Battery management system

Abstract

To provide a battery management system that suppresses increase in a memory capacity of a communication circuit that performs two-way communication with a plurality of monitoring circuits.SOLUTION: A battery management system comprises: n (n is a natural number of 2 or more) measurement circuits connected in series in a daisy chain, each measuring at least one of voltage or current of each of a plurality of batteries included in a battery pack, and transmitting measurement data with a specific data size including the measured information; a communication circuit that performs two-way communication with the n measurement circuits; and a battery manager for managing each of the plurality of batteries. The communication circuit includes i (i is a natural number of 2 or more) first-in first-out memories for temporarily storing the measurement data in first-in first-out order, stores the plurality of measurement data transmitted in time series order from m (m is a natural number of 2 or more) groups each includes 2 or more measurement circuits in the first-in first-out memories, and transmits the stored plurality of measurement data to the battery manager.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] The battery management system (BMS) disclosed in Patent Document 1 includes multiple monitoring circuits that monitor the voltages (cell voltages) of multiple batteries included in a battery pack, the currents (cell currents) flowing through the multiple batteries, etc. The BMS also includes a communication circuit that communicates with each of the multiple monitoring circuits, and a battery manager that manages the battery pack.

[0003] In a conventional BMS, multiple voltage detection monitoring circuits are connected to a communication circuit in a ring, or daisy chain, and perform unidirectional communication with the battery manager via the communication circuit over the ring line.On the other hand, current detection monitoring circuits are not daisy chain connected but are directly connected to the communication circuit and perform bidirectional communication with the battery manager.

[0004] Voltage measurement data measured by multiple voltage detection monitoring circuits is sent to the battery manager via one-way communication. In other words, the voltage measurement data is sent to the battery manager via one-way communication without being stored in a FIFO (First-In First Out) (passing through the communication circuit). Current measurement data measured by current detection monitoring circuits is temporarily stored in a FIFO within the communication circuit. In other words, the current measurement data is stored in the FIFO, and then the communication circuit sends it to the battery manager.

[0005] As described above, the conventional technology assumes that two or more specific monitoring circuits among a plurality of monitoring circuits communicate unidirectionally. In other words, the conventional technology does not consider a method for transmitting measurement data when two or more specific monitoring circuits among a plurality of monitoring circuits communicate bidirectionally with a communication circuit and a battery manager. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-076890 Summary of the Invention [Problem to be solved by the invention]

[0007] As a countermeasure to this problem, all measurement data including voltage measurement data may be temporarily stored in a FIFO so that two or more specific monitoring circuits can simultaneously transmit the measurement data to the battery manager.

[0008] However, in this case, the more monitoring circuits there are and the more data each monitoring circuit transmits, the larger the data size of the measurement data received by the communication circuit becomes. This increases the memory capacity of the FIFO in the communication circuit, and the increased memory capacity can increase the mounting area of ​​the battery management system. As such, the conventional technology leaves room for improvement in terms of temporarily storing measurement data in the memory of the communication circuit that communicates bidirectionally with multiple monitoring circuits.

[0009] In view of the above circumstances, the present disclosure aims to provide a battery management system that suppresses an increase in the memory capacity of a communication circuit that performs bidirectional communication with multiple monitoring circuits. [Means for solving the problem]

[0010] In order to solve the above problems, the battery management system of the present disclosure includes n (n is a natural number of 2 or more) measurement circuits connected in series in a daisy chain, each measuring at least one of the voltage and current of a plurality of batteries included in an assembled battery and transmitting measurement data of a specific data size including the measured information, a communication circuit that performs bidirectional communication with the n measurement circuits, and a battery manager that manages each of the plurality of batteries, wherein the communication circuit includes i (i is a natural number of 2 or more) first-in-first-out memories that temporarily store the measurement data in first-in, first-out order, and stores the plurality of measurement data transmitted in chronological order from m (m is a natural number of 2 or more) groups each including two or more of the measurement circuits in the first-in, first-out memories, and transmits the stored plurality of measurement data to the battery manager. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a configuration diagram of a battery management system 100 according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram showing an example of the configuration of the communication circuit 5. [Figure 3A] FIG. 3A is a diagram for explaining the operation of the battery management system 100 according to the embodiment of the present disclosure. [Figure 3B] FIG. 3B is a diagram for explaining the operation of the battery management system 100 according to the embodiment of the present disclosure. [Figure 3C] FIG. 3C is a diagram for explaining the operation of the battery management system 100 according to the embodiment of the present disclosure. [Figure 3D] FIG. 3D is a diagram for explaining the operation of the battery management system 100 according to the embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram for explaining the memory capacity of a communication circuit 5A according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be described with reference to the drawings. Note that the same or similar reference numerals are used to designate the same functions or configurations, and descriptions thereof will be omitted as appropriate.

[0013] (Embodiment) 1 is a configuration diagram of a battery management system 100 according to an embodiment of the present disclosure. The battery management system 100 may be interpreted as a circuit that monitors the voltage (cell voltage) of each of a plurality of batteries included in a battery pack 200, the current (cell current) flowing through each of the plurality of batteries, and the like. Each of the plurality of batteries may be interpreted as a battery cell, a battery stack including a plurality of battery cells therein, or a battery module including a plurality of battery stacks therein.

[0014] The battery management system 100 may include a communication system 10 , a battery manager 20 , and a network 30 .

[0015] (Network 30) The network 30 connects the battery manager 20 and the communication system 10. As an example, the network 30 may be a CAN (Controller Area Network).

[0016] (Communication System 10) The communication system 10 is communicatively connected to the battery manager 20 via a network 30. The communication system 10 may include a communication circuit 5 and a group of communication devices. The group of communication devices includes a plurality of communication devices, which may be interpreted as measurement circuits 1-1 to 1-11, measurement circuit 7, etc. The measurement circuits 1-1 to 1-11 and measurement circuit 7 may each be realized by a computer equipped with a processor. In the following, for simplicity of explanation, unless otherwise specified, the plurality of measurement circuits (measurement circuits 1-1 to 1-11 and measurement circuit 7) may be simply referred to as a plurality of measurement circuits 1.

[0017] (Communication circuit 5) The communication circuit 5 may be connected to the plurality of measurement circuits 1 in a loop by a serial communication line 6. The communication circuit 5 may perform bidirectional communication with each of the plurality of measurement circuits 1 via the serial communication line 6. The communication circuit 5 may perform bidirectional communication with the battery manager 20 via a network 30. The communication circuit 5 may be realized by a computer having a processor.

[0018] The serial communication line 6 may be interpreted as a first communication line for connecting multiple measurement circuits 1 (e.g., measurement circuits 1-1 to 1-11, measurement circuit 7) to the communication circuit 5 in a daisy chain, and for two-way communication between the multiple measurement circuits 1 and the communication circuit 5.

[0019] The network 30 may be interpreted as a second communication line that connects the communication circuit 5 to the battery manager 20 and enables bidirectional communication between the communication circuit 5 and the battery manager 20. The data communication speed of the second communication line is equal to or higher than the data communication speed of the first communication line.

[0020] For example, if the communication speed of the serial communication line 6 between each measuring circuit 1 and the communication circuit 5 is 1 Mbps and the number of writes (number of FIFO memories) is 3, the communication speed of the network 30 will be 3 Mbps (= 1 Mbps x 3) or more. However, it is desirable to set the communication speed of the network 30 to 4 Mbps or more with some margin.

[0021] The communication circuit 5 may include i (i is a natural number equal to or greater than 2) first-in-first-out memories that temporarily store measurement data in first-in-first-out order. FIG. 2 is a diagram showing an example configuration of the communication circuit 5. As shown in FIG. 2, the communication circuit 5 may include, for example, three first-in-first-out memories 51-1 to 51-3. Each of the first-in-first-out memories 51-1 to 51-3 may be considered as a FIFO memory. Hereinafter, the first-in-first-out memories 51-1 to 51-3 may be simply referred to as the first-in-first-out memory 51.

[0022] The communication circuit 5 may store multiple measurement data transmitted in chronological order from m groups (m is a natural number greater than or equal to 2) each including two or more measurement circuits, in, for example, three first-in, first-out memories 51, and transmit the stored multiple measurement data to the battery manager 20.

[0023] The number of first-in, first-out memories 51 may be interpreted as the number of n (n is a natural number greater than or equal to 2) measurement circuits 1 divided by the number of groups m, that is, 1 / m times (m is a natural number greater than or equal to 2).

[0024] The number of groups m and the number of first-out first-in memories 51 will be described below.

[0025] (When the number of groups m is 4) Among the measurement circuits 1-1 to 1-11 and the measurement circuit 7, group A may include measurement circuits 7, 1-1, and 1-11; group B may include measurement circuits 1-2, 1-3, and 1-10; group C may include measurement circuits 1-4, 1-5, and 1-9; and group D may include measurement circuits 1-6, 1-7, and 1-8. When the number of measurement circuits n is 12 and the number of groups m is 4, the number of FIFO memories 51 is three. FIG. 2 illustrates the total memory capacity required for the FIFO when the number of groups m is 4, the number of FIFO memories 51 is three, and the data amount per cell is 18 bits. In this case, the total memory capacity required for the FIFO is 108 bytes.

[0026] (When the number of groups m is 3) Among the measurement circuits 1-1 to 1-11 and the measurement circuit 7, group A may include measurement circuits 7, 1-1, 1-2, and 1-11, group B may include measurement circuits 1-3, 1-4, 1-5, and 1-10, and group C may include measurement circuits 1-6, 1-7, 1-8, and 1-9. If the number of measurement circuits n is 12 and the number of groups m is 3, the number of first-out, first-in memories 51 is four.

[0027] (When the number of groups m is 2) Among the measurement circuits 1-1 to 1-11 and the measurement circuit 7, group A may include measurement circuit 7, measurement circuit 1-1, measurement circuit 1-2, measurement circuit 1-3, measurement circuit 1-4, and measurement circuit 1-11, and group B may include measurement circuit 1-5, measurement circuit 1-6, measurement circuit 1-7, measurement circuit 1-8, measurement circuit 1-9, and measurement circuit 1-10. When the number of measurement circuits n is 12 and the number of groups m is 2, the number of first-out, first-in memories 51 is 6.

[0028] (Measurement circuit 1-1~1-11, 7) The n (n is a natural number of 2 or greater) measurement circuits 1 may be connected in series in a daisy chain, each measuring at least one of the voltage and current of each of the multiple batteries included in the battery pack and transmitting measurement data of a specific data size including the measured information. The n (n is a natural number of 2 or greater) measurement circuits may specifically include multiple measurement circuits 1-1 to 1-11 and measurement circuit 7. The daisy chain may be interpreted as a connection configuration in which three or more circuits are connected by cables for communication.

[0029] The specific data size includes the minimum unit of data amount required to encode at least one of the voltage and current of each of the multiple batteries, and each of the i first-in, first-out memories 51 may have a memory capacity k times (k is a natural number greater than or equal to 2) the data amount.

[0030] Each of the plurality of measurement circuits 1 may measure at least one of the voltage and current of each of the plurality of batteries included in the battery pack 200. Specifically, upon receiving a measurement start signal from the communication circuit 5, each of the plurality of measurement circuits 1 may start analog-to-digital conversion of at least one of the voltage and current, and transmit the analog-to-digital converted voltage and / or current to the battery manager 20 as measurement data. Note that the measurement circuit 7 may measure the current flowing through the battery pack 200, and transmit measurement data indicating the value of the measured current to the communication circuit 5.

[0031] Each of the plurality of measuring circuits 1 may monitor the state of each of the plurality of batteries included in the battery pack 200 and identify a battery in which a malfunction has occurred. Each of the plurality of measuring circuits 1 may set identification information for each of the plurality of measuring units 3-1 to 3-11 to identify each of the plurality of measuring circuits 1. This makes it possible to identify the location of the battery being monitored by the plurality of measuring units 3-1 to 3-11, i.e., the location of each of the plurality of batteries included in the battery pack 200. This also allows the battery manager 20 to identify the source of the received signal.

[0032] The measuring circuit 1-1 may include a measuring unit 3-1 and a communication unit 4-1. Similarly, the measuring circuit 1-2 may include a measuring unit 3-2 and a communication unit 4-2, the measuring circuit 1-3 may include a measuring unit 3-3 and a communication unit 4-3, and the measuring circuit 1-11 may include a measuring unit 3-11 and a communication unit 4-11. Each of the measuring units 3-1 to 3-11 may measure the voltage of the battery.

[0033] Although the present disclosure describes an example in which twelve measurement circuits 1 are used, the number of measurement circuits 1 is not limited to twelve, and may be two or more.

[0034] (Measurement section 3-1~Measurement section 3-11) Measurement unit 3-1 may measure the voltage generated across battery #1 and the current flowing through battery #1. Similarly, measurement unit 3-2 may measure the voltage generated across battery #2 and the current flowing through battery #2. Measurement unit 3-3 may measure the voltage generated across battery #3 and the current flowing through battery #3. Measurement unit 3-11 may measure the voltage generated across battery #11 and the current flowing through battery #11.

[0035] (Communications Department 4-1~4-11) The communication unit 4-1 is connected to the adjacent communication unit 4-2 so as to be able to communicate with each other. Similarly, the communication unit 4-2 is connected to the adjacent communication unit 4-3 so as to be able to communicate with each other. The communication unit 4-11 is connected to an adjacent communication unit (not shown) so as to be able to communicate with each other. In this way, a daisy chain is formed by connecting the adjacent communication units 4-1 to 4-11.

[0036] A serial communication line 6 is connected to the measurement circuit 1-1 that constitutes one end of the daisy chain, and another serial communication line 6 is connected to the measurement circuit 1-11 that constitutes the other end of the daisy chain. As a result, the communication units 4-1 to 4-11 and the communication circuit 5 are connected in a loop by the serial communication line 6.

[0037] The communication unit 4-1 may transmit measurement data indicating values ​​such as voltage and current measured by the measurement unit 3-1 to the communication circuit 5. Similarly, the communication unit 4-2 may transmit measurement data measured by the measurement unit 3-2 to the communication circuit 5. The communication unit 4-3 may transmit measurement data measured by the measurement unit 3-3 to the communication circuit 5. The communication unit 4-11 may transmit measurement data measured by the measurement unit 3-11 to the communication circuit 5.

[0038] Each of the multiple measurement circuits 1 configured in this manner starts measuring at least one of the voltage and current when it receives a measurement start signal from the battery manager 20 via the communication circuit 5 indicating that it should start measuring at least one of the voltage and current.

[0039] (Battery Manager 20) The battery manager 20 may manage each of the multiple batteries included in the battery pack 200. Specifically, the battery manager 20 may request measurement of at least one of the voltage and current of each of the multiple batteries included in the battery pack 200, collect measurement data in response to the request, and perform various controls based on the collected measurement data.

[0040] Next, the operation of the battery management system 100 will be described with reference to Figures 3A to 3D. Figures 3A to 3D are diagrams for explaining the operation of the battery management system 100 according to an embodiment of the present disclosure. Here, the operation will be described when the number n of measurement circuits 1 is 12, the number m of groups is 4, and the number of first-out, first-in memories 51 is 3.

[0041] As an example, the memory capacity of each FIFO memory 51 is set to twice the number of data packets (amount of data) sent from each measurement circuit 1, but the memory capacity of each FIFO memory 51 is not limited to twice the amount of data, and may be k times the amount of data (k is a natural number greater than or equal to 2) or more.

[0042] First, as shown in FIG. 3A, FIFO memory 51-1 stores measurement data from measurement circuit 1-1 in group A, FIFO memory 51-2 stores measurement data from measurement circuit 1-11 in group A, and FIFO memory 51-3 stores measurement data from measurement circuit 7 in group A.

[0043] 3B, FIFO memory 51-1 stores the measurement data from measurement circuit 1-2 in group B, FIFO memory 51-2 stores the measurement data from measurement circuit 1-3 in group B, and FIFO memory 51-3 stores the measurement data from measurement circuit 1-10 in group B. At this time, the measurement data that has already been stored is sent to battery manager 20. In other words, the measurement data is ordered first-in, first-out.

[0044] 3C, FIFO memory 51-1 stores the measurement data from measurement circuit 1-4 in group C, FIFO memory 51-2 stores the measurement data from measurement circuit 1-5 in group C, and FIFO memory 51-3 stores the measurement data from measurement circuit 1-9 in group C. At this time, the measurement data that has already been stored is transmitted to battery manager 20.

[0045] 3D, FIFO memory 51-1 stores the measurement data from measurement circuit 1-6 in group D, FIFO memory 51-2 stores the measurement data from measurement circuit 1-7 in group D, and FIFO memory 51-3 stores the measurement data from measurement circuit 1-8 in group D. At this time, the measurement data that has already been stored is transmitted to battery manager 20.

[0046] 4 is a diagram for explaining the memory capacity of a communication circuit 5A according to a comparative example. As shown in FIG. 4, the communication circuit 5A may include one first-in first-out memory 51A.

[0047] The communication circuit 5A stores multiple pieces of measurement data transmitted in chronological order from all of the measurement circuits 1 (measurement circuits 1-1 to 1-11 and measurement circuit 7) in a single first-in, first-out memory 51A, and transmits the stored multiple pieces of measurement data to the battery manager 20. FIG. 4 illustrates the total required FIFO memory capacity when there is one first-out, first-in memory 51A and the amount of data per cell is 18 bits. In this case, the total required FIFO memory capacity is 4968 bytes. In this way, the communication circuit 5A according to the comparative example temporarily stores the measurement data transmitted from the measurement circuits 1 (measurement circuits 1-1 to 1-11 and measurement circuit 7) that measure current and voltage in a single first-out, first-in memory 51A.

[0048] However, the data size of the measurement data received by the communication circuit 5A increases as the number of measurement circuits 1 increases and as the amount of measurement data transmitted by each measurement circuit 1 increases, which increases the memory capacity of the first-out, first-in memory 51A in the communication circuit 5A, and the increased memory capacity may increase the mounting area of ​​the battery management system 100.

[0049] (Action, effect) As described above, in the battery management system 100 of the present disclosure, the communication circuit 5 includes i (i is a natural number of 2 or more) first-in-first-out memories 51 that temporarily store measurement data in first-in, first-out order, and stores multiple pieces of measurement data in the first-in, first-out memories 51, each of which includes m (m is a natural number of 2 or more) groups, each of which includes two or more measurement circuits 1-1, etc., in chronological order, and transmits the stored multiple pieces of measurement data to the battery manager 20.

[0050] This configuration allows the memory capacity of the first-in first-out memory 51 included in the communication circuit 5 to be significantly smaller than in the comparative example described above. That is, it is possible to significantly suppress an increase in the memory capacity of the first-in first-out memory 51. Therefore, it is possible to suppress an increase in the mounting area of ​​the battery management system 100 due to an increase in the memory capacity of the first-in first-out memory 51.

[0051] In addition, the following supplementary notes are provided in relation to the above description.

[0052] (Appendix 1) n measurement circuits (n is a natural number of 2 or greater) connected in series in a daisy chain, each measuring at least one of the voltage and current of each of the plurality of batteries included in the battery pack and transmitting measurement data of a specific data size including the measurement information; a communication circuit that performs bidirectional communication with the n measurement circuits; a battery manager that manages each of the plurality of batteries; Equipped with The communication circuit i (i is a natural number equal to or greater than 2) first-in-first-out memories for temporarily storing the measurement data in a first-in-first-out order; A battery management system that stores a plurality of pieces of measurement data transmitted in chronological order from m groups (m is a natural number equal to or greater than 2) each including two or more of the measurement circuits in the first-in, first-out memory, and transmits the stored plurality of pieces of measurement data to the battery manager.

[0053] (Appendix 2) 2. The battery management system according to claim 1, wherein the number of the first-in, first-out memories corresponds to 1 / m times the number of the n measuring circuits.

[0054] (Appendix 3) the data size includes a minimum unit of data amount required to encode at least one of the voltage and the current of each of the plurality of batteries, 2. The battery management system according to claim 1, wherein each of the i first-in first-out memories has a memory capacity k times (k is a natural number equal to or greater than 2) the amount of data.

[0055] (Appendix 4) a first communication line for connecting the n measurement circuits to the communication circuit in the daisy chain and for bidirectional communication between the n measurement circuits and the communication circuit; a second communication line connecting the communication circuit to the battery manager for two-way communication between the communication circuit and the battery manager; Equipped with 2. The battery management system according to claim 1, wherein the data communication speed of the second communication line is equal to or greater than the data communication speed of the first communication line. [Explanation of symbols]

[0056] 1, 1-1, 1-2, 1-3, 1-11, 7 measurement circuit 3-1, 3-2, 3-3, 3-11, 4-1, 4-2, 4-3, 4-11 Communications Department 5, 5A communication circuit 6 serial communication lines 10. Communication Systems 11 CPU 12 Memory 20 Bus 20 Battery Manager 30 Network 51-1, 51-2, 51-3, 51A First-in, first-out memory 100 Battery Management System 200 battery packs

Claims

1. n measurement circuits (n is a natural number of 2 or greater) connected in series in a daisy chain, each measuring at least one of the voltage and current of each of a plurality of batteries included in the battery pack and transmitting measurement data of a specific data size including the measured information; a communication circuit for performing bidirectional communication with the n measurement circuits; a battery manager that manages each of the plurality of batteries; Equipped with The communication circuit i (i is a natural number equal to or greater than 2) first-in-first-out memories for temporarily storing the measurement data in a first-in-first-out order; A battery management system that stores a plurality of pieces of measurement data transmitted in chronological order from m groups (m is a natural number greater than or equal to 2) each including two or more of the measurement circuits in the first-in, first-out memory, and transmits the stored plurality of pieces of measurement data to the battery manager.

2. 2. The battery management system according to claim 1, wherein the number of said first-in first-out memories corresponds to 1 / m times the number of said n measuring circuits.

3. the data size includes a minimum unit of data amount required to encode at least one of the voltage and the current of each of the plurality of batteries, 2. The battery management system according to claim 1, wherein each of the i first-in-first-out memories has a memory capacity k times (k is a natural number equal to or greater than 2) the amount of data.

4. a first communication line for connecting the n measurement circuits to the communication circuit in the daisy chain and for bidirectional communication between the n measurement circuits and the communication circuit; a second communication line connecting the communication circuit to the battery manager for two-way communication between the communication circuit and the battery manager; Equipped with 2. The battery management system according to claim 1, wherein the data communication speed of the second communication line is equal to or higher than the data communication speed of the first communication line.

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