WO2021053976A1

WO2021053976A1 - Battery monitoring system, battery module, battery management device, management method, and vehicle

Info

Publication number: WO2021053976A1
Application number: PCT/JP2020/029475
Authority: WO
Inventors: 裕章武智
Original assignee: 住友電気工業株式会社
Priority date: 2019-09-19
Filing date: 2020-07-31
Publication date: 2021-03-25
Also published as: JPWO2021053976A1

Abstract

This battery monitoring system monitors a battery unit including a plurality of battery packs that include a first battery pack. The first battery back includes a plurality of cells. The battery monitoring system comprises: a first battery management device that manages the first battery pack; and a current sensor that detects the charge/discharge currents of the plurality of cells and outputs, to the first battery management device, a detection signal from the detection. The first battery management device comprises: a voltage acquisition unit that acquires the voltage between prescribed positions on a current path of the first battery pack; a current acquisition unit that acquires the charge/discharge currents of the plurality of cells through the current sensor; and a state estimation unit that estimates the state of the first battery pack using the voltage acquired by the voltage acquisition unit and the charge/discharge currents acquired by the current acquisition unit.

Description

Battery monitoring system, battery module, battery management device, management method, and vehicle

This disclosure relates to a battery monitoring system, a battery module, a battery management device, a management method, and a vehicle. This disclosure claims priority based on Japanese Application No. 2019-170709 filed on September 19, 2019, and incorporates all the contents of the Japanese application.

In response to increasing energy constraints such as crude oil and the need for measures against global warming, the number of electric vehicles represented by EV (Electric Vehicle), HEV (Hybrid Electric Vehicle), etc. is increasing worldwide. Such electric vehicles are equipped with a secondary battery that supplies electric power to an electric motor for driving the vehicle.

In order to keep the secondary battery in the optimum condition for a long period of time, it is necessary to monitor the battery condition and manage the battery.

Patent Documents

1 and 2 described later disclose a battery system having such a battery management function.

The system disclosed in Patent Document 1 includes a battery module to which an assembled battery having a plurality of cells is connected, a plurality of battery monitoring circuits provided corresponding to each assembled battery, and a microcomputer that controls the operation of each battery monitoring circuit. And include. Each battery monitoring circuit monitors the state of the assembled battery based on an instruction from the microcomputer. A plurality of battery monitoring circuits are connected in series via a capacitor and a relay signal transmission line.

The system disclosed in Patent Document 2 includes a plurality of power storage modules each having an assembled battery and a monitoring IC (Integrated Circuit), and a BMU (Battery Management Unit) that centrally manages each power storage module. Each power storage module (monitoring IC) is communicably connected to the BMU by a daisy chain connection via an isolator and a communication line.

JP-A-2017-168453 Japanese Unexamined Patent Publication No. 2019-30134 Japanese Unexamined Patent Publication No. 2015-224927 Japanese Unexamined Patent Publication No. 2009-210478 Japanese Unexamined Patent Publication No. 2018-013456 Japanese Unexamined Patent Publication No. 2017-203659 JP-A-2017-194284 Japanese Unexamined Patent Publication No. 2017-194283

The battery monitoring system according to a certain aspect of the present disclosure is a battery monitoring system that monitors a battery unit including a plurality of assembled batteries including the first assembled battery. The first set battery includes a plurality of cells. This battery monitoring system includes a first battery management device that manages the first assembled battery, and a current sensor that detects charge / discharge currents of a plurality of cells and outputs the detection signal to the first battery management device. Including. The first battery management device includes a voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the first assembled battery, and a current acquisition unit that acquires charge / discharge currents of a plurality of cells via a current sensor. Includes a state estimation unit that estimates the state of the first assembled battery using the voltage acquired by the voltage acquisition unit and the charge / discharge current acquired by the current acquisition unit.

The battery module according to another aspect of the present disclosure is provided in an assembled battery including a plurality of cells, a battery management device for managing the assembled battery, and a current path of the assembled battery, and detects charge / discharge currents of the plurality of cells. It includes a current sensor that outputs the detection signal to the battery management device. The battery management device is acquired by a voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the assembled battery, a current acquisition unit that acquires charge / discharge currents of a plurality of cells via a current sensor, and a voltage acquisition unit. It includes a state estimation unit that estimates the state of the assembled battery using the voltage and the charge / discharge current acquired by the current acquisition unit.

The battery management device according to still another aspect of the present disclosure is a battery management device that manages an assembled battery including a plurality of cells. The current path of the assembled battery is provided with a current sensor that detects the charge / discharge currents of a plurality of cells and outputs the detection signal to the battery management device. This battery management device includes a voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the assembled battery, a current acquisition unit that acquires charge / discharge currents of a plurality of cells via a current sensor, and a voltage acquisition unit. It includes a state estimation unit that estimates the state of the assembled battery using the acquired voltage and the charge / discharge current acquired by the current acquisition unit.

A method according to yet another aspect of the present disclosure is a method of managing an assembled battery including a plurality of cells. A current sensor that detects the charge / discharge currents of a plurality of cells is provided in the current path of the assembled battery. This management method includes a step of measuring the voltage between predetermined positions in the current path of the assembled battery, a step of acquiring a detection signal output from the current sensor, and a step of measuring the charge / discharge currents of a plurality of cells, and a step of measuring. Including the step of estimating the state of the assembled battery using the voltage and charge / discharge current measured in.

The vehicle according to still another aspect of the present disclosure includes the above-mentioned battery monitoring system and an in-vehicle control device that communicates with the battery monitoring system and acquires predetermined information from the battery monitoring system.

The technology of the present disclosure can not only be realized as a battery monitoring system including such a characteristic configuration. The technique of the present disclosure can also be realized as a program for causing a computer to perform a characteristic step performed by a battery monitoring system, and as a recording medium on which the program is recorded. Further, the system may include a battery unit instead of the battery management system alone. Further, it can be a semiconductor integrated circuit that realizes a part or all of the components of the battery monitoring system and the battery management device, a battery reuse system using information processed by the battery management device, and further. It can also be other systems, including.

FIG. 1 is a block diagram showing an example of a main part configuration of a vehicle equipped with the battery monitoring system according to the first embodiment. FIG. 2 is a block diagram showing a configuration example of the battery monitoring system and the battery unit shown in FIG. FIG. 3 is a block diagram showing a functional configuration example of the battery management device constituting the battery monitoring system. FIG. 4 is a diagram showing an equivalent circuit model of a secondary battery represented by a combination of a resistor and a capacitor. FIG. 5 is a diagram showing an equivalent circuit model of a secondary battery represented by a combination of a resistor and a capacitor. FIG. 6 is a diagram showing an equivalent circuit model of a secondary battery represented by a combination of a resistor and a capacitor. FIG. 7 is a block diagram showing a functional configuration example of the state estimation unit in the battery management device. FIG. 8 is a diagram schematically showing the relationship between the parameters and the functional blocks related to the estimation of the charge rate. FIG. 9 is a block diagram showing a functional configuration example of the battery monitoring device constituting the battery monitoring system. FIG. 10 is a flowchart showing an example of a control structure of a program executed by the battery management device. FIG. 11 is a flowchart showing an example of a control structure of a program executed by the battery management device. FIG. 12 is a flowchart showing an example of a control structure of a program executed by the battery management device. FIG. 13 is a flowchart showing an example of a control structure of a program executed by the battery monitoring device. FIG. 14 is a block diagram showing a configuration example of the battery monitoring system and the battery unit according to the second embodiment. FIG. 15 is a block diagram showing a configuration example of the battery monitoring system and the battery unit according to the third embodiment. FIG. 16 is a block diagram showing a functional configuration example of the battery monitoring device constituting the battery monitoring system shown in FIG.

[Issues to be solved by this disclosure]
In the systems of

Patent Documents

1 and 2, a plurality of battery monitoring circuits (monitoring ICs) are connected in series. Therefore, a communication delay occurs between the microcomputer or BMU that manages the battery monitoring circuit and the battery monitoring circuit. In particular, when the number of assembled batteries connected is increased in order to increase the battery voltage, the number of battery monitoring circuits connected in series also increases, so that the communication delay becomes large. As a result, the simultaneity of communication data is impaired, and there is a problem that the estimation accuracy is lowered when estimating the state of the battery.

Therefore, it is an object of the present disclosure to provide a battery monitoring system, a battery module, a battery management device, a management method, and a vehicle capable of accurately estimating the state of a battery.

[Effect of the present disclosure]
According to the present disclosure, it is possible to provide a battery monitoring system, a battery module, a battery management device, a management method, and a vehicle capable of accurately estimating the state of a battery.

[Explanation of Embodiments of the present disclosure]
First, preferred embodiments of the present disclosure will be listed and described. In addition, at least a part of the embodiments described below may be arbitrarily combined.

(1) The battery monitoring system according to a certain aspect of the present disclosure is a battery monitoring system that monitors a battery unit including a plurality of assembled batteries including the first assembled battery. The first set battery includes a plurality of cells. This battery monitoring system includes a first battery management device that manages the first assembled battery, and a current sensor that detects charge / discharge currents of a plurality of cells and outputs the detection signal to the first battery management device. Including. The first battery management device includes a voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the first assembled battery, and a current acquisition unit that acquires charge / discharge currents of a plurality of cells via a current sensor. Includes a state estimation unit that estimates the state of the first assembled battery using the voltage acquired by the voltage acquisition unit and the charge / discharge current acquired by the current acquisition unit.

The current sensor detects the charge / discharge currents of a plurality of cells and outputs the detection signal to the battery management device. In the first battery management device, the voltage acquisition unit acquires the voltage between predetermined positions in the current path of the first assembled battery, and the current acquisition unit acquires the charge / discharge currents of a plurality of cells via the current sensor. To do. Since the cell voltage value and charge / discharge current value can be acquired without a time lag, data simultaneity is ensured. As a result, the influence of the phase shift between the cell voltage and the charge / discharge current can be suppressed, so that the state can be estimated accurately when the state estimation unit estimates the state of the assembled battery.

The voltage acquisition unit is configured to acquire at least one of the voltage of each of the plurality of cells and the voltage of the assembled battery including the plurality of cells as the voltage between predetermined positions in the current path of the assembled battery. Is preferable. It is more preferable that the state estimation unit for estimating the state of the assembled battery includes at least one of a configuration for estimating the state of the entire assembled battery and a configuration for estimating the state of each of the plurality of cells included in the assembled battery.

(2) Preferably, the plurality of assembled batteries further include a second assembled battery different from the first assembled battery, the second assembled battery further includes a plurality of cells, and the battery management system further includes a second set. The current of the second battery management device that manages the batteries and the current of the second battery pack that detects the charge / discharge currents of a plurality of cells of the second battery pack and outputs the detection signal to the second battery management device. The second battery management device, including the sensor, includes a voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the second assembled battery, and a second battery management device via the current sensor of the second assembled battery. The current acquisition unit that acquires the charge / discharge currents of a plurality of cells of the assembled battery, the voltage acquired by the voltage acquisition unit of the second battery management device, and the charge / discharge current acquired by the current acquisition unit of the second battery management device. It includes a state estimation unit that estimates the state of the second assembled battery by using it. As a result, the voltage value and charge / discharge current value of the cell can be easily acquired without a time lag, so that the simultaneity of data can be easily ensured.

(3) More preferably, a battery monitoring device for monitoring the battery unit is further included, and each of the first battery management device and the second battery management device further includes a communication unit that communicates with the battery monitoring device, and the first The communication unit of the battery management device and the communication unit of the second battery management device are the first set estimated by the state estimation unit of the first battery management device and the state estimation unit of the second battery management device, respectively. The status of the battery and the second assembled battery are transmitted to the battery monitoring device, respectively. In

Patent Documents

1 and 2 described above, the battery monitoring circuits are daisy-chained via a communication line. Therefore, if the communication line is disconnected even at one location, the data communication between all the battery monitoring circuits and the microcomputer or BMU is interrupted. On the other hand, in the present disclosure, for example, the communication unit of the first battery management device and the communication unit of the second battery management device individually set the state of the first assembled battery and the second assembled battery, respectively. Send to the monitoring device. Therefore, even if a communication problem occurs between some battery management devices and the battery monitoring device, the other battery management devices are not affected by the problem. Since other battery management devices can maintain communication with the battery monitoring device, the estimated battery status can be transmitted to the battery monitoring device. Therefore, the battery monitoring device can monitor the battery unit even when a communication problem occurs with some battery management devices.

(4) More preferably, the communication unit of the first battery management device and the communication unit of the second battery management device are further the current acquisition unit of the first battery management device and the current acquisition unit of the second battery management device. Sends the charge / discharge currents acquired by each to the battery monitoring device, and the battery monitoring device of the first and second battery management devices is based on the charge / discharge currents transmitted from the first and second battery management devices. In response to the sensor abnormality detection unit that detects the abnormality of at least one current sensor and the sensor abnormality detection unit detecting the abnormality of the current sensor of the first or second battery management device, the first or second Among the current sensors of the battery management device, the abnormality notification unit that notifies the battery management device of the current sensor in which the abnormality is detected of the sensor abnormality is included. As a result, each battery management device can recognize the abnormality of the current sensor, so that the deterioration of the estimation accuracy due to the abnormality of the current sensor can be suppressed.

(5) More preferably, the first and second battery management devices can communicate with each other, and the first battery management device responds to the reception of the sensor abnormality from the abnormality notification unit. , Acquires the charge / discharge current of the second assembled battery by communicating with the second battery management device. As a result, even if a sensor abnormality occurs in some current sensors, the state of the battery can be estimated accurately.

(6) More preferably, the first battery management device is further based on at least one information of the voltage and the charge / discharge current acquired by the voltage acquisition unit and the current acquisition unit in the first battery management device, respectively. It includes an abnormality determination unit that determines whether or not the assembled battery of 1 is abnormal and executes an abnormality process according to the determination result. As a result, the occurrence of an abnormality can be detected at an early stage and the abnormality processing can be executed, so that the assembled battery (and thus the battery unit) can be effectively managed.

(7) More preferably, the first battery management device further preferably uses the cell of the first assembled battery based on the voltage acquired by the voltage acquisition unit in the first battery management device and the state estimated by the state estimation unit. Includes a cell balance circuit that performs balancing. Since the state estimation unit can accurately estimate the state of the assembled battery, the energy capacity between the cells can be accurately equalized by using the estimated state. As a result, the capacity of the battery can be fully utilized.

(8) More preferably, the state estimation unit of the first battery management device is set in the first set based on the voltage and charge / discharge current acquired by the voltage acquisition unit and the current acquisition unit in the first battery management device, respectively. It includes a parameter estimation unit that estimates the parameters of the battery equivalent circuit model. As a result, the parameters of the equivalent circuit model can be estimated accurately.

(9) More preferably, the voltage acquisition unit of the first battery management device acquires the voltage of each of the plurality of cells in the first assembled battery, and the state estimation unit of the first battery management device is the first. The state of each of the plurality of cells of the assembled battery is estimated, and the first battery management device identifies the state of each of the plurality of cells estimated by the state estimation unit of the first battery management device to identify the plurality of cells. It further includes a recording unit that records in association with the identification information to be recorded. For example, the state of the battery unit can be accurately grasped by reading the history information recorded in the recording unit at the time of reuse.

The battery management device may further include a temperature acquisition unit that acquires the temperature of the cell, and the state estimation unit may be configured to estimate the state of the assembled battery by further using the temperature acquired by the temperature acquisition unit. As a result, the state of the battery can be estimated more accurately. Further, the abnormality determination unit may determine whether or not the assembled battery is abnormal based on the temperature information acquired by the temperature acquisition unit. Thereby, the abnormality of the assembled battery can be detected from various viewpoints. In addition, the cell balance circuit may also perform cell balance of the assembled battery based on the temperature acquired by the temperature acquisition unit. As a result, the cell balance of the assembled battery can be executed more accurately.

(10) The battery module according to another aspect of the present disclosure is provided in an assembled battery including a plurality of cells, a battery management device for managing the assembled battery, and a current path of the assembled battery, and is provided with charge / discharge currents of the plurality of cells. Includes a current sensor that detects and outputs the detection signal to the battery management device. The battery management device is acquired by a voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the assembled battery, a current acquisition unit that acquires charge / discharge currents of a plurality of cells via a current sensor, and a voltage acquisition unit. It includes a state estimation unit that estimates the state of the assembled battery using the voltage and the charge / discharge current acquired by the current acquisition unit.

The current sensor provided in the current path of the assembled battery detects the charge / discharge currents of a plurality of cells and outputs the detection signal to the battery management device. The battery management device acquires the voltage between predetermined positions in the current path of the assembled battery at the voltage acquisition unit, and acquires the charge / discharge currents of a plurality of cells at the current acquisition unit via the current sensor. Since the cell voltage value and charge / discharge current value can be acquired without a time lag, data simultaneity is ensured. As a result, the influence of the phase shift between the cell voltage and the charge / discharge current can be suppressed, so that the state can be estimated accurately when the state estimation unit estimates the state of the assembled battery. In addition, since the assembled battery, the battery management device, and the current sensor are modularized, they can be reused in module units. The voltage acquisition unit is configured to acquire at least one of the voltage of each of the plurality of cells and the voltage of the assembled battery including the plurality of cells as the voltage between predetermined positions in the current path of the assembled battery. Is preferable. It is more preferable that the state estimation unit for estimating the state of the assembled battery includes at least one of a configuration for estimating the state of the entire assembled battery and a configuration for estimating the state of each of the plurality of cells included in the assembled battery.

(11) Preferably, the voltage acquisition unit acquires the voltage of each of the plurality of cells, and the state estimation unit acquires the voltage and current of each of the plurality of cells acquired by the voltage acquisition unit. The battery management device includes a cell state estimation unit that estimates the state of each of a plurality of cells using an electric current, and the battery management device corresponds the states of the plurality of cells estimated by the cell state estimation unit with identification information that identifies the plurality of cells. It further includes a recording unit for attaching and recording. As a result, the state of the battery unit can be accurately grasped by reading the history information recorded in the recording unit.

(12) The battery management device according to still another aspect of the present disclosure is a battery management device that manages an assembled battery including a plurality of cells. The current path of the assembled battery is provided with a current sensor that detects the charge / discharge currents of a plurality of cells and outputs the detection signal to the battery management device. This battery management device includes a voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the assembled battery, a current acquisition unit that acquires charge / discharge currents of a plurality of cells via a current sensor, and a voltage acquisition unit. It includes a state estimation unit that estimates the state of the assembled battery using the acquired voltage and the charge / discharge current acquired by the current acquisition unit. By using such a battery management device, the state of the battery can be estimated accurately. The voltage acquisition unit is configured to acquire at least one of the voltage of each of the plurality of cells and the voltage of the assembled battery including the plurality of cells as the voltage between predetermined positions in the current path of the assembled battery. Is preferable. It is more preferable that the state estimation unit for estimating the state of the assembled battery includes at least one of a configuration for estimating the state of the entire assembled battery and a configuration for estimating the state of each of the plurality of cells included in the assembled battery.

(13) A method according to still another aspect of the present disclosure is a method of managing an assembled battery including a plurality of cells. A current sensor that detects the charge / discharge currents of a plurality of cells is provided in the current path of the assembled battery. This management method includes a step of measuring the voltage between predetermined positions in the current path of the assembled battery, a step of acquiring a detection signal output from the current sensor, and a step of measuring the charge / discharge currents of a plurality of cells, and a step of measuring. Including the step of estimating the state of the assembled battery using the voltage and charge / discharge current measured in. As a result, the state of the battery can be estimated accurately. The step of measuring is a configuration in which at least one of the voltage of each of the plurality of cells and the voltage of the assembled battery including the plurality of cells is acquired as the voltage between the predetermined positions in the current path of the assembled battery. And more preferable. It is more preferable that the step of estimating the state of the assembled battery includes a step of estimating the state of each of the plurality of cells included in the assembled battery.

(14) The vehicle according to still another aspect of the present disclosure includes the above-mentioned battery monitoring system and an in-vehicle control device that communicates with the battery monitoring system and acquires predetermined information from the battery monitoring system. The in-vehicle control device can efficiently control the battery unit based on the information from the battery monitoring system. As a result, the battery unit can be kept in an optimum state for a long period of time.

[Details of Embodiments of the present disclosure]
Specific examples of the battery monitoring system, the battery module, the battery management device, the management method, and the vehicle according to the embodiment of the present disclosure will be described below with reference to the drawings. In the following embodiments, the same parts are given the same reference number. Their functions and names are also the same. Therefore, detailed explanations about them will not be repeated.

(First Embodiment)
[overall structure]
With reference to FIG. 1, the vehicle 20 according to the present embodiment is, for example, an electric vehicle such as an EV or HEV. The vehicle 20 is a battery monitoring system that monitors a battery unit 50 to which a plurality of assembled batteries 40_1 to 40_n (hereinafter, collectively referred to as “combined battery 40”) including a plurality of cells 30 are connected, and the battery unit 50. Includes 100 and. The vehicle 20 further includes a relay 60, an inverter 62, a motor 64, a DC / DC converter 66, an auxiliary battery 68, an electric load 70, a start switch 72, and an upper ECU (Electronic Control Unit) 74.

The battery unit 50 includes a rechargeable secondary battery. The secondary battery includes, for example, a lithium ion battery. The battery unit 50 has a configuration in which a plurality of assembled batteries 40 in which a plurality of cells 30 are connected in series are further connected in series.

The battery monitoring system 100 is a plurality of battery management devices (BMU: Battery Management Unit) 110_1 to 110_n (hereinafter, collectively referred to as "battery management device 110") that manage a plurality of assembled batteries 40 included in the battery unit 50. A battery monitoring device 300 that is communicably connected to each of the plurality of battery management devices 110_1 to 110_n. The plurality of battery management devices 110_1 to 110_n are provided corresponding to the respective assembled batteries 40_1 to 40_n of the battery unit 50, and manage the corresponding assembled batteries 40, respectively. The battery monitoring device 300 monitors the battery unit 50 based on the information transmitted from the battery management devices 110_1 to 110_n.

The relay 60 is a switch that is turned on / off by a relay control unit (not shown). The relay 60 is connected between the positive electrode side of the battery unit 50, the input side of the inverter 62, and the input side of the DC / DC converter 66. When the relay 60 is turned on, the electric circuit connecting the battery unit 50, the inverter 62 and the DC / DC converter 66 is closed, and when the relay 60 is turned off, the electric circuit is opened.

The output side of the inverter 62 is connected to one end of the motor 64, and the DC power supplied from the battery unit 50 via the relay 60 is converted into AC power and output to the motor 64. Specifically, the inverter 62 controls the energization of the motor 64 while the relay 60 is on by a command from a vehicle controller (not shown). The motor 64 produces a driving force for turning wheels (not shown) by the AC power converted by the inverter 62. The DC / DC converter 66 is a step-down converter that converts high-voltage DC power supplied from the battery unit 50 via a relay 60 into low-voltage DC power. The DC / DC converter 66 is also an isolated converter, and insulates the high-voltage side where the battery unit 50 is arranged and the low-voltage side where the auxiliary battery 68, the electric load 70, and the like are arranged. The output side of the DC / DC converter 66 is connected to the positive electrode side of the auxiliary battery 68, one end of the electric load 70, and one end of the start switch 72. The DC / DC converter 66 supplies the converted low-voltage DC power to the auxiliary battery 68 and the electric load 70.

The auxiliary battery 68 is, for example, a 12V lead storage battery. The auxiliary battery 68 supplies electric power to the electric load 70 and is charged by the electric power supplied from the DC / DC converter 66 while the relay 60 is on. The auxiliary battery 68 is not limited to a voltage of 12 V or a lead storage battery.

The electric load 70 includes an auxiliary machine load operated by the DC power of the auxiliary battery 68. More specifically, the electric load 70 includes, for example, a low voltage load such as an ECU, a headlight, and an interior light. The start switch 72 is a switch for starting the vehicle 20. The upper ECU 74 includes, for example, an ECU that controls the amount of power supply (discharge) and the amount of regeneration (charge) with the motor 64 based on the information transmitted from the battery monitoring system 100.

The negative electrode side of the battery unit 50 and the other end of the motor 64 are connected to the common potential on the high voltage side, and the negative electrode side of the auxiliary battery 68 and the other end of the electric load 70 are connected to the common potential on the low voltage side. ing.

[Hardware configuration]
With reference to FIG. 2, the battery monitoring system 100 according to the present embodiment detects a plurality of charge currents and discharge currents (hereinafter, referred to as “charge / discharge currents”) of each assembled battery 40 for each assembled battery 40. The current sensors 180_1 to 180_n (hereinafter, collectively referred to as “current sensor 180”) are included. The plurality of current sensors 180_1 to 180_n are arranged corresponding to each assembled battery 40, and are provided in the current paths of the corresponding assembled batteries 40, respectively. Each current sensor 180 detects the charge / discharge current of the corresponding assembled battery 40 (cell 30) and outputs the detection signal to the battery management device 110 that manages the corresponding assembled battery 40. The current sensor 180 is composed of, for example, a shunt resistor or a Hall sensor, and converts the charge / discharge current of the assembled battery 40 (cell 30) into a voltage signal. The sampling period of the current sensor 180 is, for example, 10 milliseconds, but is not limited to this. The current sensor 180 may be provided inside the assembled battery 40 or may be provided outside the assembled battery 40.

The current sensor 180 and the battery management device 110 are provided for each set battery 40 so as to correspond to each set battery 40. The assembled battery 40, the current sensor 180, and the battery management device 110, which correspond to each other, are modularized as a set, and a plurality of battery modules 200_1 to 200_n (hereinafter, collectively referred to as "battery module 200"). It is described.). The battery monitoring device 300 centrally manages the plurality of battery modules 200_1 to 200_n by communicating with each of the plurality of battery management devices 110.

The battery management device 110 estimates the state of the assembled battery 40 on a cell-by-cell basis, and manages the assembled battery 40 and each cell 30. The battery management device 110 identifies each of the assembled battery 40 and each cell 30 by using the identification information (ID) when managing the assembled battery 40 and each cell 30. Here, each assembled battery 40 is identified as an assembled battery_1, an assembled battery_2, ..., An assembled battery_n by using, for example, an assembled battery ID from 1 to n. The cell 30 included in each set battery 40 is identified by using, for example, the cell IDs 001 to x.

The plurality of battery management devices 110_1 to 110_n all have the same configuration. Therefore, in the following, the configuration of the battery management device 110_1 will be described on behalf of the plurality of battery management devices 110_1 to 110_n.

The battery management device 110_1 includes a cell voltage detection / balance circuit 112, a temperature detection circuit 114, a current detection circuit 116, a power supply circuit 118, a communication unit 120, a memory 122, and a control device 124 for controlling them. Including. The control device 124 includes, for example, a processing device such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit).

The cell voltage detection / balance circuit 112 is a circuit that detects the voltage of the cell 30 included in the assembled battery 40 separately (for each cell) and executes cell balance. The cell voltage detection / balance circuit 112 detects the voltage across the cell 30 at a predetermined sampling cycle, and outputs information indicating the detected voltage to the control device 124. The sampling period is, for example, 10 milliseconds, but is not limited to this.

The temperature detection circuit 114 detects the surface temperature of one or a plurality of locations of the assembled battery 40 based on a voltage signal converted from temperature to voltage by a temperature sensor (not shown) such as a thermistor included in the assembled battery 40. It is a circuit. As the temperature sensor, a known temperature sensor other than the thermistor may be used. For example, as the temperature sensor, a resistance temperature detector, a semiconductor temperature sensor, a thermoelectric pair, or the like may be used. The current detection circuit 116 is a circuit in which the current sensor 180 detects the charge / discharge current of the assembled battery 40 (cell 30) based on the voltage signal converted from current to voltage.

The power supply circuit 118 is a circuit that converts the electric power supplied from the assembled battery 40 (battery unit 50) into a voltage suitable for driving each component of the battery management device 110_1 and supplies power to each component of the battery management device 110_1. Is. The communication unit 120 wirelessly communicates with the battery monitoring device 300. The memory 122 is a non-volatile storage device such as a flash memory. The management device identification information (BMU-ID) for identifying the own device is stored in the non-rewritable area of the memory 122. Here, it is assumed that the plurality of battery management devices 110 are identified as BMU_1, BMU_2, ..., BMU_n by using, for example, BMU-IDs 1 to n. The management device identification information of the battery management device 110_1 is BMU_1. The memory 122 further stores information generated by the processing of the control device 124. The software (computer program) executed by the control device 124 is stored in advance in the control device 124. The software (computer program) executed by the control device 124 may be configured to be stored in the memory 122 in advance.

The battery monitoring device 300 includes a communication unit 310, a power supply unit 312, a memory 314, a communication unit 316, and a control device 318 for controlling these. The communication unit 310 wirelessly communicates with each battery management device 110. The power supply unit 312 converts the electric power from the battery unit 50 into a predetermined voltage value and supplies it to each component unit. The memory 314 is a non-volatile storage device such as a flash memory. The memory 314 stores the management device identification information (BMU-ID) of each of the plurality of battery management devices 110 connected to the own device. The management device identification information may be stored in advance by setting, or the control device 318 may send and receive information to and from each battery management device 110 to collect the management device identification information. Identification information (assembled battery ID, cell ID) for identifying the assembled battery 40 or the cell 30 may be stored in the memory 314 for each assembled battery 40 or each cell 30.

The communication unit 316 can transmit and receive information to and from other in-vehicle devices by, for example, CAN (Control Area Network). The communication unit 316 communicates with the upper ECU 74 (see FIG. 1) via the in-vehicle LAN (Local Area Network). The communication unit 316 may be a wired communication module that communicates with other in-vehicle devices by wire, or may be a wireless communication module having a wireless communication antenna. The control device 318 includes, for example, a processing device such as a CPU or an MPU. The software (computer program) executed by the control device 318 is stored in advance in the control device 318. The software (computer program) executed by the control device 318 may be configured to be stored in the memory 314 in advance.

With reference to FIG. 3, the control device 124 of the battery management device 110 includes a control unit 130, a voltage acquisition unit 132, a current acquisition unit 134, a temperature acquisition unit 136, a communication control unit 138, an ID management unit 140, and a memory management unit 142. , Timer 144, state estimation unit 146, cell balance control unit 152, and abnormality determination unit 154 are included as functional units. The functions of these functional units are realized by software processing executed by the control device 124 using hardware. Some or all of these functions may be realized by integrated circuits including a microcomputer. The frequency of acquiring the voltage and current controlled by the control device 124 is, for example, 10 milliseconds, but the frequency is not limited to this. The temperature is acquired in a timely manner.

The control device 124 controls each unit as the control unit 130, and calculates the battery characteristics of the assembled battery 40 in cell units based on the detected voltage, temperature, and current. The control device 124 has, for example, full charge capacity (FCC: Full Charge Capacity), charge rate (SOC: State of Charge), deterioration degree (SOH: State of Health), charge / discharge possible power (SOP: State of Power) as battery characteristics. ), And the internal parameters of the equivalent circuit model are calculated. Information for calculating these battery characteristics is stored in advance in the memory 122. For example, information referred to for calculating the charge rate (SOC) for each cell is stored in the memory 122. For example, in the memory 122, the correlation between the open circuit voltage (OCV: Open Circuit Voltage) of the unit battery (

cell

30 or 40 units of the assembled battery) and the charge rate is stored in advance. The memory 122 further stores the initial (when new) full charge capacity or internal parameters of each unit battery as information for calculating the degree of deterioration of each unit battery. Further, as information for calculating the degree of deterioration, the correlation between the internal resistance increase rate and the discharge capacity ratio may be stored in the memory 122. It is preferable that the full charge capacity or the internal parameters can be read separately, such as being stored in the order of connection of the unit batteries. It is preferable that the memory 122 stores the relationship between the rate of increase in internal resistance and the discharge capacity ratio corresponding to the degree of deterioration as information for calculating the degree of deterioration for each unit battery.

The voltage acquisition unit 132 acquires information indicating the voltage across the assembled battery 40 or the terminal voltage of each cell 30 output from the cell voltage detection / balance circuit 112. The voltage acquisition unit 132 may acquire the voltage across the assembled battery 40 and the voltage in each of the cells 30 separately from each other. The current acquisition unit 134 acquires information indicating the charge / discharge current flowing through the assembled battery 40 (cell 30) output from the current detection circuit 116. The temperature acquisition unit 136 acquires information indicating the temperature output from the temperature detection circuit 114.

The communication control unit 138 interfaces with the communication unit 120. The ID management unit 140 manages the management device identification information (BMU-ID) of the own device, the assembled battery ID of the assembled battery 40 managed by the own device, and the cell ID of each cell 30 included in the assembled battery 40. .. The memory management unit 142 manages the memory 122. The memory management unit 142 also executes a process of recording various information indicating the battery characteristics (battery status) calculated for each cell in the memory 122, a process of reading the recorded battery characteristics (battery status), and the like. .. The timer 144 clocks the time and outputs the timed result to the control unit 130. The control unit 130 associates the time information with the battery characteristics based on the output from the timer 144 in order to store the calculated battery characteristics in time series.

The state estimation unit 146 includes a parameter estimation unit 148 and a battery state estimation unit 150. The parameter estimation unit 148 estimates internal parameters that are the values of resistors and capacitors that represent the equivalent circuit model of cell 30. Since these internal parameters change depending on the charge rate, temperature, deterioration degree, etc. of the cell 30, they can be sequentially estimated by observing the voltage and charge / discharge current of each cell 30.

With reference to FIG. 4, a method of estimating the internal parameters of the equivalent circuit model by the parameter estimation unit 148 will be described. The equivalent circuit model is represented by a circuit in which a resistor Ra and a parallel circuit of a resistor Rb and a capacitor Cb are connected in series to a voltage source using an OCV as an electromotive force. The resistor Ra corresponds to the electrolyte resistance. The resistor Rb corresponds to the charge transfer resistance and the capacitor Cb corresponds to the electric double layer capacitance. The charge transfer resistance may be included in the resistance Ra, and the resistance Rb may correspond to the diffusion resistance. It is known that the following approximate equations (1) to (4) hold for the internal parameters of the equivalent circuit model shown in FIG. 4 (see Non-Patent Document 1 for details).

uL (k) = b0 ・ i (k) + b1 ・ i (k-1) -a1 ・ uL (k-1)
) + (1 + a1) · OCV ... (1)
b0 = Ra ・・・・・・・・・・・・・・・・ (2)
b1 = TsRa / (RbCb) + Ts / Cb-Ra ... (3)
a1 = Ts / (RbCb) -1 ... (4)
However,
uL: Acquired voltage i: Acquired charge / discharge current Ts: Measurement cycle k: Integer indicating the measurement time point.

When the internal parameters Ra, Rb and Cb are calculated back from the above equations (2) to (4), the following equations (5) to (7) are established.

Ra = b0 ・・・・・・・・・・・・・ (5)
Rb = (b1-a1b0) / (1 + a1) ... (6)
Cb = Ts / (b1-a1b0) ・・・・・・・・・・・・・ (7)

In the present embodiment, the successive least squares method is applied to the equation (1) to determine the coefficients b0, b1 and a1, and the determined coefficients are substituted into the equations (5) to (7) to substitute the parameters Ra, Rb and Estimate Cb. The estimated parameters may be corrected according to the temperature acquired by the temperature acquisition unit 136.

The parameters Ra, Rb and Cb can also be calculated using a Kalman filter. Specifically, the observation vector when the input signal represented by the voltage and the charge / discharge current is given to the cell 30 and the state vector when the same input signal as above is given to the equivalent circuit model of the cell 30 are obtained. By comparing and multiplying these errors by Kalman gain and feeding them back to the equivalent circuit model, the modification of the equivalent circuit model is repeated so that the errors of both vectors are minimized. As a result, the parameters are estimated.

The equivalent circuit model of the secondary battery is not limited to the one shown in FIG. For example, as shown in FIG. 5, the nth order represented by the sum of infinite series, in which n parallel circuits of the resistor Rj and the capacitor Cj (j = 1, 2, ..., N) are connected in series to the resistor R0. It may be a Foster type RC ladder circuit (n is a natural number). Further, as shown in FIG. 6, the other ends of the n resistors Rj (j = 1, 2, ..., N) whose ends are connected to each other are connected between the n capacitors Cj connected in series. It may be the nth-order Cowell type RC ladder circuit.

With reference to FIG. 3 again, the battery state estimation unit 150 estimates the state of the assembled battery 40 on a cell-by-cell basis. Specifically, the battery state estimation unit 150 estimates the charge rate (SOC), the degree of deterioration (SOH), the chargeable / dischargeable power (SOP), and the like for each cell 30 of the assembled battery 40. The battery state estimation unit 150 may estimate the state of the assembled battery 40 in units of assembled batteries.

With reference to FIG. 7, the battery state estimation unit 150 includes a current integration unit 160, a charge rate estimation unit 162, a full charge capacity calculation unit 164, a deterioration degree calculation unit 166, and a chargeable / dischargeable power calculation unit 168. including.

The current integrating unit 160 integrates the value of the charge / discharge current acquired by the current acquisition unit 134. The integrated value of the current is the integral value of the current over time, and corresponds to the change in the amount of charge. The integrated value of the current is positive in the case of charging and negative in the case of discharging. The integrated value in an arbitrary period can be positive or negative depending on the magnitude of the charge current and discharge current values in the period. The timing for starting the calculation of the integration can be the start timing of the battery unit 50, the battery module 200, or the battery management device 110 (battery monitoring system 100) itself. The integrated value is calculated continuously. The integrated value may be reset at a predetermined timing, for example, in the case of reuse, at the timing of rearranging the battery module 200.

A method of estimating the charge rate by the charge rate estimation unit 162 will be described with reference to FIG. The charge rate estimation unit 162 estimates the charge rate using a Kalman filter. The charge rate estimation unit 162 estimates the SOC to be output based on the voltage acquired by the voltage acquisition unit 132, the charge / discharge current acquired by the current acquisition unit 134, and the internal parameters estimated by the parameter estimation unit 148.

Specifically, the charge rate estimation unit 162 generates a state vector representing the state of the cell 30 after processing the internal parameters estimated by the parameter estimation unit 148 with parameter data, and also generates a voltage acquisition unit 132 and a current acquisition unit 132. An observation vector representing the observation value based on the acquisition result in 134 is generated. The charge rate estimation unit 162 further updates the state of the cell 30 using a Kalman filter based on these vectors to estimate the charge rate of the cell 30. Since the estimation of the charge rate using the Kalman filter is described in detail in Patent Document 3, detailed description thereof will be omitted.

With reference to FIG. 7 again, the full charge capacity calculation unit 164 calculates the full charge capacity for each cell in cell units. The full charge capacity calculation unit 164 can also calculate the full charge capacity of 40 units of the assembled battery based on the full charge capacity of each cell 30.

The deterioration degree calculation unit 166 calculates the deterioration degree for each unit battery which is the assembled battery 40 or the cell 30. For example, the deterioration degree calculation unit 166 calculates the deterioration degree by comparing the full charge capacity of the unit battery calculated by the full charge capacity calculation unit 164 with the initial full charge capacity stored in the memory 122. The deterioration degree calculation unit 166 obtains the ratio (increase degree) of the internal resistance value R calculated by the parameter estimation unit 148 to the initial value for each cell 30, and the internal resistance increase rate and discharge stored in the memory 122. It may be configured to calculate the degree of deterioration based on the correlation with the capacity ratio. Further, even if the deterioration degree calculation unit 166 is configured to calculate the deterioration degree by comparing the initial value of the internal parameter stored in the memory 122 with the value calculated by the parameter estimation unit 148. Good.

The charge / discharge possible power calculation unit 168 includes an OCV calculated based on the integrated value of the charge / discharge current calculated by the current integration unit 160, an OCV estimated by the parameter estimation unit 148, and an internal parameter estimated by the parameter estimation unit 148. (For example, internal resistance, etc.) and the charge / discharge current acquired by the current acquisition unit 134 are used to calculate the chargeable / dischargeable power of the assembled battery 40 in cell units. The charge / discharge possible power calculation unit 168 may calculate the charge / discharge possible power based on the OCV, the internal parameters, the charge / discharge current, and the temperature.

The above-mentioned state estimation unit 146 serves as a parameter estimation unit 148, a charge rate estimation unit 162, a full charge capacity calculation unit 164, a deterioration degree calculation unit 166, and a chargeable / dischargeable power calculation unit 168, and is a state of each cell 30 in the assembled battery 40. (Battery characteristics) can be calculated by various methods. As a method for calculating (estimating) the state (battery characteristics) of each cell 30, for example, the methods disclosed in Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 7, Patent Document 8 and the like can be used. ..

With reference to FIG. 3 again, the cell balance control unit 152 controls the cell voltage detection / balance circuit 112 to perform cell balance on the assembled battery 40 managed by the own device. Specifically, the cell balance control unit 152 includes the voltage acquired by the voltage acquisition unit 132, the state estimated by the state estimation unit 146 (for example, the charge rate of each cell 30 estimated by the charge rate estimation unit 162, etc.), and The cell voltage detection / balance circuit 112 is controlled so as to equalize the energy capacities of the plurality of cells 30 based on the temperature acquired by the temperature acquisition unit 136 or an instruction from the battery monitoring device 300.

The abnormality determination unit 154 has an abnormality in the assembled battery 40 managed by its own device based on the voltage acquired by the voltage acquisition unit 132, the charge / discharge current acquired by the current acquisition unit 134, the temperature acquired by the temperature acquisition unit 136, and the like. Judge whether or not. Specifically, for example, each threshold value for determining whether or not it is abnormal is stored in the memory 122. The abnormality determination unit 154 determines whether or not the assembled battery 40 is abnormal by comparing each detection value from the voltage acquisition unit 132, the current acquisition unit 134, or the temperature acquisition unit 136 with each threshold value. The abnormality determination unit 154 may be configured to determine the abnormality of each cell 30 by comparing with other cells 30. The abnormality determination unit 154 further executes a predetermined abnormality processing in response to the determination that the assembled battery 40 is abnormal. As an abnormality measure, the abnormality determination unit 154 notifies, for example, the battery monitoring device 300 that the assembled battery 40 is abnormal, and records the history information in the memory 122.

The control device 124 calculates all or part of the battery characteristics such as the charge rate, the internal parameters, the full charge capacity, and the degree of deterioration in a predetermined cycle such as 10 milliseconds as the control unit 130, and temporarily stores the battery characteristics. Charge / discharge control is performed according to the battery characteristics. The control unit 130 transmits the battery characteristics to the battery monitoring device 300. The battery monitoring device 300 calculates the battery characteristics of the entire battery unit 50 based on the battery characteristics transmitted from each battery management device 110, and executes charge / discharge control as a whole. The battery monitoring device 300 further provides information for traveling control and the like to the upper ECU 74. In addition to the battery characteristics (battery state) estimated by the own device, each battery management device 110 is acquired by the voltage acquired by the voltage acquisition unit 132, the charge / discharge current acquired by the current acquisition unit 134, and the temperature acquisition unit 136. It may be configured to transmit information such as temperature to the battery monitoring device 300.

With reference to FIG. 2 again, when the start switch 72 (FIG. 1) is turned on, or when the battery unit 50 is being charged by the charger (not shown) while the vehicle 20 is stopped. The battery monitoring system 100 operates in the normal mode. In the normal mode, the battery monitoring device 300 acquires and aggregates information such as battery characteristics (battery status) from each battery management device 110 at a predetermined cycle such as 1 second. On the other hand, when the start switch 72 (FIG. 1) is not turned on and the battery is not charged, the battery monitoring system 100 operates in the low power consumption mode. In the low power consumption mode, the battery monitoring system 100 is activated at regular intervals, and operates in the same manner as in the normal mode for a predetermined time.

With reference to FIG. 9, the control device 318 of the battery monitoring device 300 includes a control unit 320, an inter-module cell balance control unit 322, a communication control unit 324, a timer 326, a memory management unit 328, and an abnormality determination unit 330 as functional units. Include as. The functions of these functional units are realized by software processing executed by the control device 318 using hardware. Some or all of these functions may be realized by integrated circuits including a microcomputer.

The inter-module cell balance control unit 322 controls each battery management device 110 based on the aggregated information of each battery module 200 (each assembled battery 40) so as to suppress the variation in energy capacity between the battery modules 200. Specifically, the cell balance control unit 322 between modules generates a command value for suppressing the variation in energy capacity between the battery modules 200, and the generated command value is transmitted to each battery management device 110 via the communication unit 310. Send to. Each battery management device 110 performs cell balance based on a command value transmitted from the battery monitoring device 300 to equalize the energy capacity of each cell 30 as a plurality of battery modules 200, that is, the battery unit 50 as a whole. To do.

The communication control unit 324 takes an interface with the communication unit 310 and the communication unit 316. The timer 326 clocks the time and outputs the timed result to the control unit 320. The control unit 320 associates the time information with the battery characteristics based on the output from the timer 326 in order to store the battery characteristics (battery state) acquired from each battery management device 110 in time series. The memory management unit 328 manages the memory 314. The memory management unit 328 also executes a process of recording various information including battery characteristics acquired from each battery management device 110 in the memory 314, a process of reading the recorded battery characteristics (battery state) from the memory 314, and the like. To do. The abnormality determination unit 330 determines whether or not an abnormality has occurred in each battery module 200 based on the information acquired from each battery management device 110, and executes a predetermined abnormality process according to the determination result. For example, the abnormality determination unit 330 determines an abnormality in each battery module 200 (assembled battery 40) by comparing with another battery module 200 (assembled battery 40). When the deviation from the value of the battery characteristics (battery state) is larger than that of many other battery modules 200, it can be determined that the battery module 200 is abnormal. In addition to this, for example, the abnormality determination of the battery module 200 may be performed by comparing with a predetermined threshold value.

[Software configuration]
A control structure of a computer program executed by each battery management device 110 in order to manage the assembled battery 40 included in the battery module 200 will be described with reference to FIGS. 10 to 13. This program starts in response to the transition to the normal mode or at regular intervals in the low power consumption mode.

With reference to FIG. 10, this program includes step S1000, which repeats steps S1010 to S1070 described below for the transmission cycle to the battery monitoring device 300. In step S1000, the state of the battery is estimated.

In step S1000, the process of estimating the battery state, which is repeated during the transmission cycle to the battery monitoring device 300, controls the cell voltage detection / balance circuit 112 to measure the voltage of each cell 30. It is executed after step S1010 to control the current detection circuit 116 to measure the charge / discharge current of the assembled battery 40 (each cell 30), and is executed after step S1020 to control the temperature detection circuit 114. , It is executed after step S1030 to measure the surface temperature of the assembled battery 40, and it is determined whether or not there is an abnormality in the assembled battery 40 or each cell 30 based on the information measured in steps S1010 to S1030. Then, in step S1040 for branching the control flow according to the determination result, step S1050 which is executed when it is determined that there is an abnormality in step S1040 and a predetermined abnormality processing is executed, and step S1040 where there is no abnormality. It includes step S1060, which is executed when the determination is made and executes a process of estimating the internal parameters of the equivalent circuit model, and step S1070, which is executed after step S1060 and estimates the state of the assembled battery 40 in cell units. In step S1050, for example, a process of storing the abnormality of the cell 30 in the memory 122 as history information is executed. In step S1050, the abnormality of the cell 30 is temporarily stored for transmission to the battery monitoring device 300.

This program is further executed after step S1000 to transmit the abnormality of cell 30 or the estimated battery characteristics (battery state) to the battery monitoring device 300, and is executed after step S1080, and the operation mode is usually Execution when it is determined in step S1090 and step S1090 that the mode or not is determined and the control flow is branched according to the determination result, that the operation mode is not the normal mode, that is, the low power consumption mode is determined. This includes step S1100, which determines whether or not a predetermined time for operating as the normal mode has elapsed, and branches the control flow according to the determination result. If it is determined in step S1090 that the operation mode is the normal mode, or if it is determined in step S1100 that the predetermined time has not elapsed, the control returns to step S1000. If it is determined in step S1100 that the predetermined time has elapsed, the execution of this program ends.

FIG. 11 is a routine showing the communication interrupt process in the battery management device 110. This routine is activated in response to, for example, detecting an abnormality in the assembled battery 40 (for example, a sudden temperature rise, etc.) for which immediate action is desired, or receiving an instruction from the battery monitoring device 300. To. With reference to FIG. 11, this routine includes step S1200, which executes an interrupt process for a request from the battery management device 110 or a request from the battery monitoring device 300. In step S1200, when the battery management device 110 detects any abnormality, the battery monitoring device 300 is notified of the abnormality. In step S1200, when the instruction from the battery monitoring device 300 is received, the process according to the received instruction is executed. When the process of step S1200 is completed, the execution of this routine ends.

FIG. 12 is a routine showing the cell balance interrupt processing in the battery management device 110. This routine is activated in response to a cell balance instruction from the battery management device 110 itself or a cell balance instruction from the battery monitoring device 300. With reference to FIG. 12, this routine includes step S1300, which executes the cell balance in response to the cell balance instruction as an interrupt process. When the process of step S1300 is completed, the execution of this routine ends.

With reference to FIG. 13, the control structure of the computer program executed by the battery monitoring device 300 in order to monitor the entire battery unit 50 will be described. This program, like the battery management device 110, starts in response to the transition to the normal mode or at regular intervals in the low power consumption mode.

This program is executed after step S2000 for receiving the information transmitted from each battery management device 110 and after step S2000, and is the state of each cell 30 and each battery module 200 (assembled battery 40) based on the received information. In step S2010 and step S2020, which are executed after step S2010, determine whether or not there is an abnormality in the cell 30 or the assembled battery 40, and branch the control flow according to the determination result. It is executed when it is determined that there is an abnormality, and is executed when it is determined that there is no abnormality in step S2030 and step S2020, which executes a predetermined abnormality processing, and whether or not there is an instruction to the battery management device 110. Step S2040 that determines and branches the control flow according to the determination result, and step S2050 that is executed when it is determined that there is an instruction in step S2040 and transmits the instruction to the battery management device 110 to be instructed. And step S2060, which is executed after step S2030 or step S2050, or when it is determined in step S2040 that there is no instruction, and transmits information necessary for battery management to the upper ECU 74.

In step S2040, for example, whether or not there is an instruction to the battery management device 110 for each battery module 200 depending on whether or not it is necessary to perform cell balance for each battery module 200 (assembled battery 40). judge. In step S2050, a cell balance instruction is transmitted to the battery management device 110. The cell balance instruction includes an instruction as to which cell 30 of which battery module 200 the cell balance operation is to be executed. In step S2030, for example, a process of temporarily storing an abnormality in the battery unit 50 (assembled battery 40 or cell 30) in order to transmit it to the higher-level ECU 74 is executed. In step S2060, information regarding the abnormality of the battery unit 50 or information such as the battery status is transmitted to the upper ECU 74. The information to be transmitted to the upper ECU 74 is not all the information about the cell 30, but is preselected such as the average value, the lowest value, the highest value, etc. regarding the charge rate (SOC), the degree of deterioration (SOH), the internal resistance, the temperature, and the like. It may be an item. Further, the item requested from the upper ECU 74 may be transmitted to the upper ECU 74.

This program is further executed after step S2060, determines whether or not the operation mode is the normal mode, and branches the control flow according to the determination result. In step S2070 and step S2070, the operation mode is not the normal mode. That is, in step S2080, which is executed when the low power consumption mode is determined, it is determined whether or not a predetermined time for operating as the normal mode has elapsed, and the control flow is branched according to the determination result. including. If it is determined in step S2070 that the operation mode is the normal mode, or if it is determined in step S2080 that the predetermined time has not elapsed, the control returns to step S2000. If it is determined in step S2080 that the predetermined time has elapsed, the execution of this program ends.

[motion]
The battery monitoring system 100 according to the present embodiment operates as follows.

The battery monitoring system 100 operates in the normal mode when the start switch 72 is turned on or when the battery is charged by a charger (not shown) while the vehicle is stopped. On the other hand, when the start switch 72 is not turned on and the battery is not charged while the vehicle is stopped, the battery monitoring system 100 operates in the low power consumption mode. In the low power consumption mode, the battery monitoring system 100 is started at regular intervals and operates for a predetermined period in the same manner as in the normal mode.

In the normal mode, each battery management device 110 acquires the voltage, charge / discharge current, and surface temperature of each cell 30 of the corresponding assembled battery 40 (steps S1010 to S1030 in FIG. 10). Each battery management device 110 determines whether or not there is an abnormality in the assembled battery 40 (cell 30) based on the acquired information. If it is determined that there is an abnormality (YES in step S1040), the battery management device 110 executes a predetermined abnormality process (step S1050). When there is no abnormality (NO in step S1040), each battery management device 110 uses the acquired voltage, charge / discharge current, and temperature to perform battery characteristics such as charge rate, internal parameters, full charge capacity, and degree of deterioration (NO). Battery status) is estimated (step S1060 and step S1070). Each battery management device 110 repeats these series of processes (steps S1010 to S1070) at a predetermined cycle such as 10 milliseconds.

Each battery management device 110 transmits information such as a battery status to the battery monitoring device 300 at a predetermined cycle such as 1 second. When the transmission cycle to the battery monitoring device 300 is 1 second and the cycle of the series of processes is 10 milliseconds, each battery management device 110 repeats the processes of steps S1010 to S1070 100 times each time. The information obtained by the above process is transmitted to the battery monitoring device 300.

When each battery management device 110 detects some abnormality for which immediate response is desired, or receives an instruction from the battery monitoring device 300, each battery management device 110 executes an interrupt process corresponding to the instruction (step S1200 in FIG. 11). .. When each battery management device 110 further determines that it is necessary to perform cell balance based on the charge rate of the cell 30, or when it receives a cell balance instruction from the battery monitoring device 300, the cell balance is adjusted. The interrupt process to be performed is executed (step S1300 in FIG. 12).

The battery monitoring device 300 receives the information transmitted from each battery management device 110 and grasps the state of the assembled battery 40 and each cell 30 for each battery module 200 (steps S2000 and S2010 in FIG. 13). The battery monitoring device 300 determines whether or not there is an abnormality in each assembled battery 40 (each cell 30) in the battery unit 50 based on the state of each cell 30 or the information regarding the abnormality transmitted from the battery management device 110. When it is determined that there is an abnormality (YES in step S2020), the battery monitoring device 300 notifies the upper ECU 74 of this (step S2030 and step S2060). Further, when the battery monitoring device 300 detects an abnormality such that the state of a certain battery module 200 is significantly different from the state of another battery module 200 based on the state of each battery module 200, the battery module 200 is further detected. Notifies (battery management device 110) of a battery abnormality.

When there is no abnormality in each assembled battery 40 (each cell 30) (NO in step S2020), the battery monitoring device 300 determines whether or not there is a variation in the energy capacity between the battery modules 200. That is, it is determined whether or not it is necessary to give a cell balance instruction to the battery management device 110. When it is necessary to give a cell balance instruction (YES in step S2040), the battery monitoring device 300 transmits the cell balance instruction to the battery module 200 (battery management device 110) (step S2050) and also gives the cell balance instruction. This is notified to the upper ECU 74 (step S2060). On the other hand, when it is not necessary to give the cell balance instruction (NO in step S2040), the battery monitoring device 300 transmits the information necessary for battery management in the higher ECU 74 to the higher ECU 74 (step S2060).

When the operation mode is the normal mode (YES in step S1090 in FIG. 10 and step S2070 in FIG. 13), the battery monitoring system 100 repeats the above operation. When the operation mode is the low power consumption mode, the above operation is repeated during a predetermined time during which the same operation as the normal mode is performed (NO in step S1100 in FIG. 10 and step S2080 in FIG. 13).

[Effect of this embodiment]
As is clear from the above description, the battery monitoring system 100 and the like according to the present embodiment have the effects described below.

In each battery module 200, the current sensor 180 provided in the current path of the assembled battery 40 detects the charge / discharge current of the cell 30 and outputs the detection signal to the battery management device 110. Each battery management device 110 acquires the voltage of the cell 30 by the voltage acquisition unit 132, and acquires the charge / discharge current of the cell 30 by the current acquisition unit 134 via the current sensor 180. Since the voltage value and charge / discharge current value of each cell 30 can be acquired without a time difference, the simultaneity of data is ensured. As a result, the influence of the phase shift between the voltage of the cell 30 and the charge / discharge current can be suppressed, so that the state can be estimated accurately when the state estimation unit 146 estimates the state of the assembled battery 40.

Each of the plurality of battery management devices 110 individually transmits the state of the assembled battery 40 (each cell 30) estimated by the state estimation unit 146 to the battery monitoring device 300 via the communication unit 120. Therefore, unlike the configuration in which the battery is connected in a daisy chain, even if a communication problem occurs between some battery management devices 110 and the battery monitoring device 300, the other battery management devices 110 are affected by the problem. I will not receive it. Since the other battery management device 110 can maintain communication with the battery monitoring device 300, the estimated state of the assembled battery 40 can be transmitted to the battery monitoring device 300. Therefore, the battery monitoring device 300 can monitor the battery unit 50 even when a communication problem occurs with some of the battery management devices 110.

In each battery management device 110, the assembled battery 40 (cell 30) is based on the voltage acquired by the voltage acquisition unit 132, the charge / discharge current acquired by the current acquisition unit 134, and the temperature information acquired by the temperature acquisition unit 136. Determine if it is abnormal. Each battery management device 110 executes an abnormality process according to the determination result. As a result, the occurrence of an abnormality can be detected at an early stage and the abnormality processing can be executed, so that the assembled battery 40 (and thus the battery unit 50) can be effectively managed. Further, the battery monitoring device 300 can centrally manage the information of each battery management device 110, so that the battery unit 50 can be monitored more effectively.

Each battery management device 110 further adjusts the cell balance of the assembled battery 40 based on the voltage acquired by the voltage acquisition unit 132, the state estimated by the state estimation unit 146 (battery characteristics), and the temperature acquired by the temperature acquisition unit 136. Run. Since the state estimation unit 146 can accurately estimate the state of the assembled battery 40 on a cell-by-cell basis, the energy capacity between the cells 30 can be accurately uniformized by using the estimated state. As a result, the capacity of the battery can be fully utilized.

The assembled battery 40, the battery management device 110, and the current sensor 180 are modularized as a battery module 200. The battery monitoring system 100 can even estimate the state of the batteries in each of the plurality of battery modules 200. By combining a plurality of such battery modules 200, the battery monitoring system 100 according to the present embodiment can be easily configured. In battery reuse, it is possible to facilitate reuse in module units.

Each battery management device 110 further records the state of each cell estimated by the state estimation unit 146 in the memory 122 in association with the identification information that identifies the cell 30. As a result, the state of the battery unit 50 can be accurately grasped by reading the history information recorded in the memory 122 at the time of reuse or the like.

In the vehicle 20 equipped with such a battery monitoring system 100, the battery monitoring system 100 and the upper ECU 74 communicate with each other, and the upper ECU 74 sets the battery unit 50 based on the information from the battery monitoring system 100 (battery monitoring device 300). Can be controlled efficiently. As a result, the battery unit 50 can be kept in an optimum state for a long period of time.

(Second Embodiment)
The battery monitoring system according to the first embodiment is the same as the battery monitoring system 100 according to the first embodiment (see FIG. 2) in that one current sensor outputs detection signals to a plurality of battery management devices. Is different. Other configurations are the same as in the first embodiment.

With reference to FIG. 14, the battery monitoring system 100A according to the present embodiment includes a plurality of battery management devices 110 (110_1, 110_2, ..., 110_n) for managing each set of batteries 40 of the battery unit 50. .. Similar to the first embodiment, the plurality of battery management devices 110 are provided corresponding to the plurality of assembled batteries 40. The battery monitoring system 100A includes a battery monitoring device similar to the battery monitoring device 300 (see FIG. 2). However, in FIG. 14, the description of the battery monitoring device is omitted.

A plurality of current sensors 180 are provided in the current path of each assembled battery 40. However, the number of current sensors 180 is smaller than the number of assembled batteries 40. Therefore, some of the current sensors 180 out of the plurality of current sensors 180 output detection signals to the plurality of battery management devices 110. That is, some of the current sensors 180 are shared by the plurality of battery management devices 110.

Specifically, the assembled battery 40_2 is provided with the current sensor 180, and the assembled battery 40_n is also provided with the current sensor 180. On the other hand, the assembled battery 40_1 is not provided with the current sensor 180. Therefore, the detection signal from the current sensor 180 of the assembled battery 40_1 is input to the battery management device 110_1 that manages the assembled battery 40_1. Since the plurality of cells 30 are connected in series, the charge / discharge currents of the cells 30 have the same value. Therefore, even if one current sensor 180 is configured to output detection signals to a plurality of battery management devices 110_1 and 110_2, each battery management device 110_1 and 110_2 is a battery assembly as in the first embodiment. The 40 states can be estimated accurately on a cell-by-cell basis. Further, by sharing a part of the current sensors 180 with a plurality of battery management devices 110_1 and 110_2, the number of installed current sensors 180 can be reduced. As a result, a cost reduction effect can be expected.

Although the present embodiment has shown an example in which a plurality of current sensors 180 are provided, the present disclosure is not limited to such a configuration. For example, one current sensor 180 may be provided as a battery monitoring system, and the one current sensor 180 may output detection signals to all of the plurality of battery management devices 110_1 to 110_n.

(Third Embodiment)
With reference to FIG. 15, in the battery management system 100B according to the present embodiment, a plurality of battery management devices 110 are connected in series via a communication line 400, and the battery monitoring device 300 (see FIG. 2). Instead, it differs from the battery monitoring system 100 according to the first embodiment in that it includes the battery monitoring device 300A. The battery monitoring device 300A includes a control device 318A instead of the control device 318 (see FIG. 2). The communication line 400 is preferably connected to the battery management device 110 via an isolator such as a photocoupler or a capacitor. As a result, the plurality of battery management devices 110 are maintained in a state of being insulated from each other.

Each battery management device 110 transmits the charge / discharge current of each cell 30 to the battery monitoring device 300A at a predetermined cycle via the communication unit 120.

With reference to FIG. 16, the control device 318A of the battery monitoring device 300A further includes a sensor abnormality detection unit 332 and an abnormality notification unit 334 as functional units. The sensor abnormality detection unit 332 detects an abnormality in the current sensor 180 based on the charge / discharge current transmitted from each battery management device 110. Specifically, the sensor abnormality detection unit 332 detects an abnormality of the current sensor 180 by, for example, comparing the aggregated charge / discharge current values with each other. Since the plurality of cells 30 are connected in series, the values of the charge / discharge currents detected by the current sensor 180 are basically the same. Therefore, when the value of the charge / discharge current transmitted from a certain battery management device 110 is different from the value of many other charge / discharge currents, the cause is a failure or detection of the current sensor 180 corresponding to the battery management device 110. It is possible that the wiring that transmits the signal is broken. Therefore, by comparing the aggregated charge / discharge current values with each other, the sensor abnormality detection unit 332 can detect the abnormality of the current sensor 180.

When the sensor abnormality detection unit 332 detects an abnormality in the current sensor 180, the abnormality notification unit 334 sends a detection signal from the current sensor 180 in which the abnormality is detected to the battery management device 110 via the communication control unit 324. Notify the sensor abnormality.

The battery management device 110 notified of the sensor abnormality acquires a charge / discharge current (information indicating the charge / discharge current) from another battery management device 110 via the communication line 400. For example, the battery management device 110 notified of the sensor abnormality communicates with the adjacent battery management device 110 to acquire the charge / discharge current from the battery management device 110. As a result, even if a sensor abnormality occurs in some of the current sensors 180, the state of the battery can be estimated accurately.

The battery monitoring device 300A provides not only the battery management device 110 to which the detection signal from the current sensor 180 in which the abnormality is detected is input, but also the battery management device 110 to provide the value of the charge / discharge current. The device 110 may also be configured to notify the sensor abnormality. In this case, it is preferable that the battery management device 110 that has received the notification is configured to transmit the charge / discharge current value to the battery management device 110 instructed by the battery monitoring device 300A.

(Modification example)
In the above embodiment, an example in which the battery monitoring system is mounted on the vehicle has been shown, but the present disclosure is not limited to such an embodiment. For example, the battery monitoring system may be used to monitor the stationary storage battery.

In the above embodiment, an example using a cell voltage detection / balance circuit that detects cell voltage separately and executes cell balance is shown, but the present disclosure is not limited to such an embodiment. The cell voltage detection and the cell balance execution may be performed by separate circuits.

The battery management device constituting the battery monitoring system may be configured to estimate the state of the assembled battery using the voltage of the assembled battery, or may be configured to estimate the state of the cell using the voltage of the cell. Good. The battery management device may further be configured to estimate the state of both the assembled battery and the cell using the respective voltages of the assembled battery and the cell.

In the above embodiment, an example of detecting an abnormality in the assembled battery (cell) based on voltage, charge / discharge current, and temperature information in each battery management device has been shown, but the present disclosure shows such an embodiment. It is not limited to the form. The detection of anomalies in each battery management device can also be based on at least one piece of information: voltage, charge / discharge current, and temperature.

In the above embodiment, an assembled battery in which cells are connected in series and a battery unit are shown, but the present disclosure is not limited to such an embodiment. The assembled battery and the cells constituting the battery unit may be connected in series-parallel, for example.

In the above embodiment, an example in which the battery management device and the battery monitoring device communicate wirelessly is shown, but the present disclosure is not limited to such an embodiment. The communication between the battery management device and the battery monitoring device may be, for example, wired communication such as isolated CAN communication.

In the above embodiment, an example of a battery monitoring system that does not include a battery unit has been shown, but the present disclosure is not limited to such an embodiment. The battery monitoring system may be configured to include a battery unit to be monitored.

The embodiments obtained by appropriately combining the techniques disclosed above are also included in the technical scope of the present disclosure.

The embodiments disclosed this time are merely examples, and the present disclosure is not limited to the above-described embodiments. The scope of the present disclosure is indicated by each claim of the claims, taking into consideration the description of the detailed description of the invention, and includes all changes within the meaning and scope equivalent to the wording described therein. ..

20 Vehicle 30 cells 40, 40_1 to 40_n battery 50 Battery unit 60 Relay 62 Inverter 64 Motor 66 DC / DC converter 68 Auxiliary battery 70 Electric load 72 Start switch 74 Upper ECU
100, 100A, 100B Battery monitoring system 110, 110_1 to 110_n Battery management device 112 Cell voltage detection / balance circuit 114 Temperature detection circuit 116 Current detection circuit 118

Power supply circuit

120, 310, 316

Communication unit

122, 314

Memory

124, 318,

318A Control device

130, 320 Control unit 132 Voltage acquisition unit 134 Current acquisition unit 136

Temperature acquisition unit

138, 324 Communication control unit 140

ID management unit

142, 328

Memory management unit

144, 326 Timer 146 State estimation unit 148 Parameter estimation unit 150 Battery status Estimator 152 Cell

balance control unit

154, 330 Abnormality determination unit 160 Current integration unit 162 Charge rate estimation unit 164 Full charge capacity calculation unit 166 Deterioration degree calculation unit 168 Charge / dischargeable power calculation unit 180, 180_1 to 180_n Current sensor 200, 200_1 ~

200_n Battery module

300, 300A Battery monitoring device 312 Power supply unit 322 Cell balance control unit between modules 332 Sensor abnormality detection unit 334 Abnormality notification unit 400 Communication line

Claims

A battery monitoring system that monitors a battery unit including a plurality of assembled batteries including the first assembled battery, wherein the first assembled battery includes a plurality of cells.
The battery monitoring system is
A first battery management device that manages the first assembled battery,
It includes a current sensor that detects the charge / discharge currents of the plurality of cells and outputs the detection signal to the first battery management device.
The first battery management device is
A voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the first assembled battery, and a voltage acquisition unit.
A current acquisition unit that acquires charge / discharge currents of the plurality of cells via the current sensor, and a current acquisition unit.
A battery monitoring system including a state estimation unit that estimates the state of the first assembled battery using the voltage acquired by the voltage acquisition unit and the charge / discharge current acquired by the current acquisition unit.
The plurality of assembled batteries further include a second assembled battery different from the first assembled battery.
The second assembled battery includes a plurality of cells and contains a plurality of cells.
The battery management system further
A second battery management device that manages the second assembled battery, and
Including the current sensor of the second assembled battery, which detects the charge / discharge currents of the plurality of cells of the second assembled battery and outputs the detection signal to the second battery management device.
The second battery management device is
A voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the second assembled battery, and a voltage acquisition unit.
A current acquisition unit that acquires charge / discharge currents of the plurality of cells of the second assembled battery via the current sensor of the second assembled battery, and a current acquisition unit.
The state of the second assembled battery is estimated using the voltage acquired by the voltage acquisition unit of the second battery management device and the charge / discharge current acquired by the current acquisition unit of the second battery management device. The battery monitoring system according to claim 1, which includes a state estimation unit.
A battery monitoring device for monitoring the battery unit is further included.
Each of the first battery management device and the second battery management device further includes a communication unit that communicates with the battery monitoring device.
The communication unit of the first battery management device and the communication unit of the second battery management device are the state estimation unit of the first battery management device and the state estimation of the second battery management device. The battery monitoring system according to claim 2, wherein the states of the first assembled battery and the second assembled battery, which are estimated by each unit, are transmitted to the battery monitoring device, respectively.
The communication unit of the first battery management device and the communication unit of the second battery management device further include the current acquisition unit of the first battery management device and the current acquisition of the second battery management device. The charge / discharge current acquired by each unit is transmitted to the battery monitoring device, and the charge / discharge current is transmitted to the battery monitoring device.
The battery monitoring device is
A sensor abnormality detection unit that detects an abnormality in at least one of the current sensors of the first and second battery management devices based on the charge / discharge current transmitted from the first and second battery management devices. ,
Of the current sensors of the first or second battery management device, in response to the sensor abnormality detection unit detecting an abnormality of the current sensor of the first or second battery management device. The battery monitoring system according to claim 3, further comprising an abnormality notification unit for notifying the battery management device of the current sensor in which an abnormality has been detected.
The first and second battery management devices can communicate with each other and can communicate with each other.
The first battery management device acquires the charge / discharge current of the second assembled battery by communicating with the second battery management device in response to receiving the sensor abnormality from the abnormality notification unit. , The battery monitoring system according to claim 4.
The first battery management device further increases the first battery management device based on at least one of the voltage acquired by the voltage acquisition unit and the current acquisition unit and the charge / discharge current in the first battery management device. The battery monitoring system according to any one of claims 1 to 5, further comprising an abnormality determination unit that determines whether or not the assembled battery is abnormal and executes an abnormality process according to the determination result.
The first battery management device further adjusts the cell balance of the first assembled battery based on the voltage acquired by the voltage acquisition unit in the first battery management device and the state estimated by the state estimation unit. The battery monitoring system according to any one of claims 1 to 6, which includes a cell balance circuit to be executed.
The state estimation unit of the first battery management device is the first assembled battery based on the voltage and charge / discharge current acquired by the voltage acquisition unit and the current acquisition unit in the first battery management device, respectively. The battery monitoring system according to any one of claims 1 to 7, further comprising a parameter estimation unit that estimates the parameters of the equivalent circuit model of the above.
The voltage acquisition unit of the first battery management device acquires the voltage of each of the plurality of cells in the first assembled battery, and obtains the voltage of each of the plurality of cells.
The state estimation unit of the first battery management device estimates the state of each of the plurality of cells of the first assembled battery.
The first battery management device records each state of the plurality of cells estimated by the state estimation unit of the first battery management device in association with identification information that identifies the plurality of cells. The battery monitoring system according to any one of claims 1 to 8, further comprising a part.
An assembled battery containing multiple cells and
A battery management device that manages the assembled batteries and
It includes a current sensor provided in the current path of the assembled battery, detecting charge / discharge currents of the plurality of cells, and outputting the detection signal to the battery management device.
The battery management device is
A voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the assembled battery, and a voltage acquisition unit.
A current acquisition unit that acquires charge / discharge currents of the plurality of cells via the current sensor, and a current acquisition unit.
A battery module including a state estimation unit that estimates the state of the assembled battery using the voltage acquired by the voltage acquisition unit and the charge / discharge current acquired by the current acquisition unit.
The voltage acquisition unit acquires the voltage of each of the plurality of cells, and obtains the voltage of each of the plurality of cells.
The state estimation unit estimates the state of each of the plurality of cells by using the voltage of each of the plurality of cells acquired by the voltage acquisition unit and the charge / discharge current acquired by the current acquisition unit. Including part
The battery according to claim 10, wherein the battery management device further includes a recording unit that records the states of the plurality of cells estimated by the cell state estimation unit in association with identification information that identifies the plurality of cells. module.
A battery management device that manages an assembled battery containing a plurality of cells.
The current path of the assembled battery is provided with a current sensor that detects the charge / discharge currents of the plurality of cells and outputs the detection signal to the battery management device.
The battery management device is
A voltage acquisition unit that acquires a voltage between predetermined positions in the current path of the assembled battery, and a voltage acquisition unit.
A current acquisition unit that acquires charge / discharge currents of the plurality of cells via the current sensor, and a current acquisition unit.
A battery management device including a state estimation unit that estimates the state of the assembled battery using the voltage acquired by the voltage acquisition unit and the charge / discharge current acquired by the current acquisition unit.
It is a method of managing an assembled battery containing multiple cells.
A current sensor for detecting the charge / discharge currents of the plurality of cells is provided in the current path of the assembled battery.
The management method is
A step of measuring the voltage between predetermined positions in the current path of the assembled battery and acquiring a detection signal output from the current sensor to measure the charge / discharge currents of the plurality of cells.
A management method including a step of estimating the state of the assembled battery using the voltage and charge / discharge current measured in the step of measuring.
The battery monitoring system according to any one of claims 1 to 9.
A vehicle including an in-vehicle control device that communicates with the battery monitoring system and acquires predetermined information from the battery monitoring system.