Battery Monitoring System

Abstract

To provide a battery monitoring system capable monitoring presence / absence of abnormality while leveling power consumption of battery modules as much as possible.SOLUTION: A battery monitoring system 1 comprises a plurality of monitoring circuits 41 to 43, a microcomputer 10, and a communication bridge 20. The plurality of monitoring circuits 41 to 43 are connected in series through insulation communication paths 50, respectively, and use power of battery modules 36 to 38 in charge that are assigned to the monitoring circuits to acquire data on the battery modules. The communication bridge 20 uses a power supply differing from the battery modules 36 to 38 to start from a low power consumption mode autonomously from the microcomputer 10, and instructs the monitoring circuits 41 to 43 to acquire data on a battery 35 to acquire the data using communication. The communication bridge 20 determines whether or not a state of the battery 35 is abnormal on the basis of the acquired data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a battery monitoring system. [Background technology]

[0002] For example, vehicles such as electric vehicles (EVs) are equipped with assembled batteries, such as lithium-ion batteries, for propelling the vehicle. The assembled batteries are configured by combining battery modules, and generally, a monitoring monitor equipped with a monitoring circuit monitors the state of each battery module, and the monitoring circuit determines whether or not there is an abnormality in the battery state (see, for example, Patent Document 1).

[0003] According to conventional technology, when the circuit configuration of a battery monitoring system is operating in low power consumption mode, the top monitoring circuit of the monitoring circuits connected insulated to the microcontroller in a ring shape functions as the master while the microcontroller is asleep. The master monitoring circuit then wakes up one of the slave monitoring circuits. The woken-up monitoring circuit then monitors whether or not there is an abnormality in the battery module and transmits the result to the next slave monitoring circuit. The multiple monitoring circuits repeat this wake-up and monitoring sequence in order to determine whether or not there is an abnormality in each battery module.

[0004] With this technology, when the circuit configuration of the battery monitoring system is operating in low power consumption mode, an arbitrary monitoring circuit is designated as the master, and other monitoring ICs become slaves. Because the master must wake up when a specified time has elapsed, it must perform a count-up operation during sleep. This increases the current consumption for the count-up operation.

[0005] On the other hand, since the slave side does not need to count up, the master and slave operate differently, resulting in differences in current consumption for each monitored battery stack. This increases the power consumption of the master monitoring circuit. Although it is required that the power consumption of battery modules be equalized, it is not possible to equalize the power consumption of battery modules. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 1,134,0975 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present disclosure is to provide a battery monitoring system that can monitor the presence or absence of abnormalities while leveling out the power consumption of battery modules as much as possible. [Means for solving the problem]

[0008] The battery monitoring system described in claim 1 comprises multiple monitoring circuits, a microcomputer, and a communication bridge. The multiple monitoring circuits are connected in series via a communication path and acquire data related to the battery module assigned to them using the power of the battery module. The microcomputer normally instructs the multiple monitoring circuits to monitor the battery and monitors the battery status. The communication bridge is a circuit connected to at least one of the multiple monitoring circuits via a communication path and instructs the acquisition of data. When the microcomputer is in sleep mode, it switches to a low-power consumption mode that consumes less power than normal.

[0009] The communication bridge uses a power source separate from the battery module and starts up from a low-power consumption mode autonomously from the microcomputer, instructs the monitoring circuit to acquire battery-related data, and acquires data from multiple monitoring circuits via communication.The communication bridge then determines whether the battery status is abnormal based on the acquired data.

[0010] Therefore, the monitoring circuit starts up from low power consumption mode and acquires data, but does not determine whether there is an abnormality in the battery; it only detects it. When the communication bridge starts up from low power consumption mode, it acquires data from multiple monitoring circuits via communication and determines whether there is an abnormality in the battery state.

[0011] The communication bridge determines whether an abnormality exists based on data obtained from multiple monitoring circuits, making it possible to determine abnormalities without starting up the microcontroller. This allows the startup time of each monitoring circuit, which consumes power from the battery module, to be leveled out, minimizing variations in the current consumption of the battery module. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is an electrical configuration diagram illustrating a battery monitoring system according to a first embodiment. [Figure 2] FIG. 1 is an electrical diagram showing the internal configuration of a communication bridge and a monitoring circuit. [Figure 3] Flowchart for explaining the operation [Figure 4] Normal signal transmission and reception sequence diagram [Figure 5] An explanatory diagram of the signal transmission and reception sequence in the event of an abnormality [Figure 6] Diagram of abnormality notification method 1 [Figure 7] Diagram of abnormality notification method 2 [Figure 8] Diagram 1 of how to read battery data [Figure 9] Diagram 2 of how to read battery data [Figure 10] FIG. 1 is an electrical configuration diagram illustrating the internal configuration of a communication bridge and a monitoring circuit according to a comparative example. [Figure 11] Configuration example 1 of communication connection mode showing the second embodiment [Figure 12] Communication connection configuration example 2 DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, several embodiments will be described with reference to the drawings. In some embodiments, the same or similar components are designated by the same or similar reference numerals, and the description thereof may be omitted.

[0014] (First embodiment) A first embodiment will be described below with reference to Figs. 1 to 10. The battery monitoring system 1 includes a microcomputer 10, a communication bridge 20, a storage device 21, a battery 35, a plurality of monitoring circuits 41 to 43, and an insulated communication path 50. The battery 35 is also called a battery pack. The battery 35 is configured by connecting battery modules 36 to 38 in series. The battery modules 36 to 38 may also be connected in series-parallel. The battery modules 36 to 38 are also called a battery stack.

[0015] Monitoring circuits 41 to 43 are assigned to the battery modules 36 to 38 in advance, respectively, and the monitoring circuits 41 to 43 operate using the power of the battery modules 36 to 38. The monitoring circuits 41 to 43 acquire data related to the battery modules 36 to 38 to which they are assigned.

[0016] Insulated communication paths 50 are respectively configured between the communication bridge 20 and the monitoring circuit 41, between the monitoring circuit 41 and the monitoring circuit 42, and between the monitoring circuit 42 and the monitoring circuit 43. For example, the communication bridge 20 and the monitoring circuits 41 to 43 are daisy-chain connected. This allows the communication bridge 20 and the multiple monitoring circuits 41 to 43 to communicate with each other insulated from each other.

[0017] The insulated communication path 50 is configured using capacitors C1 to C4 as insulating elements. Although the insulating elements are shown configured by the capacitors C1 to C4, transformers may be used instead of the capacitors C1 to C4. The communication bridge 20 is a circuit that converts the communication method between the microcomputer 10 and the multiple monitoring circuits 41 to 43. When the communication bridge 20 receives a data acquisition instruction from the microcomputer 10, it instructs the multiple monitoring circuits 41 to 43 to acquire the data.

[0018] The multiple monitoring circuits 41 to 43 are connected in series with each other. The monitoring circuits 41 to 43 are connected so as to be able to detect the voltages of the battery cells that make up each battery module 36 to 38. The monitoring circuits 41 to 43 are each assigned to a battery module 36 to 38 that they are to monitor.

[0019] Each of the multiple monitoring circuits 41 to 43 is mainly configured with a battery monitoring IC. Here, the monitoring circuits 41 to 43 are shown as being implemented as ICs, but this is not limited to this. Since the monitoring circuits 41 to 43 have the same configuration, the functional configuration of the monitoring circuit 41 will be described.

[0020] 2, the monitoring circuit 41 includes a battery data acquisition circuit 47 and communication I / Fs 48 and 49. The battery data acquisition circuit 47 acquires data (hereinafter referred to as battery data) related to a pre-assigned battery module 36 among the battery modules 36 to 38. The battery data indicates voltage data of each battery cell constituting the corresponding battery module 36 to 38, its positional information, identification information (ID information) of the monitoring circuits 41 to 43, information for determining the time of acquisition, detection data of gas released from the battery 35, etc. The communication I / Fs 48 and 49 of the monitoring circuit 41 are interfaces for communication with the other monitoring circuits 42 and 43 and the communication bridge 20, and each have a built-in communication buffer.

[0021] The monitoring circuits 41 to 43 have a function of detecting the voltage of each battery cell of the battery modules 36 to 38, an equalization function for equalizing the voltage of each battery cell of the battery modules 36 to 38, and a function of detecting the temperature of the battery modules 36 to 38. Each of the monitoring circuits 41 to 43 may have at least one of these functions.

[0022] <Microcomputer 10 function explanation> The microcomputer 10 operates by receiving power supply from a battery 4 (corresponding to a "power source": auxiliary battery) different from the battery 35 via a power supply circuit 5. During normal operation, the microcomputer 10 instructs a plurality of monitoring circuits 41-43 to acquire data related to the battery 35 via a communication bridge 20. During normal operation, the microcomputer 10 acquires data related to the battery 35 from the plurality of monitoring circuits 41-43, detects the current flowing through the battery 35, and estimates the SOC and SOH of the battery cells of the battery 35 based on the cell voltage and cell current.

[0023] SOH is an abbreviation for States Of Health, and is an index that indicates the deterioration state of the battery 35. SOC is an abbreviation for State Of Charge, and is an index that indicates the charge state of the battery 35. Furthermore, the microcomputer 10 can detect an abnormality in a battery cell by, for example, comparing the open circuit voltages of the individual battery cells of the battery 35 and determining whether or not they are within a certain range.

[0024] For example, when a higher-level ECU (not shown) detects that the ignition switch is turned off, it issues a command to the microcomputer 10, causing the microcomputer 10 to transition to sleep mode. When transitioning the microcomputer 10 to sleep mode, the operation of the power supply circuit 5 that supplies power to the microcomputer 10 may be shut down, or the microcomputer 10 may be instructed to transition to sleep mode. This reduces the power consumption of the microcomputer 10, thereby achieving low power consumption.

[0025] <Functional Description of Communication Bridge 20> The communication bridge 20 is connected in series and cascade to a plurality of monitoring circuits 41 to 43. The communication bridge 20 operates by receiving power from a battery 4 different from the battery 35. The communication bridge 20 is configured with a communication IC and is connected to a storage device 21. Here, the communication bridge 20 is shown as being implemented as an IC, but this is not limitative. As illustrated in FIG. 2, the communication bridge 20 includes an abnormality determination circuit 22 as a determination unit 20c, a monitoring circuit control unit 23, a battery data holding circuit 24, an abnormality determination threshold holding circuit 25, a timer 26, a communication method conversion unit 27, communication I / Fs 28 and 29, and an I / F 31.

[0026] The communication I / F 29 is a communication interface with the connected monitoring circuit 41, and performs data communication with the monitoring circuit 41 according to an insulated communication method. The communication I / F 28 is a communication interface with the connected microcomputer 10, and performs data communication with the microcomputer 10 according to a predetermined communication method.

[0027] The communication method conversion unit 27 represents a block that converts the communication method between the communication I / F 28 and the communication I / F 29. The communication method conversion unit 27 converts the communication method with the microcomputer 10 into a communication method suitable for insulated communication with the monitoring circuit 41. Conversely, the communication method conversion unit 27 converts the communication method suitable for insulated communication with the monitoring circuit 41 into a communication method suitable for communication with the microcomputer 10.

[0028] Timer 26 counts time when communication bridge 20 transitions to the low power consumption mode, and when a predetermined time has elapsed, outputs a monitor start signal to monitoring circuit control unit 23. When monitoring circuit control unit 23 receives the monitor start signal from timer 26, it outputs a start signal to monitoring circuits 41 to 43 via communication I / F 29, or outputs an instruction signal instructing them to acquire data.

[0029] The battery data holding circuit 24 is configured with a so-called buffer memory and holds battery data related to the battery 35 acquired from the monitoring circuits 41-43 via the communication I / F 29. Examples of the battery data include voltage data and position information of each battery cell constituting the battery modules 36-38, and identification information (ID information) of the monitoring circuits 41-43 from which the data was acquired. Other examples of the battery data include temperature data of the battery modules 36-38, the time at which the data was acquired, and detection data of gas released from the battery 35. The battery data holding circuit 24 writes the battery data to the storage device 21 in a non-volatile manner via the communication I / F 30.

[0030] The storage device 21 is configured by a nonvolatile memory IC such as an EEPROM. Although the storage device 21 is configured by an EEPROM, this is not limiting and any memory may be used as long as it has a nonvolatile memory.

[0031] The abnormality determination threshold holding circuit 25 holds a threshold for determining an abnormality, such as a threshold for the voltage of the battery cells or a threshold for the temperature of the battery modules 36 to 38. The abnormality determination circuit 22 compares the data held in the battery data holding circuit 24 with the threshold for determining an abnormality held by the abnormality determination threshold holding circuit 25 to determine whether an abnormality exists. For example, by comparing the data with the threshold for the voltage of each battery cell of the battery modules 36 to 38, the presence or absence of an abnormality is determined by determining whether the voltage falls within a predetermined range.

[0032] If the abnormality determination circuit 22 determines that an abnormality has occurred, it can notify the microcomputer 10 or the power supply circuit 5 of the abnormality via the I / F 31. The data that the communication bridge 20 transmits to the microcomputer 10 is time-series data based on the battery data stored in the storage device 21. Specifically, the data can include time-series data on the temperature of the battery modules 36 to 38, data on temperature changes over time based on voltage data of each battery cell, data on voltage changes of the battery cells, and time-series data on detection data of gas released from the battery 35.

[0033] The communication bridge 20 is configured as a block as shown in Fig. 2 above, but functionally, it can be described as having the functions of an instruction unit 20a, an acquisition unit 20b, and a determination unit 20c, as shown in Fig. 1. The instruction unit 20a has a function of starting up from a low power consumption mode autonomously from the microcomputer 10 and instructing the monitoring circuits 41 to 43 to acquire data related to the battery 35. The acquisition unit 20b has a function of acquiring data from the monitoring circuits 41 to 43 via communication. The determination unit 20c has a function of determining whether the state of the battery 35 is abnormal or not based on the acquired data.

[0034] The following describes the above-mentioned configuration, focusing on the operation of the microcomputer 10 while it is in sleep mode. As mentioned above, during normal operation, the microcomputer 10 acquires the status of the battery 35 and can monitor the status of the battery 35 in detail. When the microcomputer 10 goes into sleep mode to reduce power consumption, the communication bridge 20 and the multiple monitoring circuits 41-43 also enter a low power consumption mode, which consumes less power than normal. If the communication bridge 20 and the multiple monitoring circuits 41-43 also enter a low power consumption mode, the overall power consumption of the battery monitoring system 1 can be reduced, resulting in lower power consumption.

[0035] <Monitoring operation during normal operation while the microcomputer 10 is in sleep mode> The operations under normal conditions (FIG. 4) and abnormal conditions (FIG. 5) will be described along with the processing contents of the monitoring circuits 41 to 43 shown in FIG. 3. As shown in S101 of FIG. 4, in the low power consumption mode, the communication bridge 20 executes counting by the timer 26 and autonomously starts up when a predetermined time has elapsed (S1 of FIG. 3, S102 of FIGS. 4 and 5).

[0036] The communication bridge 20 transmits activation signals to the plurality of monitoring circuits 41 to 43 via the insulated communication path 50 to activate each of the monitoring circuits 41 to 43 in the low power consumption mode (S2 in FIG. 3, S103 in FIGS. 4 and 5).

[0037] The communication bridge 20 transmits a data acquisition command to the plurality of monitoring circuits 41 to 43 through the insulated communication path 50. The plurality of monitoring circuits 41 to 43 each receive the data acquisition command (S104 in FIGS. 4 and 5). The plurality of monitoring circuits 41 to 43 acquire battery data in response to the data acquisition command (S3 in FIG. 3, S105 in FIGS. 4 and 5).

[0038] Next, the communication bridge 20 transmits a data read command. The plurality of monitoring circuits 41 to 43 each receive the data read command (S106 in FIGS. 4 and 5). The plurality of monitoring circuits 41 to 43 transmit the battery data acquired in response to the data read command to the communication bridge 20 (S4 in FIG. 3, S107 in FIGS. 4 and 5). A specific example of a method for transmitting battery data will be described collectively in the second embodiment. The communication bridge 20 receives and acquires the battery data from the plurality of monitoring circuits 41 to 43 (S4 in FIG. 3). The communication bridge 20 stores the battery data in the battery data storage circuit 24.

[0039] Next, the communication bridge 20 transmits a command to transition to the low power consumption mode to the plurality of monitoring circuits 41 to 43. The plurality of monitoring circuits 41 to 43 each receive the low power consumption mode transition command (S108 in FIGS. 4 and 5). Then, the plurality of monitoring circuits 41 to 43 transition to the low power consumption mode (S109 in FIGS. 4 and 5).

[0040] The communication bridge 20 transmits the battery data to the storage device 21 to store it (S110 in FIG. 4, S110a in FIG. 5). The communication bridge 20 determines whether the battery data indicates an abnormality in the battery 35 (S5 in FIG. 3, S111 in FIG. 4, S111a in FIG. 5). Specifically, the abnormality determination circuit 22 of the communication bridge 20 compares the battery data held in the battery data holding circuit 24 with the threshold held in the abnormality determination threshold holding circuit 25 to determine whether the battery data exceeds the threshold.

[0041] If the abnormality determination circuit 22 of the communication bridge 20 determines that the battery 35 is normal and does not indicate an abnormality, the communication bridge 20 transitions to the low power consumption mode by itself (S7 in FIG. 3, S112 in FIG. 4).

[0042] Conversely, if the abnormality determination circuit 22 of the communication bridge 20 determines that the state of the battery 35 is abnormal, it activates the microcomputer 10 (S6 in FIG. 3 and S111a in FIG. 5). When the abnormality determination circuit 22 determines that the state of the battery 35 is abnormal, the communication bridge 20 transmits an activation signal to the power supply circuit 5 to activate the power supply circuit 5 that supplies power to the microcomputer 10, as shown in FIG. 6. The communication bridge 20 then activates the power supply circuit 5, thereby activating the microcomputer 10. At this time, the communication bridge 20 preferably transmits an abnormality notification trigger to the microcomputer 10 and the power supply circuit 5, thereby instructing the power supply circuit 5 to start supplying power to the microcomputer 10.

[0043] 7, when the abnormality determination circuit 22 determines that the state of the battery 35 is abnormal, the communication bridge 20 may send a start-up signal to the microcomputer 10 to start up the microcomputer 10, thereby starting up the microcomputer 10. At this time, the power supply circuit 5 may continue to supply power to the microcomputer 10.

[0044] Communication bridge 20 notifies microcomputer 10 that an abnormality has occurred in battery 35 (S8 in FIG. 3). When microcomputer 10 is notified that an abnormality has occurred in battery 35, it takes action based on the abnormality.

[0045] At this time, after waking up from sleep, the microcomputer 10 reads the data stored in the storage device 21 and uses it to determine the state (SOH, etc.) of the battery 35. Since the microcomputer 10 can obtain detailed battery data of the battery 35 from each of the monitoring circuits 41 to 43, it can determine in detail what kind of abnormality has occurred in the battery 35.

[0046] 9, the communication bridge 20 may write battery data to a storage device 21, and the microcomputer 10 may read the battery data written in the storage device 21. The storage device 21 is externally attached to the communication bridge 20. Therefore, even if the communication bridge 20 transitions to a low power consumption mode after writing the battery data to the storage device 21, the microcomputer 10 can easily refer to the storage device 21 external to the communication bridge 20. This allows the microcomputer 10 to use the storage device 21 for detailed measurements of the battery 35 (for example, SOH measurement). The storage device 21 may be built into the communication bridge 20.

[0047] <Summary of this embodiment> According to this embodiment, the communication bridge 20 starts up from the low power consumption mode autonomously from the microcomputer 10 and instructs the monitoring circuits 41 to 43 to acquire data related to the battery 35 (function of the instruction unit 20a). The communication bridge 20 acquires battery data from the multiple monitoring circuits 41 to 43 through communication (function of the acquisition unit 20b). Based on the read battery data, the communication bridge 20 determines whether the state of the battery 35 is abnormal using the abnormality determination circuit 22 (function of the determination unit 20c).

[0048] Therefore, the monitoring circuits 41-43 start up from the low power consumption mode and acquire data, but do not determine whether or not there is an abnormality in the battery modules 36-38 of the battery 35; they only detect the abnormality. When the communication bridge 20 starts up from the low power consumption mode using power from the battery 4, it acquires data from the multiple monitoring circuits 41-43 via communication and determines whether or not there is an abnormality in the state of the battery 35. Because the communication bridge 20 determines whether or not there is an abnormality based on the data acquired from the multiple monitoring circuits 41-43, it can determine an abnormality without starting up the microcomputer 10.

[0049] The communication bridge 20 functions as a master, and the monitoring circuits 41 to 43 function as slaves. This allows the startup times of the monitoring circuits 41 to 43, which consume the power of the battery modules 36 to 38, to be leveled, and the variations in the current consumption of the battery modules 36 to 38 to be minimized.

[0050] Furthermore, the communication bridge 20 can perform measurements autonomously without relying on the microcontroller 10, waking up the microcontroller 10 only when an abnormality occurs. The communication bridge 20 can collect battery data from all monitoring circuits 41-43, allowing for the understanding of overall battery data for the battery 35. In the technology described in Patent Document 1, the battery cells targeted for abnormality detection are limited to the battery cells monitored by the monitoring circuits and the battery cells closest to the monitoring circuits. However, in this embodiment, it is possible to detect abnormal temperature and voltage deviations for the entire battery 35. While only one communication bridge 20 is required per system, multiple monitoring circuits 41-43 are required. Therefore, in this embodiment, the number of memories per system can be reduced, contributing to cost reduction and miniaturization.

[0051] <Comparative Example> The configuration of the comparative example is shown in Figure 10. According to the configuration of this comparative example, the monitoring circuits 41 to 43 include the abnormality determination circuit 22, the abnormality determination threshold holding circuit 25, and the timer 26 described above. When the timer 26 measures the passage of a predetermined time in the low power consumption mode, the monitoring circuits 41 to 43 generate a monitoring start signal, and the battery data acquisition circuit 47 acquires voltage data (battery data) of each battery cell of the battery modules 36 to 38.

[0052] The abnormality determination circuit 22 then compares the acquired battery data with the threshold value of the abnormality determination threshold holding circuit 25 to determine whether or not an abnormality exists. If an abnormality exists, the multiple monitoring circuits 41 to 43 transmit the abnormality to the abnormality determination circuit 122 of the communication bridge 20 via the communication I / Fs 48 and 29. Meanwhile, the communication bridge 20 is activated in low power consumption mode by receiving an activation signal from the monitoring circuits 41 to 43. At this time, if the abnormality determination circuit 122 receives an abnormality notification from the monitoring circuits 41 to 43, it notifies the microcomputer 10. Furthermore, the communication bridge 20 measures a specified time using a watchdog timer 126, and if it does not receive a notification from the monitoring circuits 41 to 43 within this specified time, it determines that an abnormality has occurred in the insulated communication path 50 and notifies the microcomputer 10.

[0053] According to such a configuration, for example, when the plurality of monitoring circuits 41 to 43 are in a low power consumption mode, the plurality of monitoring circuits 41 to 43 are activated by the timers 26 individually provided for each of them, and if an abnormality occurs, each of them notifies the communication bridge 20 of the occurrence of the abnormality at the timing of activation.

[0054] If multiple monitoring circuits 41 to 43 simultaneously notify that an abnormality has occurred, multiple abnormality signals will be simultaneously present on one insulated communication path 50. In this case, an arbitration function is required to determine which monitoring circuit's abnormality signal should take priority, which undesirably complicates the communication protocol.

[0055] As another comparative example, if a method is adopted in which the monitoring circuits 41-43 are activated in sequence through communication between them and then the state of the battery 35 is detected, a time difference is likely to occur in the timing of monitoring the states of the battery modules 36-38. Because the battery modules 36-38 are configured with battery cells connected in series or in series-parallel, it is desirable to synchronize the monitoring timing of each battery module 36-38 as much as possible in order for the microcomputer 10 and the like to use battery cell voltage data to determine detailed SOH and the like.

[0056] According to this embodiment, the communication bridge 20 first activates the multiple monitoring circuits 41-43, and then transmits various commands for battery monitoring control. This eliminates the need for a separate arbitration function. Furthermore, it is possible to reduce the time difference between the voltage monitoring timings of the battery cells that make up the battery modules 36-38.

[0057] Furthermore, in the prior art, there were cases where battery data information was unavailable when the ignition switch was off. In such cases, the microcomputer 10 estimated the SOH based only on battery data information obtained while the vehicle was running. However, the degree of deterioration of the battery 35 also changes depending on the temperature environment and battery voltage while the vehicle is stopped. Therefore, if battery data information obtained while the vehicle is stopped is available, the microcomputer 10 can estimate the SOH with higher accuracy. In this embodiment, the battery data information obtained while the ignition switch is off is stored in the storage device 21, allowing the microcomputer 10 to estimate the SOH with higher accuracy.

[0058] (Second embodiment) The second embodiment will be described with reference to Figures 11 and 12. In the above-described embodiment, it has been described that when the monitoring circuits 41 to 43 receive a data read command, they transmit battery data to the communication bridge 20 in response to the command, but it is preferable that this transmission method be as shown in Figure 11 or 12.

[0059] A case will be described where the communication bridge 20 transmits a data read command to the monitoring circuits 41 to 43. The data read command can be received by the multiple monitoring circuits 41 to 43 in sequence via the above-mentioned communication I / Fs 48 and 49. For example, as shown in Fig. 11, if the communication bridge 20 and the multiple monitoring circuits 41 to 43 are connected in a ring shape by an insulated communication path 50, the monitoring circuits 41, 42, and 43 may pass battery data in sequence, and the communication bridge 20 may ultimately receive all of the battery data.

[0060] In this case, the monitoring circuit 41 first acquires battery data of the battery module 36 it is responsible for and transmits the battery data to the monitoring circuit 42 via the insulated communication path 50. Upon receiving the battery data from the monitoring circuit 41, the monitoring circuit 42 acquires battery data of the battery module 37 it is responsible for. The monitoring circuit 42 transmits the battery data of the battery modules 36, 37 to the monitoring circuit 43 via the insulated communication path 50.

[0061] When the monitoring circuit 43 receives the battery data from the monitoring circuit 42, it acquires the battery data of the battery module 38 it is responsible for and transmits the battery data of the battery modules 36-38 to the communication bridge 20 via the insulated communication path 50. This allows the communication bridge 20 to receive the battery data of all the battery modules 36-38.

[0062] For example, as shown by the arrows in Figure 12, if the communication bridge 20 and multiple monitoring circuits 41 to 43 are connected in series by an insulated communication path 50 and are not connected in a ring, communication may be performed in reverse.

[0063] For example, when the communication bridge 20 transmits a data read command to the monitoring circuits 41 to 43, the monitoring circuit 41 acquires battery data from the battery module 36 it is responsible for and transmits it to the monitoring circuit 42 via the insulated communication path 50. The monitoring circuit 42 acquires battery data from the battery module 37 it is responsible for and transmits the battery data of the battery modules 36, 37 to the monitoring circuit 43 via the insulated communication path 50. The monitoring circuit 43 acquires battery data from the battery module 38 it is responsible for and transmits the battery data of the battery modules 36 to 38 to the communication bridge 20 via the monitoring circuits 42, 41 via the insulated communication path 50. This allows the communication bridge 20 to acquire the battery data of all the battery modules 36 to 38.

[0064] Alternatively, the monitoring circuit 43 may first acquire battery data from the battery module 38 it is responsible for and transmit the data to the communication bridge 20 via the insulated communication path 50. The monitoring circuit 42 may then acquire battery data from the battery module 37 it is responsible for and transmit the battery data of the battery modules 38 and 37 to the communication bridge 20 via the insulated communication path 50.

[0065] The monitoring circuit 41 acquires battery data from the battery module 36 it is responsible for and transmits the battery data of the battery module 36 to the communication bridge 20 via the insulated communication path 50. This allows the communication bridge 20 to acquire the battery data of all battery modules 36 to 38. Either method allows the communication bridge 20 to acquire the battery data of all battery modules 36 to 38 that make up the battery 35. This provides the same effects as the above-described embodiment.

[0066] (Other embodiments) The present invention is not limited to the above-described embodiment, and the following modifications or extensions are possible. The techniques described in this disclosure may be implemented by a special purpose computer provided by configuring a processor and memory programmed to perform one or more functions embodied in a computer program, or alternatively, the techniques described in this disclosure may be implemented by a special purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits.

[0067] Alternatively, the techniques described in this disclosure may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with one or more hardware logic circuits, and the computer program may be stored on a computer-readable non-transitory storage medium as instructions for execution by the computer.

[0068] In addition to the claims, the present disclosure also includes the following inventions. [1] a communication bridge (20) connected to at least one of the plurality of monitoring circuits via the communication path and configured to transition to a low power consumption mode that consumes less power than normal when the microcomputer is in sleep mode, the communication bridge being configured to start up from the low power consumption mode autonomously from the microcomputer using a power source different from that of the battery modules; an instruction unit (20a) that instructs the acquisition of the data related to the battery; an acquisition unit (20b) that acquires the data from the plurality of monitoring circuits via communication; and a determination unit (20c) that determines whether the state of the battery is abnormal based on the acquired data.

[0069] [2] A battery monitoring system as described in [1], wherein the plurality of monitoring circuits transition to a low power consumption mode while the microcontroller is in the sleep mode, and the communication bridge activates the monitoring circuits in the low power consumption mode through the communication path.

[0070] [3] The battery monitoring system according to [1] or [2], wherein the communication bridge notifies the microcomputer of a start-up signal for starting the microcomputer when the judgment unit judges that the battery state is abnormal.

[0071] [4] The battery monitoring system according to any one of [1] to [3], wherein when the judgment unit judges that the battery state is abnormal, the communication bridge sends a start-up signal to the power supply circuit (5) that supplies power to the microcomputer to start the power supply circuit, and starts the microcomputer by starting the power supply circuit.

[0072] [5] A battery monitoring system according to any one of [1] to [4], wherein the communication bridge transitions to the low power consumption mode by itself when the judgment unit judges that the battery state is normal.

[0073] [6] The battery monitoring system according to any one of [1] to [5], wherein the communication bridge stores the acquired data in a memory (21).

[0074] [7] [6] The battery monitoring system according to [6], wherein after waking up from the sleep state, the microcomputer reads the data stored in the memory and uses the data to determine the state of the battery.

[0075] Although the present disclosure has been described based on the above-described embodiment, it is understood that the present disclosure is not limited to the embodiment or the structure described in the embodiment. The present disclosure also encompasses various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0076] In the drawing, 4 indicates a battery (power source), 5 indicates a power supply circuit, 10 indicates a microcomputer, 20a indicates an instruction unit, 20b indicates an acquisition unit, 20c indicates a judgment unit, 21 indicates a storage device (memory), 22 indicates an abnormality judgment circuit (judgment unit), 35 indicates a battery, 36 to 38 indicate battery modules, 41 to 43 indicate monitoring circuits, and 50 indicates an insulated communication path (communication path).

Claims

1. A battery monitoring system for monitoring a battery (35) having a plurality of battery modules, comprising: a plurality of monitoring circuits (41-43) connected in series via a communication path (50) and using the power of the battery modules (36-38) assigned to them to acquire data related to the battery modules; a microcomputer (10) that monitors the state of the battery during normal operation; a communication bridge (20) that is a circuit connected to at least one of the plurality of monitoring circuits via the communication path and is configured to transition to a low power consumption mode in which power consumption is lower than normal when the microcomputer is in sleep mode; the communication bridge is activated from the low power consumption mode autonomously from the microcomputer using a power source different from the battery module; an instruction unit (20a) that instructs acquisition of the data related to the battery; an acquisition unit (20b) that acquires the data from the plurality of monitoring circuits through communication; a determination unit (20c) that determines whether the state of the battery is abnormal based on the acquired data; A battery monitoring system comprising:

2. When the microcomputer is in the sleep state, the plurality of monitoring circuits are in a low power consumption mode, The battery monitoring system according to claim 1 , wherein the communication bridge activates the monitoring circuit in the low power consumption mode through the communication path.

3. 2. The battery monitoring system according to claim 1, wherein the communication bridge notifies the microcomputer of a start-up signal for starting the microcomputer when the determining unit determines that the state of the battery is abnormal.

4. The battery monitoring system of claim 1, wherein when the judgment unit judges that the battery state is abnormal, the communication bridge sends a start-up signal to the power supply circuit (5) that supplies power to the microcomputer to start the power supply circuit, and starts the microcomputer by starting the power supply circuit.

5. 2. The battery monitoring system according to claim 1, wherein the communication bridge automatically transitions to the low power consumption mode when the determining unit determines that the state of the battery is normal.

6. 2. The battery monitoring system according to claim 1, wherein the communication bridge stores the acquired data in a memory (21).

7. 7. The battery monitoring system according to claim 6, wherein after waking up from the sleep state, the microcomputer reads out the data stored in the memory and uses the data to determine the state of the battery.

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