 10 according to the safety standard. At this time, the master BMS (R_BMS) may continue to be in the sleep mode.

[0083] As another example, if the second fire event does not occur (S250, No), the master BMS (R_BMS) can transmit the judgment result of the second fire event to the slave BMS (P_BMS_k). Then, the slave BMS (P_BMS_k) can determine the stability of the battery 10 according to the safety standard. However, it is not limited to this, and the master BMS (R_BMS) can determine the stability of the battery 10 according to the safety standard.

[0084] The safety standard can include predetermined conditions capable of determining that the state of the battery 10 is stable. For example, the safety standard can include the condition that the first fire event does not occur during 20 repetitions of the wake-up cycle according to the first period going back based on the judgment time point. However, it is not limited to this, and the safety standard can include various conditions capable of determining that the state of the battery 10 is stable.

[0085] In the S200 stage, if the safety standards are not met (S270, No), the slave BMS (P_BMS_k) can repeat from the S210 stage.

[0086] As described above, the subject for judging whether the safety standards are met is explained as the slave BMS (P_BMS_k), but it is not limited thereto, and the master BMS (R_BMS) can also judge whether the safety standards are met.

[0087] Next, when the safety standards are met (S270, Yes), the slave BMS (P_BMS_k) executes the second low-power mode (S300).

[0088] The second low-power mode may be a mode in which the slave BMS (P_BMS_k) in the sleep mode wakes up every second long-term cycle to determine whether the first fire event of the battery 10 occurs. For example, the second cycle may be preset and stored in the slave BMS (P_BMS_k). As another example, the second cycle may be transmitted from the master BMS (R_BMS) to the slave BMS (P_BMS_k) together with the sleep command in the S100 stage.

[0089] For example, the second period can be set to a predetermined multiple of the first period, but is not limited thereto. As a result of experiments, when the slave BMS (P_BMS_k) wakes up at a 1-second period to predict the occurrence of a fire event, the monitoring unit 311 consumes power of 80 μA / 1 sec, and the communication unit 313 consumes power of 12 μA / 1 sec. Also, when the slave BMS (P_BMS_k) wakes up at a 32-second period to predict the occurrence of a fire event, the monitoring unit 311 consumes power of 12 μA / 32 sec, and the communication unit 313 consumes power of 1 μA / 32 sec (however, depending on various set values of the battery system, the power consumption may be different). Compared with the case where the slave BMS (P_BMS_k) wakes up at a fixed period, when the slave BMS (P_BMS_k) wakes up at a short-term period or a long-term period according to the stable state of the battery 10, it is possible to reduce the power consumption while ensuring the safety of the battery 10.

[0090] In step S300, first, the slave BMS (P_BMS_k) and the master BMS (R_BMS) enter the sleep mode (S310).

[0091] For example, the master BMS (R_BMS) can instruct the slave BMS (P_BMS_k) to enter the second low-power mode. Then, the slave BMS (P_BMS_k) maintains the sleep mode until the second period arrives. And the master BMS (R_BMS) can enter the sleep mode itself.

[0092] As another example, after determining to enter the second low-power mode, the slave BMS (P_BMS_k) can enter the sleep mode itself. And the slave BMS (P_BMS_k) maintains the sleep mode until the second period arrives. And the master BMS (R_BMS) in the sleep mode can continue to maintain the sleep mode.

[0093] In the S300 stage, when the second cycle arrives, the slave BMS (P_BMS_k) wakes up and determines whether the first fire event has occurred (S320).

[0094] After waking up, the slave BMS (P_BMS_k) can collect battery data. At this time, the battery data can include at least one of the cell voltages, cell currents, and cell temperatures of a plurality of battery cells. Also, the battery data can include at least one of the module voltage which is the voltage across the battery module B, the module current which is the current flowing through the battery module B, and the module temperature which is the temperature of the battery module B.

[0095] According to the embodiment, the slave BMS (P_BMS_k) can compare the battery data with the first reference value to determine whether the first fire event has occurred. For example, if at least two of the cell voltages corresponding to a plurality of battery cells exceed the first reference value (e.g., 5V), the slave BMS (P_BMS) can determine that the first fire event has occurred. Also, the description regarding the S220 stage described above is similarly applicable to the S320 stage.

[0096] In the S300 stage, if the first fire event does not occur (S330, No), the slave BMS (P_BMS_k) can repeat from the S310 stage.

[0097] In the S300 stage, when the first fire event occurs (S330, Yes), the master BMS (R_BMS) wakes up and determines whether the second fire event has occurred (S340).

[0098] According to the embodiment, when a first fire event occurs, the slave BMS (P_BMS_k) can transmit an alarm message to the master BMS (R_BMS). The alarm message can act as a trigger to wake up the master BMS (R_BMS) in the sleep mode. Also, the slave BMS (P_BMS_k) can transmit battery data to the master BMS (R_BMS) together with the alarm message.

[0099] When the master communication unit 331 receives an alarm message from at least one slave BMS (P_BMS_k), it can wake up the master control unit 335. For example, the master communication unit 331 can wake up the master control unit 335 via an INTR (interrupt) line.

[0100] According to the embodiment, the master BMS (R_BMS) can determine the occurrence of a second fire event by a predetermined algorithm. The content described in step S240 is similarly applicable to step S340.

[0101] In step S300, when a second fire event occurs (S350, Yes), the master BMS (R_BMS) transmits a warning message to the upper controller (S360).

[0102] For example, the master BMS (R_BMS) can continue to transmit the warning message to the upper controller until a response message to the warning message is received from the upper controller. At this time, the warning message may include materials and bases for predicting the occurrence of a fire in the battery 10, etc.

[0103] In step S300, if a second fire event does not occur (S350, No), the master BMS (R_BMS) can control the slave BMS (P_BMS_k) to perform step S200.

[0104] If a second fire event does not occur, the master BMS (R_BMS) can transmit a second control signal instructing entry into the first low power mode to the slave BMS (P_BMS_k). Then, at step S210, the master BMS (R_BMS) can enter the sleep mode itself.

[0105] Even if a second fire event had occurred, since a first fire event has occurred, for the stability of the battery 10, the slave BMS (P_BMS_k) can wake up in the first cycle of the short period to determine the presence or absence of the occurrence of the first fire event.

[0106] As described above, the embodiments of the present invention have been described in detail, but the scope of the rights of the present invention is not limited thereto, and forms variously modified and improved by those having ordinary knowledge in the field to which the present invention pertains also belong to the scope of the rights of the present invention.

Claims

1. A battery module including a plurality of battery cells, A slave BMS that wakes up every first period to determine the presence or absence of a first fire event in the battery module, and wakes up every second period that is longer than the first period by a predetermined period when the battery module is determined to be in a stable state according to a predetermined safety standard, and determines the presence or absence of the first fire event; A master BMS that enters a sleep mode after transmitting a first control signal instructing entry into the first low-power mode to the slave BMS while the battery module is not supplying power to an external device; A battery system including the same.

2. The slave BMS compares battery data including information on the state of the battery module with a predetermined reference value to determine the presence or absence of the first fire event. The battery system according to claim 1.

3. The slave BMS determines that the battery module is in a stable state if the first fire event does not occur during a period when the total number of wake-ups according to the first period reaches a predetermined reference number of times. The battery system according to claim 1.

4. The master BMS wakes up when the first fire event occurs and determines the presence or absence of a second fire event according to a predetermined algorithm. The battery system according to claim 1.

5. The master BMS transmits a warning message corresponding to the occurrence of a fire in the battery module to a higher-level controller when the second fire event occurs. The battery system according to claim 4.

6. The master BMS If the second fire event does not occur, after transmitting a second control signal for instructing entry into the first low-power mode to the slave BMS, enter the sleep mode. The battery system according to claim 4.

7. A method for predicting the occurrence of a fire in a battery module, comprising: A stage in which a slave BMS that manages the battery module enters a sleep mode; A first low-power mode stage in which the slave BMS wakes up every first period to determine whether a first fire event has occurred in the battery module; When the battery module is determined to be in a stable state according to a predetermined safety standard, a second low-power mode stage in which the slave BMS wakes up every second period that is longer than the first period by a predetermined period to determine whether the first fire event has occurred A method for predicting a fire in a battery including the above.

8. The first low-power mode stage includes: A stage of determining that the state of the battery module is a stable state if the first fire event does not occur during a period when the total number of wake-ups according to the first period reaches a predetermined reference number of times. The method for predicting a fire in a battery according to claim 7.

9. Each of the first low-power mode stage and the second low-power mode stage includes: A stage in which the slave BMS compares battery data including information on the state of the battery module with a predetermined reference value to determine whether the first fire event has occurred. The method for predicting a fire in a battery according to claim 7.

10. Each of the first low-power mode stage and the second low-power mode stage includes: When the first fire event occurs, a master BMS that controls the slave BMS wakes up and further includes a stage of determining whether a second fire event has occurred according to a predetermined algorithm. The method for predicting a fire in a battery according to claim 9.

11. Each of the first low power mode stage and the second low power mode stage The method for predicting a fire in a battery according to claim 10, further comprising a step in which, when the second fire event occurs, the master BMS transmits a warning message corresponding to the occurrence of a fire in the battery module to a higher-level controller.

12. The second low power mode stage The method for predicting a fire in a battery according to claim 10, further comprising a step in which, if the second fire event does not occur, after the master BMS transmits a second control signal for instructing entry into the first low power mode to the slave BMS, the slave BMS enters the sleep mode.

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