JP2022136746A - battery management system - Google Patents

Abstract

To provide a battery management system that can inhibit omission of data including battery information.SOLUTION: A monitoring device includes a monitoring IC 33 that acquires battery information, and a wireless IC 35. A control device 40 performs wireless communication with the wireless IC 35. The control device 40 transmits request data for requesting transmission of the battery information. The monitoring device 30 transmits response data including the battery information to the control device 40 in response to receiving the request data. The control device 40 makes next request data include communication establishment information of the response data with respect to the request data and transmits the next request data. The wireless IC 35 includes a transmission buffer 350 in which the battery information for a plurality of times can be individually accumulated, and transmits the battery information for one time in the transmission buffer 350 with respect to one piece of the request data. The wireless IC 35 deletes the battery information corresponding to the case of the communication establishment from the transmission buffer 350, and holds the battery information in the transmission buffer 350 in the case of the communication failure.SELECTED DRAWING: Figure 4

Description

The disclosure herein relates to battery management systems.

Patent Literature 1 discloses a battery management system. The contents of the prior art documents are incorporated by reference as descriptions of technical elements in this specification.

Japanese Patent No. 6093448

According to Patent Literature 1, the assembled battery management device determines that wireless communication with the first battery cell management device is impossible when it continuously detects communication errors with the first battery cell management device. Then, the assembled battery management device performs wireless communication with the first battery cell management device via a second battery cell management device different from the first battery cell device. In this way, data including battery information is missing (missing) with the occurrence of a communication failure between the battery cell management device (monitoring device) and the assembled battery management device (control device). In view of the above, or in other aspects not mentioned, there is a need for further improvements in battery management systems.

One object of the disclosure is to provide a battery management system capable of suppressing omission of data including battery information.

The battery management system disclosed herein provides
A monitoring device ( 30) and
A control device (40) that performs wireless communication with a wireless circuit unit and executes predetermined processing based on battery information,
The control device transmits request data requesting transmission of battery information to the monitoring device, and upon receiving the request data, the monitoring device transmits response data including the battery information to the control device,
The control device transmits the next request data including communication establishment information that can distinguish between establishment of communication in which response data is normally received in response to request data and failure in communication in which response data is not normally received. death,
The request data includes a periodic signal transmitted at a predetermined period,
The radio circuit unit includes a transmission buffer (350) capable of individually storing battery information acquired by the monitoring unit for a plurality of times. If the communication is established, the corresponding battery information is deleted from the transmission buffer based on the communication establishment information, and if the communication is not established, the battery information is retained in the transmission buffer.

In the disclosed battery management system, the radio circuitry of the monitoring device includes a transmission buffer. Therefore, battery information for multiple times can be accumulated in the transmission buffer. The battery information accumulated in the transmission buffer is deleted when communication with the control device is established, and is retained in the transmission buffer without being deleted when communication is not established. As a result, loss of data including battery information can be suppressed.

The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. Reference numerals in parentheses described in the claims and this section are intended to exemplify the correspondence with portions of the embodiments described later, and are not intended to limit the technical scope. Objects, features, and advantages disclosed in this specification will become clearer with reference to the following detailed description and accompanying drawings.

1 shows a vehicle with a battery pack; FIG. 1 is a perspective view showing a schematic configuration of a battery pack; FIG. FIG. 3 is a plan view showing an assembled battery; 1 is a block diagram showing the configuration of a battery management system according to a first embodiment; FIG. FIG. 4 is a diagram showing a sequence of battery information requests and responses; 4 is a timing chart showing an example of requests and responses; 4 is a timing chart showing another example of requests and responses; FIG. 10 is a diagram showing an example of a battery information request response sequence in the battery management system according to the second embodiment; 4 is a timing chart showing an example of requests and responses; 4 is a timing chart showing another example of requests and responses; FIG. 12 is a diagram showing data deletion executed by the wireless IC in the battery management system according to the third embodiment; FIG. 10 is a diagram showing another example of data deletion executed by the wireless IC; FIG. 11 is a block diagram showing another configuration example of the battery management system;

A plurality of embodiments will be described below based on the drawings. Note that redundant description may be omitted by assigning the same reference numerals to corresponding components in each embodiment. When only a part of the configuration is described in each embodiment, the configurations of other embodiments previously described can be applied to other portions of the configuration. In addition, not only the combinations of the configurations specified in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined even if they are not specified unless there is a particular problem with the combination. .

(First embodiment)
First, based on FIG. 1, a configuration around a vehicle equipped with a battery management system according to the present embodiment, particularly a battery pack equipped with the battery management system, will be described. FIG. 1 is a diagram showing a schematic configuration of a vehicle. The vehicle is an electric vehicle such as an electric vehicle or a hybrid vehicle.

<Vehicle>
As shown in FIG. 1, the vehicle 10 includes a battery pack (BAT) 11, a PCU 12, an MG 13, and an ECU . PCU is an abbreviation for Power Control Unit. MG is an abbreviation for Motor Generator. ECU is an abbreviation for Electronic Control Unit.

The battery pack 11 includes an assembled battery 20, which will be described later, and provides a chargeable/dischargeable DC voltage source. The battery pack 11 supplies power to electrical loads of the vehicle 10 . Battery pack 11 supplies power to MG 13 through PCU 12 . Battery pack 11 is charged through PCU 12 . Battery pack 11 may be referred to as a main battery.

Battery pack 11 is arranged in a front compartment of vehicle 10, for example, as shown in FIG. The battery pack 11 may be placed in the rear compartment, under the seat, under the floor, or the like. For example, in the case of a hybrid vehicle, the compartment in which the engine is arranged is sometimes called an engine compartment or an engine room.

PCU 12 performs bidirectional power conversion between battery pack 11 and MG 13 according to control signals from ECU 14 . PCU 12 is sometimes referred to as a power converter. PCU 12 includes, for example, an inverter. The inverter converts the DC voltage into an AC voltage, such as a three-phase AC voltage, and outputs the voltage to MG 13 . The inverter converts the power generated by MG 13 into a DC voltage and outputs the DC voltage to the converter. PCU 12 may include a converter. The converter is arranged on the current path between the battery pack 11 and the inverter. The converter has a function of stepping up and down a DC voltage.

The MG 13 is an AC rotary electric machine, for example, a three-phase AC synchronous electric motor in which permanent magnets are embedded in the rotor. The MG 13 functions as a travel drive source for the vehicle 10, that is, as an electric motor. The MG 13 is driven by the PCU 12 to generate rotational driving force. The driving force generated by the MG 13 is transmitted to the driving wheels. The MG 13 functions as a generator during braking of the vehicle 10 and performs regenerative power generation. The power generated by the MG 13 is supplied to the battery pack 11 through the PCU 12 and stored in the assembled battery 20 within the battery pack 11 .

The ECU 14 includes a computer having a processor, a memory, an input/output interface, and a bus connecting them. A processor is hardware for arithmetic processing. A processor includes, for example, a CPU as a core. CPU is an abbreviation for Central Processing Unit. A memory is a non-transitional physical storage medium that non-temporarily stores or stores computer-readable programs and data. The memory stores various programs that are executed by the processor.

ECU 14 acquires information on assembled battery 20 from battery pack 11 , for example, and controls PCU 12 to control driving of MG 13 and charge/discharge of battery pack 11 . The ECU 14 may acquire information such as the voltage, temperature, current, SOC, and SOH of the assembled battery 20 from the battery pack 11 . The ECU 14 may acquire battery information such as the voltage, temperature and current of the assembled battery 20 and calculate the SOC and SOH. SOC is an abbreviation for State Of Charge. SOH is an abbreviation for State Of Health.

The processor of ECU 14 executes a plurality of instructions contained in, for example, a PCU control program stored in memory. Thereby, the ECU 14 constructs a plurality of functional units for controlling the PCU 12 . In the ECU 14, a program stored in the memory causes the processor to execute a plurality of instructions, thereby constructing a plurality of functional units. The ECU 14 is sometimes called an EVECU.

<Battery pack>
Next, an example of the configuration of the battery pack 11 will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a perspective view schematically showing the inside of the battery pack 11. As shown in FIG. In FIG. 2, the housing is indicated by a chain double-dashed line. FIG. 3 is a plan view showing the upper surface of each battery stack.

As shown in FIG. 2 , the battery pack 11 includes an assembled battery 20 , multiple monitoring devices 30 , a control device 40 and a housing 50 . Housing 50 accommodates other elements that make up battery pack 11 , that is, assembled battery 20 , monitoring device 30 , and control device 40 .

Hereinafter, as shown in FIG. 2, of the surfaces of the substantially rectangular parallelepiped housing 50 on which the housing 50 is mounted on the vehicle 10, the longitudinal direction is indicated as the X direction, and the lateral direction is indicated as the Y direction. In FIG. 2, the lower surface is the mounting surface. The vertical direction perpendicular to the mounting surface is indicated as the Z direction. The X direction, Y direction, and Z direction are in a positional relationship orthogonal to each other. In this embodiment, the lateral direction of the vehicle 10 corresponds to the X direction, the longitudinal direction corresponds to the Y direction, and the vertical direction corresponds to the Z direction. The arrangement shown in FIGS. 2 and 3 is merely an example, and battery pack 11 may be arranged in any way with respect to vehicle 10 .

The assembled battery 20 has a plurality of battery stacks 21 arranged side by side in the X direction. The battery stack 21 is sometimes called a battery block or battery module. The assembled battery 20 is configured by connecting a plurality of battery stacks 21 in series. Each battery stack 21 has a plurality of battery cells 22 . The battery stack 21 has a plurality of battery cells 22 connected in series. The battery stack 21 of the present embodiment is configured by connecting in series a plurality of battery cells 22 arranged side by side in the Y direction. The assembled battery 20 provides the DC voltage source described above. The assembled battery 20, the battery stack 21, and the battery cells 22 correspond to batteries.

The battery cell 22 is a secondary battery that generates an electromotive voltage through a chemical reaction. As the secondary battery, for example, a lithium-ion secondary battery or a nickel-hydrogen secondary battery can be employed. A lithium-ion secondary battery is a secondary battery that uses lithium as a charge carrier. A so-called all-solid-state battery using a solid electrolyte can be included in addition to a general lithium-ion secondary battery whose electrolyte is a liquid.

Linear busbar units 23 are arranged at both ends in the X direction on the upper surface of each battery stack 21 . That is, each battery stack 21 is provided with a pair of busbar units 23 . The busbar unit 23 electrically connects the plurality of battery cells 22 . As shown in FIG. 3, each battery cell 22 is formed in a flat shape and stacked so that the side surfaces thereof overlap each other in the Y direction. The battery cell 22 has a positive electrode terminal 25 and a negative electrode terminal 26 protruding in the Z direction, more specifically in the Z+ direction indicating upward, at both ends in the X direction. The battery cells 22 are stacked such that the positive terminals 25 and the negative terminals 26 are alternately arranged in the Y direction.

Each busbar unit 23 has a plurality of busbars 24 electrically connecting the positive terminal 25 and the negative terminal 26 and a busbar cover 27 covering the plurality of busbars 24 . The bus bar 24 is a plate material made of a highly conductive metal such as copper. The busbar 24 electrically connects the positive terminal 25 and the negative terminal 26 of the battery cells 22 adjacent in the Y direction. Thus, in each battery stack 21, the plurality of battery cells 22 are electrically connected in series. In each battery stack 21, the positive electrode terminal 25 of the battery cell 22 arranged on one end side in the Y direction is connected to a predetermined positive electrode wiring, and the negative electrode terminal 26 of the battery cell 22 arranged on the other end side is connected to It is connected to a predetermined negative electrode wiring.

The busbar cover 27 is formed using an electrical insulating material such as resin. The busbar cover 27 is linearly provided from end to end of the battery stack 21 along the Y direction so as to cover the plurality of busbars 24 .

A monitoring device 30 is provided individually for each of the plurality of battery stacks 21 . The monitoring device 30 is arranged between a pair of busbar units 23 in each battery stack 21, as shown in FIG. The monitoring device 30 is fixed to the busbar unit 23 with screws or the like. The monitoring device 30 is configured to be able to wirelessly communicate with the control device 40 as will be described later. An antenna 37, which will be described later, included in the monitoring device 30 is arranged so as not to overlap the busbar unit 23 in the Z direction, that is, so as to protrude beyond the busbar unit 23 in the Z direction.

The control device 40 is attached to the outer side surface of the battery stack 21 arranged at one end in the X direction. The control device 40 is configured to be able to wirelessly communicate with each monitoring device 30 . An antenna 42 , which will be described later, included in the control device 40 is arranged at the same height as the wireless antenna of the monitoring device 30 in the Z direction. That is, the antenna 42 of the control device 40 is provided so as to protrude further than the busbar unit 23 in the Z direction.

In the battery pack 11, the monitoring device 30 and the control device 40 provide a battery management system, which will be described later. That is, the battery pack 11 has a battery management system.

<Battery management system>
Next, based on FIG. 4, a schematic configuration of the battery management system will be described. FIG. 4 is a block diagram showing the configuration of the battery management system.

As shown in FIG. 4 , the battery management system 100 includes multiple management devices (SBM) 30 and a control device (ECU) 40 . SBM is an abbreviation for Satellite Battery Module. Control device 40 is sometimes referred to as a battery ECU or BMU. BMU is an abbreviation for Battery Management Unit. The battery management system 100 is a system that manages batteries using wireless communication. In the battery management system 100 , wireless communication is performed between one control device 40 and multiple monitoring devices 30 .

<Monitoring device>
First, the monitoring device 30 will be described. Since the configuration of each monitoring device 30 is substantially common to each other, the common configuration will be described below. The monitoring device 30 includes a power supply circuit (PSC) 31, a multiplexer (MUX) 32, a monitoring IC (MIC) 33, a microcomputer (MC) 34, a wireless IC (WIC) 35, and a front end circuit (FE) 36. , and an antenna (ANT) 37 . Communication between each element in the monitoring device 30 is performed by wire.

The power supply circuit 31 uses the voltage supplied from the battery stack 21 to generate operating power for other circuit elements included in the monitoring device 30 . In this embodiment, the power supply circuit 31 includes power supply circuits 311 , 312 , and 313 . The power supply circuit 311 generates a predetermined voltage using the voltage supplied from the battery stack 21 and supplies it to the monitoring IC 33 . The power supply circuit 312 generates a predetermined voltage using the voltage generated by the power supply circuit 311 and supplies it to the microcomputer 34 . The power supply circuit 313 generates a predetermined voltage using the voltage generated by the power supply circuit 311 and supplies it to the wireless IC 35 .

The multiplexer 32 is a selection circuit that receives detection signals from a plurality of sensors 60 included in the battery pack 11 and outputs them as one signal. The multiplexer 32 selects (switches) the input according to the selection signal from the monitoring IC 33 and outputs it as one signal. The sensor 60 includes a sensor for detecting the physical quantity of each battery cell 22 and a sensor for determining which battery cell 22 it is. Physical quantity detection sensors include, for example, voltage sensors, temperature sensors, and current sensors.

The monitoring IC 33 senses (obtains) battery information such as cell voltage, cell temperature, and cell discrimination through the multiplexer 32 and transmits the information to the microcomputer 34 . Supervisory IC 33 is sometimes referred to as a cell supervisory circuit (CSC). CSC is an abbreviation for Cell Supervising Circuit. The monitoring IC 33 may have a function of diagnosing a circuit portion of the monitoring device 30 including itself and transmitting the diagnosis result together with the battery information as monitoring data. When the monitoring IC 33 receives data requesting acquisition of battery information transmitted from the microcomputer 34 , the monitoring IC 33 senses battery information through the multiplexer 32 and transmits monitoring data including at least battery information to the microcomputer 34 . The monitoring IC 33 corresponds to a monitoring section.

The microcomputer 34 is a microcomputer having a CPU as a processor, ROM and RAM as memories, an input/output interface, a bus connecting these, and the like. The CPU constructs a plurality of functional units by executing various programs stored in the ROM while using the temporary storage function of the RAM. ROM is an abbreviation for Read Only Memory. RAM is an abbreviation for Random Access Memory.

The microcomputer 34 controls the sensing by the monitoring IC 33 and the schedule of self-diagnosis. The microcomputer 34 receives the monitoring data transmitted from the monitoring IC 33 and transmits it to the wireless IC 35 . The microcomputer 34 transmits data requesting acquisition of battery information to the monitoring IC 33 . As an example, when the microcomputer 34 of the present embodiment receives data requesting acquisition of battery information transmitted from the wireless IC 35 , it transmits data requesting acquisition of battery information to the monitoring IC 33 .

The wireless IC 35 includes an RF circuit for wirelessly transmitting and receiving data. The radio IC 35 may include a microcomputer in addition to the RF circuit. The wireless IC 35 has a transmission function of modulating transmission data and oscillating at the frequency of the RF signal. The wireless IC 35 has a reception function of demodulating received data. RF is an abbreviation for radio frequency.

Wireless IC 35 modulates data including monitoring information transmitted from microcomputer 34 and transmits the modulated data to control device 40 via front-end circuit 36 and antenna 37 . The wireless IC 35 adds data necessary for wireless communication such as communication control information to transmission data including battery information, and transmits the data. Data necessary for wireless communication includes, for example, an identifier (ID) and an error detection code. The wireless IC 35 controls the data size, communication format, schedule, error detection, etc. of communication between the SBM 30 and the control device 40 .

Wireless IC 35 receives data transmitted from control device 40 via antenna 37 and front-end circuit 36 and demodulates it. For example, when wireless IC 35 receives data including a transmission request for battery information, wireless IC 35 transmits data including battery information to control device 40 as a response to the request. As an example, the wireless IC 35 of the present embodiment transmits data (information) related to the acquisition request to the microcomputer 34 when receiving data including the acquisition request for battery information. The radio IC 35 corresponds to a radio circuit section.

The wireless IC 35 has a transmission buffer (BUF) 350 that stores battery information. The transmission buffer 350 temporarily holds monitoring data including battery information. The transmission buffer 350 is configured to be able to accumulate monitoring data for multiple times, that is, battery information acquired multiple times by the monitoring IC 33 . The transmission buffer 350 of this embodiment is a hardware circuit configured within the RF circuit. In a configuration in which the wireless IC 35 includes a microcomputer, the transmission buffer 350 may be configured by software. When the wireless IC 35 receives the communication establishment information transmitted by the control device 40 , the wireless IC 35 deletes the monitoring data for which communication has been established from the transmission buffer 350 .

The front-end circuit 36 has a matching circuit for impedance matching between the radio IC 35 and the antenna 37, and a filter circuit for removing unnecessary frequency components.

The antenna 37 converts an RF signal, which is an electrical signal, into radio waves and radiates them into space. The antenna 37 receives radio waves propagating in space and converts them into electrical signals.

<Control device>
Next, the control device 40 will be explained. The control device 40 includes a power supply circuit (PSC) 41, an antenna (ANT) 42, a front end circuit (FE) 43, a wireless IC (WIC) 44, a main microcomputer (MMC) 45, and a sub-microcomputer (SMC). 46. Communication between each element in the control device 40 is performed by wire.

The power supply circuit 41 uses the voltage supplied from the battery (BAT) 15 to generate operating power for other circuit elements included in the control device 40 . The battery 15 is a DC voltage source separate from the battery pack 11 and mounted on the vehicle 10 . Battery 15 is sometimes referred to as an auxiliary battery because it supplies power to auxiliary equipment of vehicle 10 . In this embodiment, the power supply circuit 41 includes power supply circuits 411 and 412 . The power supply circuit 411 generates a predetermined voltage using the voltage supplied from the battery 15 and supplies it to the main microcomputer 45 and sub-microcomputer 46 . For simplification of the drawing, the electrical connection between the power supply circuit 411 and the sub-microcomputer 46 is omitted. The power supply circuit 412 generates a predetermined voltage using the voltage generated by the power supply circuit 411 and supplies it to the wireless IC 44 .

The antenna 42 converts an RF signal, which is an electrical signal, into radio waves and radiates them into space. The antenna 42 receives radio waves propagating in space and converts them into electrical signals.

The front end circuit 43 has a matching circuit for impedance matching between the wireless IC 44 and the antenna 42, and a filter circuit for removing unnecessary frequency components.

The wireless IC 44 has an RF circuit for wirelessly transmitting and receiving data. The wireless IC 44 has a configuration similar to that of the wireless IC 35 . The wireless IC 44 has a transmission function and a reception function. Wireless IC 44 receives data transmitted from monitoring device 30 via antenna 42 and front-end circuit 43 and demodulates it. Then, it transmits monitoring data including battery information to the main microcomputer 45 . The radio IC 44 receives and modulates data transmitted from the main microcomputer 45 and transmits the data to the monitoring device 30 via the front end circuit 43 and the antenna 42 . The wireless IC 44 adds data necessary for wireless communication such as communication control information to the transmission data, and transmits the data. Data necessary for wireless communication includes, for example, an identifier (ID) and an error detection code. The wireless IC 44 controls the data size, communication format, schedule, error detection, etc. of communication between the monitoring device 30 and the control device 40 .

The main microcomputer 45 is a microcomputer having a CPU, a ROM, a RAM, an input/output interface, and a bus connecting them. The ROM stores various programs executed by the CPU. The main microcomputer 45 generates a command requesting processing from the monitoring device 30 and transmits transmission data including the command to the wireless IC 44 .

The main microcomputer 45 generates a transmission request command requesting transmission of monitoring data including battery information, for example. The main microcomputer 45 can include an acquisition request command requesting acquisition of monitoring data in the transmission data containing the transmission request command. The main microcomputer 45 can include communication establishment information indicating whether or not wireless communication with the monitoring device 30 has been performed normally in the transmission data including the transmission request command.

The main microcomputer 45 receives monitoring data including battery information transmitted from the wireless IC 44 and executes predetermined processing based on the monitoring data. For example, the main microcomputer 45 executes processing for transmitting the acquired battery information to the ECU 14 . The main microcomputer 45 may calculate the SOC and/or SOH based on the battery information, and transmit battery information including the calculated SOC and SOH to the ECU 14 . The main microcomputer 45 may execute equalization processing for equalizing the voltage of each battery cell 22 based on the battery information. The main microcomputer 45 may acquire the IG signal of the vehicle 10 and execute the above-described processing according to the driving state of the vehicle 10 based on the IG signal. The main microcomputer 45 may execute processing for detecting an abnormality in the battery cell 22 based on the battery information, or may transmit abnormality detection information to the ECU 14 .

The sub-microcomputer 46 is a microcomputer having a CPU, a ROM, a RAM, an input/output interface, and a bus connecting them. The ROM stores various programs executed by the CPU. The sub-microcomputer 46 executes monitoring processing within the control device 40 . For example, sub-microcomputer 46 may monitor data between wireless IC 44 and main microcomputer 45 . The sub-microcomputer 46 may monitor the state of the main microcomputer 45 . The sub-microcomputer 46 may monitor the state of the wireless IC 44 .

<Battery information transmission/reception>
Next, transmission and reception of battery information between the control device 40 and one monitoring device 30 will be described with reference to FIG. FIG. 5 shows an example of a battery information request and response sequence. In FIG. 5 , the monitoring IC 33 is indicated as the MIC 33 , the wireless IC 35 as the WIC 35 , and the control device 40 as the ECU 40 .

As shown in FIG. 5, the control device 40 transmits request data including an acquisition request and a transmission request for monitoring data including battery information to the monitoring device 30 (step S10). The transmission data in step S10 corresponds to periodic data transmitted at a predetermined period among the request data. Requests are sometimes referred to as instructions. The request data to be transmitted also includes communication completion information indicating whether or not control device 40 normally received response data including battery information in the previous transmission/reception, that is, in the previous request and response. For example, in the case of the first transmission/reception after the power is turned on, the communication establishment information may be communication failure. Since all the data in the transmission buffer 350 has been deleted by turning off the power, the communication established information may be the communication established.

Upon receiving the request data, the wireless IC 35 of the monitoring device 30 deletes the communication-established data, ie, the previous monitoring data, from the transmission buffer 350 if the communication establishment information indicates that the communication has been established (step S20). Deletion of the previous data is performed only when communication is established. If communication is not established, the previous monitoring data is not deleted from the transmission buffer 350 and is held.

Next, the wireless IC 35 transmits an acquisition request for monitoring data including battery information to the monitoring IC 33 (step S30). In this embodiment, the wireless IC 35 transmits an acquisition request to the monitoring IC 33 via the microcomputer 34 .

Upon receiving the acquisition request, the monitoring IC 33 performs sensing (step S40). The monitoring IC 33 performs sensing and acquires battery information of each battery cell 22 through the multiplexer 32 . Also, the monitoring IC 33 executes failure diagnosis of the circuit.

Then, the monitoring IC 33 transmits monitoring data including battery information to the wireless IC 35 (step S50). In this embodiment, monitoring data including failure diagnosis results is transmitted together with battery information. The monitoring IC 33 transmits to the wireless IC 35 via the microcomputer 34 .

When the wireless IC 35 receives the monitoring data acquired by the monitoring IC 33, the wireless IC 35 accumulates the monitoring data in the transmission buffer 350 (step S60). Then, the wireless IC 35 transmits the transmission data including the one-time monitoring data among the monitoring data accumulated in the transmission buffer 350 to the control device 40 as response data (step S70). The wireless IC 35 transmits the monitoring data accumulated in the transmission buffer 350 in chronological order, for example, in chronological order. If the previous monitoring data is not accumulated in the transmission buffer 350 , the wireless IC 35 transmits the data acquired in step S<b>60 , that is, the currently acquired monitoring data to the control device 40 .

After executing the process of step S10, the control device 40 determines whether communication has been established (step S80). The control device 40 determines whether or not the monitoring data including the battery information is normally received within one transmission/reception cycle, and reflects this determination result in the communication establishment information to be transmitted next time.

The communication establishment information is information capable of distinguishing communication establishment normally received by the control device 40 from communication failure not normally received. Control device 40 determines that communication is not established, for example, when monitoring data including battery information cannot be received within one cycle. The control device 40 may determine that communication is not established when monitoring data cannot be received within a predetermined period of time shorter than one cycle. For example, the control device 40 may include the sequence number in the request data to be transmitted and have the sequence number returned in the response data to perform the time-out check. The control device 40 also determines that communication is not established when a communication error is detected in the inspection performed at the time of reception, even though reception was successful. Control device 40 performs a check using, for example, an error detection code when data is received. The communication establishment information may include information indicating that communication has been established and/or information indicating that communication has not been established. Even if one of the information indicating that communication is established and the information indicating that communication is not established is included, wireless IC 35 can determine whether or not communication was established last time.

The battery management system 100 repeatedly executes the processes of steps S10 to S80 described above at a predetermined cycle.

<Summary of the first embodiment>
According to the battery management system 100 of this embodiment, the wireless IC 35 of the monitoring device 30 includes the transmission buffer 350 . The transmission buffer 350 can accumulate monitoring data for multiple times by the monitoring IC 33 of the monitoring device 30, that is, battery information for multiple times. The monitoring data accumulated in the transmission buffer 350 is deleted when the communication with the control device 40 is normally performed according to the communication establishment information from the control device 40 . On the other hand, if communication is not successful, the monitoring data is retained in the transmission buffer 350 without being deleted and is retransmitted. As a result, loss of data including battery information can be suppressed.

In the case of wireless communication, the communication speed is slower than that of wired communication, and the frequency of communication is often low. Therefore, if an abnormality occurs in at least one of the physical quantities such as the voltage of the battery cell 22, or if an abnormality is detected by the failure diagnosis information, and if monitoring data is missing, the value may change rapidly. have a nature. If the value is abruptly changed, the control will be abruptly changed, and although there is no problem with safety, there is a possibility that operability will be affected. On the other hand, according to the present embodiment, it is possible to suppress omission of monitoring data indicating an abnormality. Thereby, the influence on operability can be suppressed.

In addition, by suppressing omission of monitoring data, it is possible to accurately estimate an element to be estimated by accumulating monitoring data, such as accumulation of battery damage. In addition, there are cases where abnormality detection is performed based on the number of times the threshold is exceeded. In this case as well, it is possible to advance the detection timing of an abnormality by suppressing omission of monitoring data.

6 and 7 are timing charts showing examples of transmission and reception, that is, requests and responses, in the battery management system 100 according to this embodiment. FIG. 6 shows an example in which transmission and reception are normally performed over a plurality of cycles. FIG. 7 shows an example of a case where transmission/reception is not normal.

Each of T1, T2, and T3 shown in FIGS. 6 and 7 indicates one transmission/reception cycle. TxA indicates request data transmitted from the control device 40 to the monitoring device 30 . TxA corresponds to periodic data. Rx indicates monitoring data among response data transmitted from the monitoring device 30 to the control device 40 . The number appended to Rx indicates the number of times (cycle) the monitoring IC 33 acquired the monitoring data. For example, Rx1 is monitoring data acquired in the first cycle T1. In the following, it is assumed that monitoring data is not accumulated in the transmission buffer 350 at the stage of executing the processing of the first cycle T1.

When the communication is normally performed, the previous monitoring data accumulated in the transmission buffer 350 is deleted according to the communication establishment information included in the data TxA. Therefore, as shown in FIG. 6, if the communication establishment continues, the acquired monitoring data can be transmitted to the control device 40 as a response signal within the cycle. That is, it is possible to transmit the monitoring data including the acquired latest battery information to the control device 40 . The control device 40 can execute processing based on the latest monitoring data.

In the example shown in FIG. 7, the control device 40 cannot normally receive the data Rx1 in the first period T1. Therefore, in the second cycle T2, the communication establishment information included in the data TxA indicates that the communication is not established. As a result, the data Rx1 in the transmission buffer 350 is held and transmitted as response data in the second cycle T2. The data Rx2 acquired in the second period T2 is held in the transmission buffer 350 without being transmitted in the second period T2. In the second period T2, control device 40 normally receives data Rx1. Therefore, data Rx2 is transmitted in the third period T3. In this way, data for which communication has not been established can be retransmitted without deleting the data. That is, loss of data including battery information can be suppressed.

In this embodiment, the control device 40 requests acquisition and transmission of monitoring data including battery information, and the monitoring IC 33 acquires and transmits the monitoring data accordingly. This eliminates the need for the monitoring IC 33 to manage and grasp the communication schedule. In addition, centralized management of the communication schedule by the control device 40 makes it possible to easily manage and change the communication schedule. Also, the control in the monitor IC 33 can be simplified.

In this embodiment, the example in which the monitoring data acquired by the monitoring IC 33 is stored in the transmission buffer 350 after deleting the previous data of communication establishment from the transmission buffer 350 is shown. However, after accumulating the acquired monitoring data in the transmission buffer 350 , the previous data of communication establishment may be deleted from the transmission buffer 350 . Prior to executing the data transmission process in step S70, it is only necessary to delete the previous data when communication was established and accumulate the monitoring data acquired this time.

(Second embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, an example was shown in which the process of requesting and responding to monitoring data is executed only once per cycle. Alternatively, request and response processing may be performed multiple times according to the accumulated data in transmission buffer 350 .

FIG. 8 shows an example of a battery information request and response sequence in the battery management system 100 according to this embodiment. FIG. 8 corresponds to FIG. The processing up to step S60 is the same as in the preceding embodiment. Therefore, description of steps S10 to S50 is omitted, and steps S60 and thereafter are illustrated.

As shown in FIG. 8, the wireless IC 35 executes the process of step S60, that is, the process of accumulating the monitoring data acquired by the monitoring IC 33 in the transmission buffer 350, and then executes the process of step S70A. In step S70A, in place of the processing of step S70 described in the preceding embodiment, together with the one-time monitoring data accumulated in the transmission buffer 350, unsent accumulation information is transmitted. The unsent accumulated information is monitoring data different from the monitoring data transmitted in step S70A, which is accumulated in the transmission buffer 350, and is information relating to the monitoring data not yet transmitted in this transmission/reception cycle. For example, it may be the number of unsent monitoring data or an identifier identifying unsent monitoring data. The battery information included in the monitoring data transmitted in the process of step S70A corresponds to the first battery information. The battery information included in the unsent monitoring data corresponds to the second battery information.

After execution of step S70A, the control device 40 executes the processing of step S80, that is, determination of establishment of communication, as in the preceding embodiment.

The control device 40 determines additional transmission processing based on the untransmitted accumulated information in the received response data (step S90). Control device 40 determines whether additional transmission/reception processing is possible, for example, based on the presence or absence of unsent data and the remaining time of the transmission/reception cycle. If it is determined that it is impossible, the process of step S100 is not executed, and the process from step S10 is executed in the next cycle.

In step S100, the control device 40 executes the process excluding the monitoring data acquisition request from the process of step S10. In other words, it transmits request data including a transmission request for monitoring data and communication establishment information. Note that the request data transmitted in the process of step S10 corresponds to the first request data. The request data transmitted in step S100 corresponds to the second request data.

Upon receiving the request data processed in step S100, wireless IC 35 of monitoring device 30 executes the process of step S110. Step S110 is the same process as step S20. In step S<b>110 , the wireless IC 35 deletes from the transmission buffer 350 the previous monitoring data when the communication is established when the communication establishment information indicates that the communication is established.

Since the received request data does not include an acquisition request, the additional transmission/reception processing does not perform the same processing as steps S30 to S60. After completing the process of step S110, the wireless IC 35 executes the process of step S120. Step S120 is the same process as step S70A.

After executing step S120, control device 40 executes the process of step S130 and the process of step S140. Step S130 is the same process as step S80, and step S140 is the same process as step S90. The processing enclosed by the two-dot chain line shown in FIG. 8, that is, the processing of steps S100 to S140 is the additional transmission/reception processing. In step S140, when control device 40 determines that additional transmission/reception processing is possible, control device 40 executes additional transmission/reception processing again. In this way, when there is unsent monitoring data in the transmission buffer 350 and transmission/reception within the period is possible, additional transmission/reception processing is repeatedly executed.

The wireless IC 35 may perform flag management of the transmission buffer 350 in the above-described processing, for example. The flag is set to 1 when the monitoring data accumulated in the transmission buffer is processed for transmission. If communication is established in this state, the corresponding monitoring data is deleted from the transmission buffer 350 . On the other hand, if the communication is not established, the flag for the corresponding monitoring data is reset to 0. As a result, when communication is not established, the monitoring data is retained without being deleted. This approach can be applied to previous embodiments.

When a plurality of pieces of monitoring data are accumulated, the transmission buffer 350 performs processing for transmitting the monitoring data, for example, in order of acquisition. The transmission buffer 350 shifts the operation position by one when performing additional transmission (step S120) within one cycle. As described above, in one cycle, when the first transmitted monitoring data fails to establish communication, the monitoring data can be held without being deleted, and another monitoring data can be transmitted.

<Summary of Second Embodiment>
In this embodiment, when the wireless IC 35 transmits the monitoring data (battery information) accumulated in the transmission buffer 350 in response to the request data (first request data) from the control device 40, the battery information (first request data) to be transmitted. battery information), and the accumulated information of the untransmitted battery information (second battery information) is included in the response data and transmitted. When the control device 40 receives the response data including the accumulated information, the control device 40 transmits request data (second request data) requesting transmission of the untransmitted battery information to the monitoring device 30 within the same period as the first request data. do. That is, when there is remaining data in the transmission buffer 350, additional transmission/reception processing is executed. As a result, it is possible to prevent the transmission of the latest monitoring data from being delayed while suppressing omission of monitoring data as in the preceding embodiment.

For example, it is preferable to use the latest battery information for charge/discharge control of assembled battery 20 and control of PCU 12 and MG 13 . According to the present embodiment, it is possible to improve the accuracy of estimating the accumulation of battery damage, which is affected by lack of monitoring data, and to improve the accuracy of various controls for which the latest monitoring data are important.

9 and 10 are timing charts showing examples of requests and responses in the battery management system 100 according to this embodiment. 9 and 10 correspond to FIGS. 6 and 7 described above. TxA indicates the first requested data, and TxB indicates the second requested data (additional requested data). TxA corresponds to periodic data. Here, too, it is assumed that data is not accumulated in the transmission buffer 350 at the stage of executing the processing of the first cycle T1.

FIG. 9 shows an example in which the control device 40 cannot receive the data Rx1 transmitted by the monitoring device 30 in the first period T1. The control device 40 cannot receive unstored information. In the second period T2, the communication establishment information included in the data TxA indicates that communication is not established. Therefore, upon receiving the data TxA, the monitoring device 30 holds the data Rx1 accumulated in the transmission buffer 350 without deleting it. The monitoring device 30 transmits data Rx1 from the transmission buffer 350 as response data for the second cycle T2. The data Rx2 acquired in the second cycle T2 is held in the transmission buffer 350 without being transmitted. Therefore, the response signal includes data Rx1 and unsent stored information indicating that there is unsent data.

In the second period T2, control device 40 normally receives data Rx1. Since there is unsent monitoring data, the control device 40 transmits data TxB including an additional transmission request. When the data TxB is received, the monitoring device 30 deletes the data Rx1 accumulated in the transmission buffer 350 based on the communication establishment information included in the data TxB. Also, data Rx2 is transmitted from the transmission buffer 350 . The response signal includes data Rx2 and unsent storage information indicating no unsent data.

In the second period T2, control device 40 normally receives data Rx2. Since there is no unsent data, control device 40 does not execute additional transmission requests. In the third period T3, the communication establishment information included in the data TxA indicates establishment of communication of the data Rx2. Upon receiving the data TxA, the monitoring device 30 deletes the data Rx2 accumulated in the transmission buffer 350 based on the communication establishment information. Also, it transmits the acquired data Rx3 from the transmission buffer 350 .

FIG. 10 shows an example in which the control device 40 fails to operate the control device 40 in the first period T1 and detects a communication error by checking the data RX1 in the second period T2. The flow until the monitoring device 30 retransmits the data Rx1 in the second period T2 is the same as that in FIG. 9, and thus the description is omitted. The data Rx1 is transmitted with untransmitted storage information indicating that there is untransmitted data.

In the second period T2, the control device 40 receives the data Rx1, but detects a communication error by inspection using an error correction code or the like. Since there is unsent data, the control device 40 transmits data TxB including an additional transmission request. Data TxB includes communication establishment information indicating that communication is not established. Upon receiving the data TxB, the monitoring device 30 retains the data Rx1 accumulated in the transmission buffer 350 without deleting based on the communication establishment information included in the data TxB. Also, data Rx2 is transmitted from the transmission buffer 350 . The response signal includes data Rx2 and unsent storage information indicating no unsent data.

In the second period T2, control device 40 normally receives data Rx2. Since there is no unsent data, control device 40 does not execute additional transmission requests. In the third period T3, the communication establishment information included in the data TxA indicates establishment of communication of the data Rx2. Upon receiving the data TxA, the monitoring device 30 deletes the data Rx2 accumulated in the transmission buffer 350 based on the communication establishment information. The monitoring device 30 transmits data Rx1 from the transmission buffer 350 as response data for the third cycle T3. The data Rx3 acquired in the third cycle T3 is held in the transmission buffer 350 without being transmitted. The response signal includes data Rx1 and unsent stored information indicating that there is unsent data.

In the third period T3, control device 40 normally receives data Rx1. Since there is unsent data, the control device 40 transmits data TxB including an additional transmission request. When the data TxB is received, the monitoring device 30 deletes the data Rx1 accumulated in the transmission buffer 350 based on the communication establishment information included in the data TxB. Also, data Rx3 is transmitted from the transmission buffer 350 . The response signal includes data Rx3 and unsent stored information indicating no unsent data.

As can be seen from the examples shown in FIGS. 9 and 10, according to the present embodiment, it is possible to prevent the transmission of the latest monitoring data from being delayed while suppressing omission of monitoring data.

(Third embodiment)
This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used. Although not specifically mentioned in the preceding embodiment, all data accumulated in the transmission buffer 350 may be deleted when a predetermined condition is met.

FIG. 11 is a diagram showing processing executed by the wireless IC 35 in the battery management system 100 according to this embodiment. The wireless IC 35 deletes all the monitoring data in the transmission buffer 350 when the transmission buffer 350 is full, that is, when the new monitoring data acquired by the monitoring IC 33 cannot be stored in the transmission buffer 350 . In other words, it returns to the initial state in which monitoring data is not accumulated. As a result, newly acquired monitoring data (dataG) can be accumulated in the transmission buffer 350 .

The wireless IC 35 may determine whether or not there is space based on the accumulated information of the monitoring data in the transmission buffer 350 , and collectively delete all the data in the transmission buffer 350 if it determines that there is no space. For example, all data may be deleted by hardware processing such as power-on reset. Reset processing may be executed on software to delete all data.

Alternatively, the connection establishment state between the monitoring device 30 and the control device 40 may be canceled, and all data may be deleted along with this cancellation. In this case, connection establishment work such as so-called pairing is required again. Alternatively, the control device 40 may determine the availability of the transmission buffer 350 and transmit an instruction to delete all the data accumulated in the transmission buffer 350 to the monitoring device 30 . The monitoring device 30 collectively deletes all the data in the transmission buffer 350 when receiving the instruction to delete all the data. Control device 40 may determine the availability of transmission buffer 350 based on, for example, unsent accumulated information and communication establishment information.

<Summary of Third Embodiment>
As described above, in this embodiment, the wireless IC 35 deletes all monitoring data in the transmission buffer 350 when the transmission buffer 350 is full. Therefore, when the communication environment between the monitoring device 30 and the control device 40 deteriorates and the communication is abnormal, that is, the communication failure continues, it is possible to prevent newly acquired monitoring data from being unable to be transmitted. For example, in a configuration that executes additional transmission/reception processing, it is possible to prevent newly acquired monitoring data from being unable to be transmitted within the acquired cycle.

<Modification>
The timing of deleting all the data accumulated in the transmission buffer 350 is not limited to the state where the transmission buffer 350 is full. For example, the number of data that can be transmitted in one transmission/reception cycle may be less than the number of data that can be accumulated in the transmission buffer 350 . In such a case, the wireless IC 35 may delete all the data accumulated in the transmission buffer 350 when the data that can be transmitted within one cycle is exceeded.

For example, when the number of data that can be transmitted from the monitoring device 30 in one cycle is three, three pieces of monitoring data are accumulated in the transmission buffer 350 as shown in FIG. Since four pieces of monitoring data are accumulated including newly obtained monitoring data, the wireless IC 35 deletes all the monitoring data in the transmission buffer 350 . As a result, newly acquired monitoring data (dataG) can be accumulated in the transmission buffer 350 .

The deletion of all data shown in the third embodiment and its modification can be combined with any of the preceding embodiments.

(Other embodiments)
The disclosure in this specification, drawings, etc. is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations thereon by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and/or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses omitting parts and/or elements of the embodiments. The disclosure encompasses permutations or combinations of parts and/or elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is indicated by the description of the claims, and should be understood to include all changes within the meaning and range of equivalents to the description of the claims.

The disclosure in the specification, drawings, etc. is not limited by the description in the claims. The disclosure in the specification, drawings, etc. encompasses the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure of the specification, drawings, etc., without being bound by the scope of claims.

When an element or layer is referred to as being "overlying," "coupled with," "connected to," or "coupled with," it refers to other elements or layers. may be coupled, connected or bonded directly on, and there may be intervening elements or layers. In contrast, an element is "directly on", "directly coupled to", "directly connected to" or "directly coupled to" another element or layer. When referred to, there are no intervening elements or layers present. Other terms used to describe relationships between elements are used in a similar fashion (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). ) should be interpreted. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The spatially relative terms "inside", "outside", "behind", "below", "low", "above", "high", etc., refer to an element or feature as illustrated. It is used here to facilitate the description describing its relationship to other elements or features. Spatially-relative terms can be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, when the device in the figures is turned over, elements described as "below" or "beneath" other elements or features are oriented "above" the other elements or features. Thus, the term "bottom" can encompass both an orientation of up and down. The device may be oriented in other directions (rotated 90 degrees or other orientations) and the spatially relative descriptors used herein interpreted accordingly. .

The apparatus, systems, and techniques described in this disclosure may be implemented by a special purpose computer comprising a processor programmed to perform one or more functions embodied by the computer program. The apparatus and techniques described in this disclosure may also be implemented using dedicated hardware logic. Additionally, the apparatus and techniques described in this disclosure may be implemented by one or more special purpose computers configured in combination with a processor executing a computer program and one or more hardware logic circuits. The computer program may also be stored as computer-executable instructions on a computer-readable non-transitional tangible recording medium. In other words, means and/or functions provided by a processor or the like can be provided by software recorded in a physical memory device and a computer executing the software, only software, only hardware, or a combination thereof. For example, some or all of the functions provided by the processor may be implemented as hardware. A mode of implementing a certain function as hardware includes a mode of implementing it using one or more ICs. The processor may be implemented using MPU, GPU, or DFP instead of CPU. The processor may be implemented by combining multiple types of arithmetic processing units such as CPU, MPU, and GPU. A processor may be implemented as a system-on-chip (SoC). Furthermore, various processing units may be implemented using FPGAs or ASICs. Various programs may be stored in a non-transitional substantive recording medium. Various storage media such as HDD, SSD, flash memory, and SD card can be used as program storage media. DFP is an abbreviation for Data Flow Processor. SoC is an abbreviation for System on Chip. FPGA is an abbreviation for Field Programmable Gate Array. ASIC is an abbreviation for Application Specific Integrated Circuit. HDD is an abbreviation for Hard disk Drive. SSD is an abbreviation for Solid State Drive. SD is an abbreviation for Secure Digital.

For example, although an example in which the monitoring device 30 includes the microcomputer 34 has been shown, the present invention is not limited to this. As shown in FIG. 13, a battery management system 100 in which the monitoring device 30 does not include the microcomputer 34 may be adopted. FIG. 13 corresponds to FIG. In this configuration, the wireless IC 35 transmits and receives data to and from the monitoring IC 33 . The wireless IC 35 or the main microcomputer 45 of the control device 40 may perform the sensing and self-diagnosis schedule control by the monitoring IC 33 .

Although the periodic data (TxA) as the request data periodically transmitted by the control device 40 includes an acquisition request and a transmission request for monitoring data including battery information, the present invention is not limited to this. The periodic data may not include the monitoring data acquisition request, but may include only the monitoring data transmission request. The monitoring device 30 may acquire monitoring data at a predetermined cycle preset according to the transmission/reception cycle, instead of using the acquisition request from the control device 40 as a trigger to acquire new monitoring data. The predetermined cycle corresponds to, for example, one transmission/reception cycle.

Although an example in which the monitoring device 30 is arranged for each battery stack 21 has been shown, the present invention is not limited to this. For example, one monitoring device 30 may be arranged for a plurality of battery stacks 21 . A plurality of monitoring devices 30 may be arranged for one battery stack 21 .

Although an example in which the battery pack 11 includes one control device 40 is shown, the present invention is not limited to this. A plurality of controllers 40 may be provided. That is, the battery pack 11 may include one or more monitoring devices 30 and one or more control devices 40 . The battery management system 100 may include multiple sets of wireless communication systems constructed between one control device 40 and one or more monitoring devices 30 .

Although an example in which the monitoring device 30 includes one monitoring IC 33 is shown, the present invention is not limited to this. A plurality of monitor ICs 33 may be provided. In this case, a wireless IC 35 may be provided for each monitoring IC 33 , or one wireless IC 35 may be provided for a plurality of monitoring ICs 33 .

The arrangement and the number of the battery stacks 21 and the battery cells 22 that constitute the assembled battery 20 are not limited to the above examples. In battery pack 11, the arrangement of monitoring device 30 and/or control device 40 is not limited to the above example.

DESCRIPTION OF SYMBOLS 10... Vehicle, 11... Battery pack, 12... PCU, 13... MG, 14... ECU, 15... Battery, 20... Assembled battery, 21... Battery stack, 22... Battery cell, 23... Bus bar unit, 24... Bus bar, 25 Positive terminal 26 Negative terminal 27 Busbar cover 30 Monitoring device 31, 311, 312, 313 Power supply circuit 32 Multiplexer 33 Monitoring IC 34 Microcomputer 35 Wireless IC 350 Transmission buffer 36 Front end circuit 37 Antenna 40 Control device 41, 411, 412 Power supply circuit 42 Antenna 43 Front end circuit 44 Wireless IC 45 Main microcomputer 46 Sub Microcomputer 50 Housing 60 Sensor 100 Battery management system

Claims (7)

A monitoring device comprising: a monitoring unit (33) for acquiring and monitoring battery information indicating the state of a battery; and a radio circuit unit (35) capable of transmitting and receiving data to and from the monitoring unit and executing wireless communication. (30) and
A control device (40) that performs wireless communication with the wireless circuit unit and executes predetermined processing based on the battery information,
The control device transmits request data requesting transmission of the battery information to the monitoring device, and upon receiving the request data, the monitoring device transmits response data including the battery information to the control device. death,
The control device includes communication establishment information capable of distinguishing communication establishment in which the response data is normally received in response to the request data and communication failure in which the response data is not normally received. send request data,
The request data includes periodic data transmitted in a predetermined period,
The radio circuit unit includes a transmission buffer (350) capable of individually accumulating the battery information acquired by the monitoring unit for a plurality of times. The battery information is transmitted to the control device, the battery information corresponding to the communication establishment is deleted from the transmission buffer based on the communication establishment information, and the battery information is retained in the transmission buffer when the communication is not established. , battery management system. When transmitting the battery information in the transmission buffer in response to the first request data, the radio circuit unit is separate from the first battery information, which is the battery information to be transmitted, and has not yet been transmitted. including accumulated information of the transmitted second battery information in the response data and transmitting the response data to the control device;
When receiving information in which the second battery information is accumulated, the control device transmits second request data requesting transmission of the second battery information within the same cycle as the first request data. 2. The battery management system according to claim 1, which is transmitted as data to said monitoring device. When the control device normally receives the response data including the first battery information in response to the first request data, the control device transmits the second request data including information indicating establishment of communication to the monitoring device,
Upon receiving the second request data, the radio circuit unit deletes the first battery information with which communication has been established from the transmission buffer, and transmits the second battery information in the transmission buffer to the control device. 3. The battery management system according to claim 2, wherein: When the control device receives the response data including the first battery information in response to the first request data but a reception error occurs, the control device receives the second request data without including information indicating establishment of communication. to the monitoring device;
When receiving the second request data, the radio circuit unit transmits the second battery information in the transmission buffer to the control device while holding the first battery information without deleting it from the transmission buffer. 3. The battery management system according to claim 2, wherein: 5. The battery management system according to any one of claims 1 to 4, wherein said wireless circuit unit deletes all data in said transmission buffer when said transmission buffer is full. 5. The battery management system according to any one of claims 1 to 4, wherein said radio circuit unit deletes all the data accumulated in said transmission buffer when the data exceeds the data that can be transmitted within one cycle. The periodic data requests the monitoring device to acquire and transmit the battery information,
The battery management system according to any one of claims 1 to 6, wherein said monitoring unit acquires said battery information in response to said acquisition request.

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