Battery fire prediction method and battery system providing the same

Abstract

The present invention relates to a method for predicting the occurrence of a battery fire and a battery system providing the same. The battery system of the present invention comprises: a battery module comprising a plurality of battery cells; from a battery management system (BMS), a first low-power mode for waking up every first period and determining whether a first fire event of the battery module has occurred and a second low-power mode for waking up every second period when it is determined that the battery module is in a steady state according to a predetermined safety criterion, waking up each second period and determining whether a first fire event has occurred, the second period being longer than the first period by a predetermined interval; and a master BMS that transmits a first control signal indicating to enter a first low power mode to the slave BMS when the battery module does not supply power to the external device, and then enters a sleep mode.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0098831 filed in the Korean Intellectual Property Office on August 8, 2022, the entire contents of which are incorporated herein by reference.

[0003] The invention relates to a battery fire prediction method and a battery system providing the battery fire prediction method. Background Art

[0004] Unlike internal combustion engine vehicles, when an electric vehicle catches fire, it is difficult to put out the fire until the electric vehicle is burned. In addition, unlike internal combustion engine vehicles, electric vehicles have the characteristic of instantaneous combustion, and if rescue time is delayed, the number of casualties may increase. This happens because of the "thermal runaway" phenomenon in which the battery temperature soars to more than 1000℃.

[0005] Research and development of early detection of battery thermal runaway is currently underway. Methods for early prediction of battery thermal runaway phenomena by collecting battery data such as battery temperature and voltage and analyzing changes in the collected battery data are widely used.

[0006] However, in the charging state where the battery is charged with an external power source, the battery management system (BMS) is in sleep mode or shutdown mode. Therefore, the BMS cannot collect battery data and cannot predict battery thermal runaway in advance. In other words, since the battery thermal runaway phenomenon is not detected in advance, battery-related fires mainly occur when the battery is being charged. Summary of the invention

[0007] Technical issues

[0008] The present disclosure attempts to provide a battery fire prediction method and a battery system that provides the method even when the battery is charged with power from an external charger and a battery management system (BMS) is in a sleep mode because a superior system (e.g., a car, an energy storage system, etc.) in which the battery is installed is not operating.

[0009] Technical Solution

[0010] According to an embodiment of the present invention, a battery system includes: a battery module, the battery module including a plurality of battery cells; a slave battery management system BMS, the slave BMS executing a first low power mode and a second low power mode, in which the slave BMS wakes up every first cycle to determine whether a first fire event occurs in the battery module, and in the second low power mode, 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 cycle to determine whether the first fire event occurs, the second cycle having a predetermined period longer than the first cycle; and a master BMS, the master BMS sends a first control signal to the slave BMS indicating entering the first low power mode when the battery module does not provide power to an external device, and then the master BMS enters a sleep mode.

[0011] The slave BMS may determine whether the first fire event occurs by comparing battery data including information on the state of the battery module with a predetermined reference value.

[0012] The slave BMS may determine that the battery module is in a stable state when the first fire event does not occur during a period in which a total number of wake-up times according to the first cycle reaches a predetermined reference number of times.

[0013] The master BMS may wake up when the first fire event occurs and determine whether a second fire event occurs according to a predetermined algorithm.

[0014] When the second fire event occurs, the master BMS may send a warning message corresponding to the fire occurring in the battery module to the superior controller.

[0015] The master BMS may transmit a second control signal instructing to enter the first low power mode to the slave BMS when the second fire event does not occur, and then the master BMS enters the sleep mode.

[0016] According to another embodiment of the present invention, a battery fire prediction method includes the following steps: a step of managing a slave battery management system (BMS) of the battery module to enter a sleep mode; a first low power mode step, in which the slave BMS wakes up every first cycle to determine whether a first fire event occurs in the battery module; and a second low power mode step, 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 cycle to determine whether the first fire event occurs, the second cycle having a predetermined period longer than the first cycle.

[0017] The first low power mode step may include a step of determining that the battery module is in a stable state when the first fire event does not occur during a period in which a total number of wake-up times according to the first cycle reaches a predetermined reference number of times.

[0018] The first low power mode step and the second low power mode step may include comparing, by the slave BMS, battery data including information on the state of the battery module with a predetermined reference value to determine whether the first fire event occurs.

[0019] The first low power mode step and the second low power mode step may further include: when the first fire event occurs, waking up a master battery management system (BMS) that controls the slave BMS to determine whether a second fire event occurs according to a predetermined algorithm.

[0020] The first low power mode step and the second low power mode step may further include: when the second fire event occurs, the master BMS sends a warning message corresponding to the fire occurring in the battery module to a superior controller.

[0021] The second low power mode step may further include: when the second fire event does not occur, the master BMS sends a second control signal instructing to enter the first low power mode to the slave BMS, and then the master BMS enters the sleep mode.

[0022] Beneficial Effects

[0023] According to the present invention, even if a battery management system (BMS) is in a sleep mode, it is possible to predict the occurrence of fire in a battery and reduce casualties and property losses.

[0024] According to the present invention, a wake-up period from a BMS is adjusted to a short period or a long period according to a safety state of a battery, thereby saving power consumption of a battery management system (BMS). BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a block diagram for describing a battery system according to an embodiment.

[0026] Figure 2 It is shown in detail Figure 1 Block diagram of slave BMS and master BMS.

[0027] Figure 3 is a flowchart illustrating a battery fire prediction method according to an embodiment.

[0028] Figure 4 It is shown in detail Figure 3Flowchart of a first low power mode step (S200) and a second low power mode step (S300). DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar components are given the same reference numerals and are not described repeatedly. The suffixes "module" and / or "unit" of the components used in the following description are given or mixed only for the convenience of writing the specification, and therefore, they themselves do not have meanings or functions that distinguish each other. In addition, when it is determined that the detailed description of the known technology related to the present invention may obscure the main points of the present invention, the detailed description will be omitted. In addition, it should be understood that the drawings are provided only to make the embodiments of the present invention easy to understand, and the spirit of the present invention is not limited by the drawings, but includes all modifications, equivalents and substitutions included in the spirit and scope of the present invention.

[0030] Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components are not limited by the terms. These terms are only used to distinguish one component from another.

[0031] Furthermore, in this specification, it should be understood that when it is stated that one component is “connected” or “coupled” to another component, the one component may be directly connected or coupled to the other component, or connected to the other component with other components interposed therebetween. On the other hand, it should be understood that when it is stated that one element is “directly connected to” or “directly coupled to” another element, the one element may be connected or coupled to the other element without other elements interposed therebetween.

[0032] It should be further understood that the terms "include" or "have" used in this specification indicate the existence of the features, numbers, steps, operations, components, parts or a combination thereof mentioned in this specification, but do not exclude the existence or addition of one or more other features, numbers, steps, operations, components, parts or a combination thereof.

[0033] Figure 1 is a block diagram for describing a battery system according to an embodiment.

[0034] Reference Figure 1 , the battery system 1 includes a battery 10 , a relay 20 and a battery management system (BMS) 30 .

[0035] Reference Figure 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. Figure 1 The connection relationship between the configurations shown is an example, but the present invention is not limited thereto.

[0036] The battery 10 may include at least one battery module B. The battery module B may include a plurality of battery cells electrically connected in series and / or in parallel. Figure 1 A plurality of battery modules B_1, B_2, ... B_n are shown, but are not limited thereto, and the battery 10 may include one battery module B_1. Figure 1 It is shown that the plurality of battery cells included in the battery module B are connected in series, but the present invention is not limited thereto, and the plurality of battery cells may be connected in series and / or in parallel. In some embodiments, the battery cells may be rechargeable secondary batteries.

[0037] The battery 10 may be in a discharging state, a charging state, or an idle state. The discharging state may be a state in which the battery 10 supplies power to an external device to be discharged. The charging state may be a state in which the battery 10 is charged by receiving a power source from an external device. The idle state may be a state in which the battery 10 is electrically connected to an external device but does not transmit power. In this case, the external device may be a charger in a charging state and a load in a discharging state.

[0038] When the battery 10 is discharged, the battery management system (BMS) 30 may operate in an operation mode for managing the battery system 1 according to a preset logic. In the charging state and idle state of the battery 10, the battery management system (BMS) 30 may operate in a sleep mode in which the preset logic is not executed. Generally, in the charging state and idle state of the battery 10, the battery management system (BMS) 30 is in a sleep mode in which no operation including prediction of a fire event of the battery 10 is performed. Therefore, even if a fire such as thermal runaway occurs in the battery 10 in the charging state and idle state of the battery 10, it is impossible to prepare in advance.

[0039] According to an embodiment, the battery management system (BMS) 30 can operate in a low power mode when the battery 10 is in a charging state and an idle state. The low power mode is a mode in which the battery management system (BMS) 30 wakes up every first cycle (the first cycle is a short cycle) or second cycle (the second cycle is a long cycle) in a sleep mode according to the safety state of the battery, and predicts a fire event of the battery 10.

[0040] The relay 20 electrically connects or disconnects the battery system 1 and the external device under the control of the battery management system 30. When the relay 20 is turned on, the battery system 1 is electrically connected to the external device to perform charging or discharging. When the relay 20 is turned off, the battery system 1 is electrically disconnected from the external device.

[0041] The battery management system (BMS) 30 includes a slave BMS P_BMS and a master BMS R_BMS.

[0042] The slave BMS P_BMS may monitor and manage the battery module B. The slave BMS P_BMS may be electrically connected to each of the plurality of battery cells through a wire to collect battery data. In this case, the battery data may include at least one of a cell voltage, a cell current, and a cell temperature of each of the plurality of battery cells indicating the state of the battery module B. In addition, the battery data may include at least one of a module voltage, a module current, and a module temperature, wherein the module voltage is the voltage on the battery module B, the module current is the current flowing through the battery module B, and the module temperature is the temperature of the battery module B. In one embodiment, the battery module B and the slave BMS P_BMS may be configured as a battery pack. The battery management system (BMS) 30 may include a plurality of slave BMS P_BMS corresponding to each of the plurality of battery modules B.

[0043] The main BMS R_BMS may communicate with a controller of an upper system (hereinafter referred to as an upper controller) on which the battery system 1 is installed, transmit / receive various information, and manage the battery management system (BMS) 30 as a whole.

[0044] According to an embodiment, in the charging state and the idle state of the battery 10 , under the control of the master BMS R_BMS, the slave BMS P_BMS may operate in the first low power mode or the second low power mode, and the master BMS R_BMS may operate in the sleep mode.

[0045] The first low power mode or the second low power mode is a mode in which the slave BMS P_BMS wakes up every first cycle (the first cycle is a short cycle) or second cycle (the second cycle is a long cycle) in the sleep mode according to the stable state of the battery to determine whether the first fire event occurs. The sleep mode is a mode in which the master BMS R_BMS sleeps without executing a preset logic unless the master BMS R_BMS receives a warning message corresponding to the occurrence of the first fire event from the slave BMS P_BMS.

[0046] Reference Figure 1 , each of the plurality of slave BMSs P_BMS_1, P_BMS_2, ..., P_BMS_n may wake up in a sleep mode every first cycle or a second cycle to collect battery data, and compare the collected battery data with a first reference value to determine whether a first fire event occurs. When at least one of the plurality of slave BMSs P_BMS_1, P_BMS_2, ..., P_BMS_n sends a warning 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 may wake up.

[0047] Figure 2 It is shown in detail Figure 1 Block diagram of slave BMS and master BMS.

[0048] Reference Figure 2 According to one embodiment, each of the plurality of slave BMSs P_BMS_1, P_BMS_1, ..., P_BMS_n may 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_1, ..., P_BMS_n does not include the control unit 315 but may include the monitoring unit 311 and the communication unit 313. In this case, each of the plurality of slave BMSs P_BMS_1, P_BMS_1, ..., P_BMS_n may operate under the control of the master BMS R_BMS.

[0049] Hereinafter, reference numeral “P_BMS_k” is used to denote a specific slave BMS among a plurality of slave BMSs P_BMS_1, P_BMS_2, ..., P_BMS_n. Also, reference numeral “B_k” is used to denote a specific battery module among a plurality of battery modules B_1, B_2, ..., B_n.

[0050] The monitoring unit 311 may be electrically connected to each of the plurality of battery cells included in the battery module B_k through a wire to collect battery data. For example, the monitoring unit 311 may include a battery management IC (BMIC), an application specific IC (ASIC), and the like.

[0051] The control unit 315 may control the slave BMS P_BMS_k as a whole. For example, the control unit 315 may be configured as a microcontroller unit (MCU) or the like.

[0052] In one embodiment where the slave BMS P_BMS_k includes a 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 sends the battery data to the control unit 315. The control unit 315 may compare the battery data with a first reference value to determine whether a first fire event occurs.

[0053] In another embodiment where the slave BMS P_BMS_k does not include the control unit 315 , the monitoring unit 311 may wake up every first cycle or second cycle to collect battery data, and determine whether the first fire event occurs by comparing the collected battery data with a first reference value.

[0054] The communication unit 313 may communicate with the main BMS R_BMS in a wired or wireless manner. According to an embodiment, the communication unit 313 may send battery data and a warning message corresponding to the occurrence of the first fire event to the main BMS R_BMS. Figure 1 and Figure 2 , a communication method between the communication unit 313 and the main BMS R_BMS is illustrated as CAN communication using a CAN bus, but is not limited thereto, and may include a communication module providing various types of wired communication methods or wireless communication methods.

[0055] The master BMS R_BMS may include a master communication unit 331 , a master storage unit 333 , and a master control unit 335 .

[0056] The master communication unit 331 may communicate with the plurality of slave BMSs P_BMS_1, P_BMS_2, ..., P_BMS_n in a wired or wireless manner. For example, the master communication unit 331 may be configured as a communication bridge IC (IC) or the like.

[0057] According to an embodiment, the master communication unit 331 may wake up the master control unit 335 upon receiving a warning message from at least one slave BMS P_BMS_k. For example, the master communication unit 331 may wake up the master control unit 335 through an interrupt (INTR) line.

[0058] The main storage unit 333 may store at least one algorithm for predicting the occurrence of fire in the battery 10. For example, the algorithm may be an algorithm that can accurately predict a predetermined time before the occurrence of thermal runaway, etc. In addition, the main storage unit 333 may store battery data received from the slave BMS P_BMS_k.

[0059] The main control unit 335 controls the battery system 1 as a whole. For example, the main control unit 335 may be configured as a microcontroller unit (MCU), etc. Upon receiving a warning message through the main communication unit 331, the main control unit 335 may wake up and determine whether a second fire event occurs according to a predetermined algorithm.

[0060] According to one embodiment, in the sleep mode, the slave BMS P_BMS_k wakes up every predetermined period to determine whether the first fire event occurs by a simple method of comparing battery data and a reference value. When the first fire event occurs, the master BMS R_BMS wakes up to determine whether the second fire event occurs in an accurate method according to an algorithm.

[0061] 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 BMSP_BMS_k wakes up at a first cycle (e.g., 1 second) to predict whether the first fire event occurs, the monitoring unit 311 consumes 80 μA / 1 second of power, and the communication unit 313 consumes 12 μA / 1 second of power. In addition, when the slave BMS P_BMS_k wakes up at a second cycle (e.g., 32 seconds) to predict whether the first fire event occurs, the monitoring unit 311 consumes 12 μA / 32 seconds of power, and the communication unit 313 consumes 1 μA / 32 seconds of power. Compared with when the slave BMS P_BMS_k wakes up at a fixed cycle, when the wake-up cycle is adjusted according to the state of the battery 10, power consumption can be further reduced.

[0062] Figure 3 is a flowchart illustrating a battery fire prediction method according to an embodiment. Figure 4 It is shown in detail Figure 3 Flowchart of a first low power mode step (S200) and a second low power mode step (S300).

[0063] First, refer to Figure 3 , the main BMS R_BMS determines to enter a low power mode of the battery management system (BMS) 30 ( S100 ).

[0064] The main BMS R_BMS may receive information from a controller of the electric vehicle (hereinafter referred to as an upper controller) about whether the electric vehicle is in a running state in which the electric vehicle is operated using the power of the battery 10, in a charging state in which the electric vehicle is connected to an external charger, or in a parking state in which the operation of the electric vehicle is stopped. The main BMS R_BMS may control the battery management system (BMS) 30 to be in an operating mode or a low power mode based on the information sent from the upper controller. An electric vehicle is described as an example of an upper system, but is not limited thereto, and the following description may be applied to various types of upper systems in which the battery system 1 is installed.

[0065] [Table 1]

[0066]

[0067] Table 1 is an example for describing modes executed in a battery management system (BMS) 30 according to the states of the electric vehicle and the battery 10 .

[0068] For example, referring to Table 1, in an operating state where the electric vehicle uses the power of the battery 10, the battery 10 may be in a discharging state to provide power to the electric vehicle. In this case, the battery management system (BMS) 30 may operate in an operating mode to manage 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 an ignition event of the battery 10, switch control of the relay 20, and the like.

[0069] As another example, referring to Table 1, the battery management system (BMS) 30 may operate in a low power mode in a charging state in which the battery 10 of the electric vehicle is charged using power from an external charger (not shown) and in a parking state in which power of the battery 10 is not used, respectively.

[0070] The sleep mode may be a mode in which power is not used because a preset logic is not executed. The low power mode is a mode in which a fire event is predicted during a preset logic by waking up from the sleep mode at a predetermined cycle and may consume a predetermined power.

[0071] Specifically, in the low power mode of the battery management system (BMS) 30 , the slave BMS P_BMS_k may operate in the first low power mode or the second low power mode, and the master BMS R_BMS may operate in the sleep mode.

[0072] In the first low power mode or the second low power mode, the slave BMS P_BMS_k in the sleep mode wakes up every predetermined cycle (first cycle or second cycle) to determine whether the first fire event occurs in the battery 10. The sleep mode is a mode in which the master BMS R_BMS sleeps without executing a preset logic. However, when the master BMS R_BMS in the sleep mode receives a warning message corresponding to the occurrence of the first fire event from the slave BMS P_BMS_k, the master BMS R_BMS wakes up to determine whether the second fire event occurs.

[0073] 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 performs the first low power mode ( S200 ).

[0074] According to an embodiment, in a charging state or an idle state of the battery 10 in which the battery 10 does not provide power to an external device, the master BMS R_BMS may transmit a first control signal instructing entry into a first low power mode to the slave BMS P_BMS_k.

[0075] 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 cycle (the first cycle is a short cycle) to determine whether a first fire event occurs in the battery 10. For example, the first cycle may be preset and stored in the slave BMS P_BMS_k. As another example, the first cycle may be transmitted from the master BMSR_BMS to the slave BMS P_BMS_k in step S100.

[0076] Reference Figure 4 , in step S200 , first, the slave BMS P_BMS_k and the master BMS R_BMS enter a sleep mode ( S210 ).

[0077] For example, the master BMS R_BMS may enter the sleep mode by itself after sending the first control signal to the slave BMS P_BMS_k. In the first low power mode, the slave BMS P_BMS_k maintains the sleep mode until the first cycle arrives. In this case, the first cycle may be determined through experiments as an optimal cycle capable of improving the prediction accuracy of the ignition event of the battery 10 while reducing the power consumption of the slave BMS P_BMS_k.

[0078] In step S200 , when the first cycle arrives, the slave BMS P_BMS_k wakes up to determine whether a first fire event occurs ( S220 ).

[0079] The slave BMS P_BMS_k may collect battery data after waking up. In this case, the battery data may include at least one of a cell voltage, a cell current, and a cell temperature indicating a state of each of a plurality of battery cells. In addition, the battery data may include at least one of a module voltage, a module current, and a module temperature, the module voltage being the voltage on the battery module B, the module current being the current flowing through the battery module B, and the module temperature being the temperature of the battery module B.

[0080] According to an embodiment, the slave BMS P_BMS_k may determine whether the first fire event occurs by comparing battery data with a first reference value.

[0081] For example, when at least two cell voltages among a plurality of cell voltages corresponding to each of a plurality of battery cells exceed a first reference value (e.g., 5V), the slave BMS P_BMS_k may determine that a first fire event occurs in the battery module B. As another example, when a temperature of the battery module B exceeds a second reference value (e.g., 30° C.), the slave BMS P_BMS may determine that a first fire event occurs in the battery module B. However, it is not limited thereto, and the slave BMS P_BMS_k may determine whether the first fire event occurs in various ways by comparing the size of the battery data and the first reference value.

[0082] In step S200 , when the first fire event occurs ( S230 , Yes), the main BMS R_BMS wakes up to determine whether the second fire event occurs ( S240 ).

[0083] According to an embodiment, when the first fire event occurs, the slave BMS P_BMS_k may send a warning message to the master BMS R_BMS. The warning message may serve as a trigger to wake up the master BMS R_BMS in sleep mode. In addition, the slave BMS P_BMS_k may send battery data together with the warning message to the master BMS R_BMS.

[0084] The master communication unit 331 may wake up the master control unit 335 upon receiving a warning message from at least one slave BMS P_BMS_k. For example, the master communication unit 331 may wake up the master control unit 335 through an interrupt (INTR) line.

[0085] According to an embodiment, the main BMS R_BMS may determine whether the second fire event occurs according to a predetermined algorithm. The method for determining the occurrence of the first fire event may be a simple fire prediction method with low prediction accuracy. The method for determining the occurrence of the second fire event may be a fire prediction method with a more complex but high prediction accuracy. In a low power mode according to an embodiment, the battery management system (BMS) 30 periodically determines the occurrence of the first fire event to reduce power consumption, and determines the occurrence of the second fire event when the first fire event occurs, thereby improving the accuracy of predicting the occurrence of a fire in the battery 10. In this case, the algorithm is not limited to a specific method, and may include various known methods capable of predicting the occurrence of a fire in the battery 10.

[0086] In step S200 , when the second fire event occurs ( S250 , Yes), the main BMS R_BMS transmits a warning message to the superior controller ( S260 ).

[0087] For example, the main BMS R_BMS may continue to send a warning message to the superior controller until a response message to the warning message is received from the superior controller. In this case, the warning information may include data based on a prediction of a fire occurring in the battery 10, a basis for judgment, and the like.

[0088] In operation S200 , when the first fire event does not occur ( S230 , No) or 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 ).

[0089] For example, when the first fire event does not occur (S230, No), the slave BMS P_BMS_k may determine the stability of the battery 10 according to the safety standard. In this case, the master BMS R_BMS may continue to be in the sleep mode.

[0090] As another example, when the second fire event does not occur (S250, No), the master BMS R_BMS may transmit the second fire event determination result to the slave BMS P_BMS_k. Then, the slave BMS P_BMS_k may determine the stability of the battery 10 according to the safety standard. However, it is not limited thereto, and the master BMS R_BMS may determine the stability of the battery 10 according to the safety standard.

[0091] The safety standard may include a predetermined condition for determining that the state of the battery 10 is stable. For example, the safety standard may include a condition that the first fire event will not occur when the wake-up cycle according to the first cycle is repeated 20 times based on the determined time point retroactively. However, it is not limited thereto, and the safety standard may include various conditions for determining that the state of the battery 10 is stable.

[0092] In step S200 , when the stability criterion is not satisfied ( S270 , No), the slave BMS P_BMS_k may be repeatedly executed starting from step S210 .

[0093] In the above, the slave BMS P_BMS_k has been described as a subject for determining whether the stability criterion is satisfied, but is not limited thereto, and the master BMS R_BMS may also determine whether the stability criterion is satisfied.

[0094] Next, when the stability criterion is satisfied ( S270 , YES), the second low power mode is performed by the slave BMS P_BMS_k ( S300 ).

[0095] 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 cycle (the second cycle is a long 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 sent from the master BMS R_BMS to the slave BMS P_BMS_k together with the sleep instruction in step S100.

[0096] For example, the second cycle can be set to a predetermined multiple of the first cycle, but is not limited thereto. As a result of the experiment, when waking up from the BMS P_BMS_k every second and predicting whether a fire event occurs, the monitoring unit 311 consumes 80 μA / 1 second of power, and the communication unit 313 consumes 12 μA / 1 second of power. In addition, when waking up from the BMS P_BMS_k every 32 seconds to predict whether a fire event occurs, the monitoring unit 311 consumes 12 μA / 32 seconds of power, and the communication unit 313 consumes 1 μA / 32 seconds of power (however, the power consumption may vary according to various setting values ​​of the battery system). Compared with waking up from the BMS P_BMS_k at a fixed cycle, when waking up from the BMS P_BMS_k at a short cycle or a long cycle according to the stable state of the battery 10, the power consumption can be reduced while ensuring the safety of the battery 10.

[0097] In step S300 , first, the slave BMS P_BMS_k and the master BMS R_BMS enter a sleep mode ( S310 ).

[0098] For example, the master BMS R_BMS may command 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 cycle arrives. The master BMS R_BMS may enter the sleep mode by itself.

[0099] As another example, the slave BMS P_BMS_k may enter the sleep mode by itself after determining to enter the second low power mode. Then, the slave BMS P_BMS_k maintains the sleep mode until the second cycle arrives. The master BMS R_BMS in the sleep mode may continue to maintain the sleep mode.

[0100] In step S300 , when the second cycle arrives, the slave BMS P_BMS_k wakes up to determine whether a first fire event occurs ( S320 ).

[0101] Battery data may be collected after waking up from the BMS P_BMS_k. In this case, the battery data may include at least one of a cell voltage, a cell current, and a cell temperature of each of the plurality of battery cells. In addition, the battery data may include at least one of a module voltage, a module current, and a module temperature, wherein the module voltage is the voltage on the battery module B, the module current is the current flowing through the battery module B, and the module temperature is the temperature of the battery module B.

[0102] According to an embodiment, the slave BMS P_BMS_k may determine whether the first fire event occurs by comparing the battery data with the first reference value. For example, when at least two of the plurality of cell voltages corresponding to each of the plurality of battery cells exceed the first reference value (e.g., 5V), the slave BMS P_BMS may determine that the first fire event occurs. In addition, the description of step S220 above may also apply to step S320.

[0103] In step S300 , when the first fire event does not occur ( S330 , No), the slave BMS P_BMS_k may repeat the step S310 .

[0104] In step S300 , when the first fire event occurs ( S330 , Yes), the main BMS R_BMS wakes up to determine whether the second fire event occurs ( S340 ).

[0105] According to an embodiment, when the first fire event has occurred, the slave BMS P_BMS_k may send a warning message to the master BMS R_BMS. The warning message may serve as a trigger for waking up the master BMS R_BMS in sleep mode. In addition, the slave BMS P_BMS_k may send battery data together with the warning message to the master BMS R_BMS.

[0106] The master communication unit 331 may wake up the master control unit 335 upon receiving a warning message from at least one slave BMS P_BMS_k. For example, the master communication unit 331 may wake up the master control unit 335 through an interrupt (INTR) line.

[0107] According to an embodiment, the main BMS R_BMS may determine whether the second fire event occurs according to a predetermined algorithm. The contents described in step S240 may also be applicable to step S340.

[0108] In step S300 , when the second fire event occurs ( S350 , Yes), the main BMS R_BMS sends a warning message to the superior controller ( S360 ).

[0109] For example, the main BMS R_BMS may continue to send a warning message to the superior controller until a response message to the warning message is received from the superior controller. In this case, the warning information may include data based on a prediction of a fire occurring in the battery 10, a basis for judgment, and the like.

[0110] In step S300 , when the second fire event does not occur ( S350 , No), the master BMS R_BMS may control the slave BMS P_BMS_k to perform step S200 .

[0111] When the second fire event does not occur, the master BMS R_BMS may transmit a second control signal instructing to enter the first low power mode to the slave BMS P_BMS_k. Then, in step S210, the master BMS R_BMS may enter the sleep mode by itself.

[0112] Even if the second fire event does not occur, since the first fire event occurs, for the stability of the battery 10 , the slave BMS P_BMS_k wakes up at a first cycle (the first cycle is a short cycle) to determine whether the first fire event occurs.

[0113] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by a person of ordinary skill in the art to which the present invention pertains belong to the scope of the present invention.

Claims

1. A battery system, comprising: A battery module, wherein the battery module comprises a plurality of battery cells, A slave battery management system (BMS), wherein the slave BMS executes a first low power mode and a second low power mode, wherein in the first low power mode, the slave BMS wakes up every first cycle to determine whether a first fire event occurs in the battery module, and in the second low power mode, 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 cycle to determine whether the first fire event occurs, and the second cycle has a predetermined period longer than the first cycle; as well as a master BMS which transmits a first control signal instructing to enter the first low power mode to the slave BMS in a state in which the battery module does not supply power to an external device, and then the master BMS enters a sleep mode.

2. The battery system according to claim 1, wherein: Said from BMS: Whether the first fire event occurs is determined by comparing battery data including information on the state of the battery module with a predetermined reference value.

3. The battery system according to claim 1, wherein: Said from BMS: When the first fire event does not occur during a period in which the total number of wake-up times according to the first cycle reaches a predetermined reference number, it is determined that the battery module is in a stable state.

4. The battery system according to claim 1, wherein: The main BMS: When the first fire event occurs, the system wakes up and determines whether a second fire event occurs according to a predetermined algorithm.

5. The battery system according to claim 4, wherein: The main BMS: When the second fire event occurs, a warning message corresponding to the fire occurring in the battery module is sent to a superior controller.

6. The battery system according to claim 4, wherein: The main BMS: When the second fire event does not occur, a second control signal instructing to enter the first low power mode is sent to the slave BMS and then enters the sleep mode.

7. A battery fire prediction method, the battery fire prediction method comprising the following steps: Steps for entering sleep mode from a battery management system (BMS) that manages the battery module; a first low power mode step, in which the slave BMS is awakened every first cycle to determine whether a first fire event occurs in the battery module; as well as A second low power mode step, 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 cycle to determine whether the first fire event occurs, and the second cycle has a predetermined period longer than the first cycle.

8. The battery fire prediction method according to claim 7, wherein: The first low power mode step comprises: When the first fire event does not occur during a period in which the total number of wake-up times according to the first cycle reaches a predetermined reference number, determining that the battery module is in a stable state.

9. The battery fire prediction method according to claim 7, wherein: The first low power mode step and the second low power mode step include: Battery data including information on the state of the battery module is compared with a predetermined reference value by the slave BMS to determine whether the first fire event occurs.

10. The battery fire prediction method according to claim 9, wherein: The first low power mode step and the second low power mode step further include: When the first fire event occurs, a master battery management system (BMS) that controls the slave BMS is awakened to determine whether a second fire event occurs according to a predetermined algorithm.

11. The battery fire prediction method according to claim 10, wherein: The first low power mode step and the second low power mode step further include: When the second fire event occurs, the master BMS sends a warning message corresponding to the fire in the battery module to the superior controller.

12. The battery fire prediction method according to claim 10, wherein: The second low power mode step further comprises: When the second fire event does not occur, a second control signal instructing to enter the first low power mode is transmitted by the master BMS to the slave BMS and then the master BMS enters the sleep mode.

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