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 the contents disclosed in the literature of the Korean patent application are included as part of this specification.

[0003] The present invention relates to a method for predicting the occurrence of a battery fire and a battery system that provides 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 instantly catching fire, and if the rescue time is delayed, the human life damage can increase significantly. 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 thermal runaway phenomenon of the battery in advance. A method that collects battery data such as the temperature and voltage of the battery and analyzes the changes in the collected battery data to predict the thermal runaway phenomenon of the battery 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 thermal runaway of the battery in advance. That is, the thermal runaway phenomenon of the battery 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 even when the battery is being charged with power from an external charger, or when the higher-level system (e.g., an automobile, an energy storage system, etc.) on which the battery is installed is not in operation, and the Battery Management System (BMS) is in sleep mode. [Means for solving the problem]

[0008] A battery system according to one feature of the present invention includes a battery module containing a plurality of battery cells; a slave BMS (Battery Management System) that wakes up every first cycle to determine whether or not a first fire event has occurred in the battery module, and when the battery module is determined to be in a stable state according to predetermined safety criteria, wakes up every second cycle which is a predetermined period longer than the first cycle to determine whether or not the first fire event has occurred; and a master BMS that, when the battery module is not supplying power to an external device, transmits a first control signal to the slave BMS instructing it to enter the first low-power mode, and then enters sleep mode.

[0009] The slave BMS can determine whether or not the first fire event has occurred by comparing battery data, which includes information about the state of the battery module, with a predetermined reference value.

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

[0011] When the first fire event occurs, the master BMS can wake up and determine whether or not a second fire event has occurred using a predetermined algorithm.

[0012] When the second fire event occurs, the master BMS can transmit a warning message corresponding to the fire in the battery module to the 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 to the slave BMS instructing it to enter the first low-power mode.

[0014] A battery fire prediction method according to another feature of the present invention is a method for predicting the occurrence of a fire in a battery module, comprising: a step in which a slave BMS (Slave Battery Management System) that manages the battery module enters sleep mode; a first low-power mode step in which the slave BMS wakes up every first cycle to determine whether or not a first fire event of the battery module has occurred; and a second low-power mode step in which, when the battery module is determined to be in a stable state according to predetermined safety criteria, the slave BMS wakes up every second cycle that is a predetermined period longer than the first cycle to determine whether or not the first fire event has occurred.

[0015] The first low-power mode stage may include a step in which the state of the battery module is determined to be stable if the first fire event does not occur during the period in which the total number of wake-ups in the first cycle reaches a predetermined reference number.

[0016] Each of the first low-power mode stage and the second low-power mode stage may include a step in which the slave BMS compares battery data, which includes information about the state of the battery module, with a predetermined reference value to determine whether or not the first fire event has occurred.

[0017] Each of the first low-power mode stage and the second low-power mode stage may further include a step in which, when the first fire event occurs, the master battery management system (MMS) that controls the slave BMS wakes up and determines whether or not a second fire event has occurred using a predetermined algorithm.

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

[0019] The second low-power mode stage may further include a step in which, if the second fire event does not occur, the master BMS transmits a second control signal to the slave BMS instructing it to enter the first low-power mode, and then enters the sleep mode. [Effects of the Invention]

[0020] An embodiment of the present invention can predict battery fires and reduce loss of life and property damage, even when the battery management system (BMS) is in sleep mode.

[0021] In embodiments of the present invention, power consumption of the battery management system (BMS) can be reduced by adjusting the wake-up period of the slave BMS to a short or long period depending on the safety status of the battery. [Brief explanation of the drawing]

[0022] [Figure 1] This is a block diagram illustrating a battery system according to one embodiment. [Figure 2] This is a block diagram illustrating the slave BMS and master BMS in detail. [Figure 3] This is a flowchart illustrating a method for predicting battery fires according to one embodiment. [Figure 4] It is a flowchart for explaining in detail the first low power mode stage S200 and the second low power mode stage S300 in FIG. 3.

Embodiments for Carrying Out the Invention

[0023] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the attached drawings. However, the same or similar components are assigned 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 there may be other components in between. 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 there are no other components in between.

[0026] In this application, terms such as “includes” or “having” are intended to specify the presence of features, figures, stages, actions, components, parts, or combinations thereof as described in the specification, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more other features, figures, stages, actions, components, parts, or combinations thereof.

[0027] Figure 1 is a block diagram illustrating a battery system according to one embodiment.

[0028] Referring to Figure 1, the battery system 1 includes a battery 10, a relay 20, and a battery management system (BMS) 30.

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

[0030] Battery 10 may include at least one battery module B. Battery module B may include multiple battery cells electrically connected in series and / or parallel. Figure 1 shows, but is not limited to, multiple battery modules B_1, B_2, ..., B_n, and battery 10 may include one battery module B_1. Also, Figure 1 shows, but is not limited to, multiple battery cells included in battery module B being connected in series, and can be connected in series and / or parallel. In one embodiment, the battery cells may be rechargeable secondary batteries.

[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 is discharged by supplying power to an external device. The charge state may be a state in which the battery 10 is charged by receiving power from an external device. The idle state may be a state in which the battery 10 and the external device are electrically connected, but no power is being transmitted. In this case, the external device may be a charger in the charge state and a load in the discharge state.

[0032] When the battery 10 is discharged, the battery management system (BMS) 30 can operate in an operating mode, managing the battery system 1 according to a pre-configured logic. When the battery 10 is charged or in a dormant state, the battery management system (BMS) 30 can operate in a sleep mode, not performing any pre-configured logic. Conventionally, when the battery 10 was charged or in a dormant state, the battery management system (BMS) 30 was in a sleep mode, not performing any operations, including predicting fire events for the battery 10. As a result, even if a fire occurred in the battery 10, such as a thermal runaway, while the battery 10 was charged or in a dormant state, no preparation was made in advance.

[0033] In this embodiment, the battery management system (BMS) 30 can operate in low-power mode when the battery 10 is charged or in a dormant state. The low-power mode is a mode in which the battery management system (BMS) 30, which was in sleep mode, wakes up every first cycle of a short-term cycle or every second cycle of a long-term cycle depending on the safety status of the battery, in order to predict a fire event in the battery 10.

[0034] Relay 20 electrically connects or disconnects the battery system 1 from the 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 occurs. 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] A slave BMS (P_BMS) can monitor and manage battery module B. The slave BMS (P_BMS) can be electrically connected to each of the multiple battery cells via wiring to collect battery data. This battery data may include at least one of the cell voltage, cell current, and cell temperature of each of the multiple battery cells, indicating the state of battery module B. The battery data may also include at least one of the module voltage (voltage across battery module B), module current (current flowing through battery module B), and module temperature (temperature of battery module B). In one embodiment, battery module B and the slave BMS (P_BMS) may constitute a single battery pack. The battery management system (BMS) 30 may include multiple slave BMSs (P_BMS) corresponding to each of the multiple battery modules B.

[0037] The master BMS (R_BMS) communicates with the controller of the higher-level system on which the battery system 1 is installed (hereinafter referred to as the higher-level controller) to send and receive various information, and can manage the battery management system (BMS) 30 overall.

[0038] In this embodiment, when the battery 10 is charged or in a sleep state, the slave BMS (P_BMS) may be operated in a first low-power mode or a second low-power mode under the control of the master BMS (R_BMS), and the master BMS (R_BMS) may be operated in sleep mode.

[0039] The first low-power mode or the second low-power mode is a mode in which the slave BMS (P_BMS), which was in sleep mode, wakes up every short-term first cycle or long-term second cycle depending on the battery's stability state to determine whether or not a first fire event has occurred in battery 10. In sleep mode, the master BMS (R_BMS) sleeps without performing any pre-configured logic unless it receives an alarm message from the slave BMS (P_BMS) corresponding to the occurrence of a first fire event.

[0040] Referring to Figure 1, each of the multiple slave BMSs (P_BMS_1, P_BMS_1, ..., P_BMS_n) that were in sleep mode can wake up every first or second cycle to collect battery data, compare the collected battery data with a first reference value, and determine whether or not a first fire event has occurred. When at least one of the multiple slave BMSs (P_BMS_1, P_BMS_1, ..., P_BMS_n) transmits an alarm message corresponding to the occurrence of a first fire event to the master BMS (R_BMS), the master BMS (R_BMS), which was in sleep mode, can wake up.

[0041] Figure 2 is a block diagram that provides a detailed explanation of the slave BMS and master BMS shown in Figure 1.

[0042] Referring to Figure 2, in one embodiment, each of the multiple 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. In another embodiment, in order to reduce the size of the battery management system (BMS) 30, each of the multiple slave BMSs (P_BMS_1, P_BMS_2, ..., P_BMS_n) can omit the control unit 315 and include only a monitoring unit 311 and a communication unit 313. In this case, each of the multiple slave BMSs (P_BMS_1, P_BMS_2, ..., P_BMS_n) can be operated under the control of a master BMS (R_BMS).

[0043] In the following, when specifying a particular slave BMS (P_BMS_1, P_BMS_2, ..., P_BMS_n) from among multiple slave BMSs, the drawing symbol "P_BMS_k" is used. Similarly, when specifying a particular battery module (B_1, B_2, ..., B_n) from among multiple battery modules, the drawing symbol "B_k" is used.

[0044] The monitoring unit 311 is electrically connected to each of the multiple battery cells included in the battery module B_k via wiring, and can 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 control the slave BMS (P_BMS_k) in general. For example, the control unit 315 may be composed of an MCU (microcontroller unit).

[0046] In one embodiment, the slave BMS (P_BMS_k) includes a control unit 315, and the slave BMS (P_BMS_k) wakes up every first 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 a first reference value to determine whether or not a first fire event has occurred.

[0047] In other embodiments where the slave BMS (P_BMS_k) does not include the control unit 315, the monitoring unit 311 can wake up every first or second cycle to collect battery data, compare the collected battery data with a first reference value, and determine whether or not a first fire event has occurred.

[0048] The communication unit 313 can communicate with the master BMS (R_BMS) via wired or wireless means. In this embodiment, the communication unit 313 can transmit battery data and alarm messages corresponding to the occurrence of a first fire event to the master BMS (R_BMS). Figures 1 and 2 show the communication method between the communication unit 313 and the master BMS (R_BMS) as CAN communication using a CAN bus, but are not limited to this, and communication modules providing various forms of wired or wireless communication methods can be included.

[0049] The master BMS (R_BMS) may 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 multiple slave BMSs (P_BMS_1, P_BMS_2, ..., P_BMS_n) via wired or wireless connection. For example, the master communication unit 331 may be composed of a communication bridge IC or the like.

[0051] In this embodiment, the master communication unit 331 can wake up the master control unit 335 when it receives an alarm message from at least one slave BMS (P_BMS_k). For example, the master communication unit 331 can wake up the master control unit 335 via the 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 one that can precisely predict a thermal runaway or the like a predetermined time before it occurs. The master storage unit 333 can also store battery data received from the slave BMS (P_BMS_k).

[0053] The master control unit 335 controls the battery system 1 overall. For example, the master control unit 335 may be composed of an MCU (microcontroller unit) or the like. When an alarm message is received via the master communication unit 331, the master control unit 335 wakes up and can determine whether or not a second fire event has occurred using a predetermined algorithm.

[0054] In this embodiment, in sleep mode, the slave BMS (P_BMS_k) wakes up at predetermined intervals to determine whether a first fire event has occurred by a simple method of comparing battery data with a reference value. If a first fire event occurs, the master BMS (R_BMS) wakes up to determine whether a second fire event has occurred by a precise algorithm.

[0055] The experimental results showed that in one 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 cycle (e.g., 1 second) to predict whether or not a first fire event will occur, the monitoring unit 311 consumes 80 μA / 1 sec of power, and the communication unit 313 consumes 12 μA / 1 sec of power. Furthermore, when the slave BMS (P_BMS_k) wakes up in the second cycle (e.g., 32 seconds) to predict whether or not a first fire event will occur, the monitoring unit 311 consumes 12 μA / 32 sec of power, and the communication unit 313 consumes 1 μA / 32 sec of power. Power consumption can be further reduced by adjusting the wake-up cycle according to the state of the battery 10, compared to when the slave BMS (P_BMS_k) wakes up at a fixed cycle.

[0056] Figure 3 is a flowchart illustrating a battery fire prediction method according to one embodiment, and Figure 4 is a flowchart illustrating in detail the first low-power mode stage S200 and the second low-power mode stage S300 of Figure 3.

[0057] First, referring to Figure 3, the master BMS (R_BMS) decides to enter low-power mode for the battery management system (BMS) 30 (S100).

[0058] The master BMS (R_BMS) may receive information from the electric vehicle's controller (hereinafter referred to as the higher-level controller) regarding whether the electric vehicle is in an operating state, running using the power of the battery 10; in a charging state, connected to an external charger; or in a parked state, with the electric vehicle's operation interrupted. Based on the information received from the higher-level controller, the master BMS (R_BMS) can control the battery management system (BMS) 30 in operating mode or low power mode. While this is described using an electric vehicle as an example of a higher-level system, it is not limited to this, and the following description is applicable to all kinds of higher-level systems on which the battery system 1 is installed.

[0059] [Table 1]

[0060] Table 1 above is an example illustrating the modes executed by the battery management system (BMS) 30 depending on the state of the electric vehicle and the battery 10.

[0061] For example, as shown in Table 1, in an operating state where the electric vehicle uses power from battery 10, battery 10 may also be in a discharge state where it supplies power to the electric vehicle. In this case, the battery management system (BMS) 30 can operate in an operating mode where it manages the battery system 1 using pre-configured logic. The pre-configured logic may include monitoring of battery 10, cell balancing of battery 10, prediction of battery 10 fire events, and switching control of relay 20.

[0062] As another example, as shown in Table 1, the battery management system (BMS) 30 can operate in low power mode in both the charge state, when the electric vehicle is charging the battery 10 with power from an external charger (not shown), and the parking state, when the battery 10 is not being used.

[0063] Sleep mode may be a mode in which no power is consumed and no pre-configured logic is performed. Low power mode may be a mode in which the device wakes up from sleep mode at predetermined intervals and consumes a predetermined amount of power to predict the occurrence of a fire event, based on pre-configured logic.

[0064] Specifically, in the low-power mode of the battery management system (BMS) 30, the slave BMS (P_BMS_k) may operate in either the first low-power mode or the second low-power mode, while the master BMS (R_BMS) may operate in 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), which was in sleep mode, wakes up at predetermined intervals (first or second cycle) to determine whether or not a first fire event has occurred in battery 10. Sleep mode is a mode in which the master BMS (R_BMS) sleeps without performing any pre-configured logic. However, if the master BMS (R_BMS) in sleep mode receives an alarm message from the slave BMS (P_BMS_k) corresponding to the occurrence of a first fire event, the master BMS (R_BMS) can wake up and determine whether or not a second fire event has occurred.

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

[0067] In this embodiment, when the battery 10 is in a charging state or a dormant state in which the battery 10 does not supply power to an external device, the master BMS (R_BMS) can transmit a first control signal to the slave BMS (P_BMS_k) that instructs it to enter a first low-power mode.

[0068] The first low-power mode may be a mode in which the slave BMS (P_BMS_k), which was in sleep mode, wakes up at the beginning of each short-term cycle to determine whether or not a first fire event has occurred in the battery 10. For example, the first cycle may be pre-set and stored in the slave BMS (P_BMS_k). As another example, the first cycle may be transmitted from the master BMS (R_BMS) to the slave BMS (P_BMS_k) at the S100 stage.

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

[0070] For example, the master BMS (R_BMS) can enter sleep mode after transmitting the first control signal to the slave BMS (P_BMS_k). In the first low-power mode, the slave BMS (P_BMS_k) maintains sleep mode until the first cycle arrives. At this time, the first cycle can be determined experimentally as the optimal cycle that reduces the power consumption of the slave BMS (P_BMS_k) while improving the precision of predicting the battery 10 ignition event.

[0071] At stage S200, when the first cycle arrives, the slave BMS (P_BMS_k) wakes up and determines whether or not the first fire event has occurred (S220).

[0072] The slave BMS (P_BMS_k) can collect battery data after wake-up. This battery data may include at least one of the following, indicating the state of each of the multiple battery cells: cell voltage, cell current, and cell temperature. The battery data may also include at least one of the following: module voltage (voltage across battery module B), module current (current flowing through battery module B), and module temperature (temperature of battery module B).

[0073] In this embodiment, the slave BMS (P_BMS_k) can compare battery data with a first reference value to determine whether or not a first fire event has occurred.

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

[0075] If the first fire event occurs at stage S200 (S230, Yes), the master BMS (R_BMS) wakes up and determines whether or not a second fire event will occur (S240).

[0076] In this 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) which is in sleep mode. In addition, the slave BMS (P_BMS_k) can transmit battery data to the master BMS (R_BMS) along with the alarm message.

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

[0078] In this embodiment, the master BMS (R_BMS) can determine whether or not a second fire event has occurred using a predetermined algorithm. The method for determining the occurrence of the first fire event may be simple but have low prediction accuracy. The method for determining the occurrence of the second fire event may be complex but have high prediction accuracy. In the low-power mode according to this 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 can determine the occurrence of a second fire event to improve the accuracy of predicting fire in the battery 10. At this time, the algorithm is not limited to a specific method and can include a variety of previously known methods that can predict fire in the battery 10.

[0079] If a second fire event occurs at stage S200 (S250, Yes), the master BMS (R_BMS) transmits a warning message to the higher-level controller (S260).

[0080] For example, the master BMS (R_BMS) can continue transmitting warning messages to the higher-level controller until it receives a response message to the warning message from the higher-level controller. At this time, the warning message may include data and justifications based on the prediction of a fire occurring in the battery 10.

[0081] If, at stage S200, 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 battery 10 according to the predetermined safety standards (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 battery 10 based on safety standards. In this case, the master BMS (R_BMS) may remain in sleep mode.

[0083] As another example, if a second fire event does not occur (S250, No), the master BMS (R_BMS) can transmit the result of the second fire event determination to the slave BMS (P_BMS_k). The slave BMS (P_BMS_k) can then determine the stability of battery 10 according to safety standards. However, this is not the only way; the master BMS (R_BMS) can also determine the stability of battery 10 according to safety standards.

[0084] The safety criteria may include predetermined conditions that allow for the determination that the state of battery 10 is stable. For example, the safety criteria may include a condition that no first fire event occurs during the 20 wake-up cycles of the first cycle, working backward from the time of determination. However, the safety criteria are not limited to this, and may include a variety of conditions that allow for the determination that the state of battery 10 is stable.

[0085] If the safety standards are not met at stage S200 (S270, No), the slave BMS (P_BMS_k) can be repeated from stage S210.

[0086] In the above explanation, the entity that determines whether or not safety standards are met was described as the slave BMS (P_BMS_k), but it is not limited to this; the master BMS (R_BMS) can also determine whether or not safety standards are met.

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

[0088] The second low-power mode may be a mode in which the slave BMS (P_BMS_k), which was in sleep mode, wakes up every second cycle of a long-term cycle to determine whether or not a first fire event has occurred in the battery 10. For example, the second cycle may be pre-set 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) along with a sleep command at the S100 stage.

[0089] For example, the second cycle can be set to a predetermined multiple of the first cycle, but is not limited to this. Experimental results showed that when the slave BMS (P_BMS_k) wakes up every 1 second to predict whether or not a fire event has occurred, the monitoring unit 311 consumes 80 μA / 1 sec of power, and the communication unit 313 consumes 12 μA / 1 sec of power. Also, when the slave BMS (P_BMS_k) wakes up every 32 seconds to predict whether or not a fire event has occurred, the monitoring unit 311 consumes 12 μA / 32 sec of power, and the communication unit 313 consumes 1 μA / 32 sec of power (however, power consumption may vary depending on the various settings of the battery system). When the slave BMS (P_BMS_k) wakes up at a fixed interval, rather than at a fixed interval, waking up at a short or long interval depending on the stable state of the battery 10 ensures the safety of the battery 10 while simultaneously reducing power consumption.

[0090] At stage S300, the slave BMS (P_BMS_k) and master BMS (R_BMS) first enter 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. The slave BMS (P_BMS_k) will then maintain sleep mode until the second cycle arrives. The master BMS (R_BMS) can then enter sleep mode on its own.

[0092] As another example, a slave BMS (P_BMS_k) can enter sleep mode on its own after deciding to enter the second low-power mode. The slave BMS (P_BMS_k) will then maintain sleep mode until the second cycle arrives. The master BMS (R_BMS), which was in sleep mode, can then continue to maintain sleep mode.

[0093] At stage S300, when the second cycle begins, the slave BMS (P_BMS_k) wakes up and determines whether or not the first fire event has occurred (S320).

[0094] The slave BMS (P_BMS_k) can collect battery data after wake-up. This battery data may include at least one of the following for each of the multiple battery cells: cell voltage, cell current, and cell temperature. The battery data may also include at least one of the following: module voltage (voltage across battery module B), module current (current flowing through battery module B), and module temperature (temperature of battery module B).

[0095] In this embodiment, the slave BMS (P_BMS_k) can compare battery data with a first reference value to determine whether or not a first fire event has occurred. For example, if at least two of the cell voltages corresponding to each of the multiple battery cells exceed the first reference value (e.g., 5V), the slave BMS (P_BMS) can determine that a first fire event has occurred. Furthermore, the explanation regarding the S220 stage described above is also applicable to the S320 stage.

[0096] If no first fire event occurs at stage S300 (S330, No), the slave BMS (P_BMS_k) can repeat from stage S310.

[0097] If the first fire event occurs at stage S300 (S330, Yes), the master BMS (R_BMS) wakes up and determines whether or not a second fire event has occurred (S340).

[0098] In this 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) which is in sleep mode. In addition, the slave BMS (P_BMS_k) can transmit battery data to the master BMS (R_BMS) along with the alarm message.

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

[0100] In this embodiment, the master BMS (R_BMS) can determine whether or not a second fire event has occurred using a predetermined algorithm. The content described in step S240 is also applicable to step S340.

[0101] If a second fire event occurs at stage S300 (S350, Yes), the master BMS (R_BMS) transmits a warning message to the higher-level controller (S360).

[0102] For example, the master BMS (R_BMS) can continue transmitting warning messages to the higher-level controller until it receives a response message to the warning message from the higher-level controller. At this time, the warning message may include data and justifications based on the prediction of a fire occurring in the battery 10.

[0103] If no second fire event occurs at stage S300 (S350, No), the master BMS (R_BMS) can control the slave BMS (P_BMS_k) to proceed to stage S200.

[0104] If no second fire event occurs, the master BMS (R_BMS) can transmit a second control signal to the slave BMS (P_BMS_k) instructing it to enter the first low-power mode. Then, at step S210, the master BMS (R_BMS) can enter sleep mode on its own.

[0105] Even if a second fire event does not occur, since a first fire event has occurred, the slave BMS (P_BMS_k) can wake up in the first period of the short cycle to determine whether or not a first fire event has occurred, in order to ensure the stability of battery 10.

[0106] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modified and improved forms by persons with ordinary skill in the art to which the present invention belongs also fall within the scope of the present invention.

Claims

1. A battery module containing multiple battery cells, A slave BMS that wakes up at the beginning of each first cycle to determine whether or not a first fire event has occurred in the battery module, and when the battery module is determined to be in a stable state according to predetermined safety criteria, wakes up at the beginning of each second cycle which is a predetermined period longer than the first cycle to determine whether or not a first fire event has occurred, With the battery module not supplying power to an external device, the master BMS transmits a first control signal to the slave BMS instructing it to enter the first low-power mode, and then enters sleep mode. A battery system, including a battery system.

2. The aforementioned slave BMS is The battery system according to claim 1, which determines whether or not the first fire event has occurred by comparing battery data, which includes information regarding the state of the battery module, with a predetermined reference value.

3. The aforementioned slave BMS is The battery system according to claim 1, wherein if the first fire event does not occur during the period in which the total number of wake-ups in the first cycle reaches a predetermined reference number, the battery module is determined to be in a stable state.

4. The aforementioned master BMS is The battery system according to claim 1, wherein when the first fire event occurs, it wakes up and determines whether or not a second fire event has occurred using a predetermined algorithm.

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

6. The aforementioned master BMS is The battery system according to claim 4, wherein if the second fire event does not occur, a second control signal instructing the slave BMS to enter the first low-power mode is transmitted, and then the system enters the sleep mode.

7. A method for predicting the occurrence of a fire in a battery module, The step in which the slave BMS managing the aforementioned battery module enters sleep mode, The slave BMS wakes up at the beginning of each cycle to determine whether or not a first fire event has occurred in the battery module in a first low-power mode phase, When the battery module is determined to be in a stable state according to predetermined safety standards, the slave BMS wakes up every second cycle, which is a predetermined period longer than the first cycle, to determine whether or not the first fire event has occurred, in a second low-power mode phase. When the battery module is not supplying power to an external device, the master BMS that controls the slave BMS transmits a first control signal to the slave BMS instructing it to enter the first low-power mode, and then enters sleep mode. A method for predicting battery fires, including the method described above.

8. The first low-power mode stage is The battery fire prediction method according to claim 7, further comprising the step of determining the state of the battery module as stable if the first fire event does not occur during the period in which the total number of wake-ups in the first cycle reaches a predetermined reference number.

9. The first low-power mode stage and the second low-power mode stage are, The battery fire prediction method according to claim 7, further comprising the step of the slave BMS comparing battery data, which includes information regarding the state of the battery module, with a predetermined reference value to determine whether or not the first fire event has occurred.

10. A method for predicting the occurrence of a fire in a battery module, The step in which the slave BMS managing the aforementioned battery module enters sleep mode, The slave BMS wakes up at the beginning of each cycle to determine whether or not a first fire event has occurred in the battery module in a first low-power mode phase, When the battery module is determined to be in a stable state according to predetermined safety standards, the slave BMS wakes up every second cycle, which is a predetermined period longer than the first cycle, and enters a second low-power mode stage to determine whether or not the first fire event has occurred. Includes, The first low-power mode stage and the second low-power mode stage are, The slave BMS includes a step of comparing battery data, which includes information regarding the state of the battery module, with a predetermined reference value to determine whether or not the first fire event has occurred. The first low-power mode stage and the second low-power mode stage are, A battery fire prediction method further comprising the step of a master BMS that controls the slave BMS waking up when the first fire event occurs, and determining whether or not a second fire event has occurred using a predetermined algorithm.

11. The first low-power mode stage and the second low-power mode stage are, The battery fire prediction method according to claim 10, further comprising the step of the master BMS transmitting 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.

12. The second low-power mode stage is The battery fire prediction method according to claim 10, further comprising the step of entering the sleep mode after the master BMS transmits a second control signal to the slave BMS instructing it to enter the first low-power mode if the second fire event does not occur.

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