Battery monitoring device and battery monitoring method

Abstract

A battery monitoring device and a battery monitoring method are provided. The battery monitoring device includes: a plurality of charge state acquisition units provided for a plurality of battery modules, respectively, which acquire charge information of the plurality of battery modules, which mutually perform wireless communication and can form an information transmission path of the charge information; a monitoring unit which monitors the plurality of battery modules based on the charge information input via the information transmission path; and a path selection unit which, according to the charge information, selects, for each of the plurality of charge state acquisition units, a charge state acquisition unit which forms the information transmission path to the monitoring unit.

Description

Technical Field

[0001] This invention relates to a battery monitoring device and a battery monitoring method. This application claims priority to Japanese Patent Application No. 2020-195419, filed on November 25, 2020, the contents of which are incorporated herein by reference. Background Technology

[0002] For example, Japanese Patent Application Publication No. 2020-53176 discloses a battery monitoring system that transmits detection results from a voltage detection unit connected to the battery module to a master unit connected to a central monitoring unit via wireless communication from a slave unit located alongside the battery module. In this battery monitoring system, wireless communication is performed using power from the battery module. On the other hand, Japanese Patent Application Publication No. 2019-126018 discloses a structure in which multiple wireless communication terminals mounted in a vehicle communicate wirelessly with each other, thereby forming a mesh network.

[0003] The vehicle is equipped with multiple battery modules, and a voltage detection device is provided for each battery module. Therefore, it is also possible to consider enabling the voltage detection devices to communicate wirelessly with each other, forming a network that includes a monitoring unit, thereby transmitting the status of the battery modules to the monitoring unit.

[0004] However, in the case of a mesh network, information is typically transmitted to the monitoring unit via the path with the best communication status, without considering the charging status of the battery modules. Therefore, there is a possibility that the path used in communication may be off, and the power consumption of battery modules on the path may be higher than that of battery modules not on the path. Consequently, discrepancies may arise in the charging levels of multiple battery modules. Summary of the Invention

[0005] The present invention was made in view of the above-mentioned problems, and its object is to enable the formation of an information transmission path based on the charging state of the battery module in a battery monitoring device and battery monitoring method that transmits information of the battery module to a monitoring unit by forming a grid network.

[0006] The present invention employs the following methods as a means to solve the above-mentioned problems.

[0007] The battery monitoring device according to the first method includes: a plurality of charging status acquisition units, each configured for a plurality of battery modules, acquiring charging information of the plurality of battery modules, communicating wirelessly with each other, and forming an information transmission path for the charging information; a monitoring unit, monitoring the plurality of battery modules based on the charging information input via the information transmission path; and a path selection unit, selecting, for each of the plurality of charging status acquisition units, the charging status acquisition unit forming the information transmission path to the monitoring unit, according to the charging information.

[0008] According to the battery monitoring device of the first aspect, in the second aspect of the present invention, the path selection unit selects the charging state acquisition unit that forms the information transmission path by removing the charging state acquisition unit connected to the charging state acquisition unit of the plurality of battery modules connected to the charging state acquisition unit that forms the information transmission path, and the charging state acquisition unit connected to the battery module whose charging amount is lower than a preset threshold.

[0009] According to the battery monitoring device of the first or second method, in the third method of the present invention, the path selection unit selects the charging state acquisition unit that forms the information transmission path in such a way that the number of the charging state acquisition units that form the information transmission path is less than or equal to a predetermined upper limit number.

[0010] According to any one of the first to third embodiments of the battery monitoring device, in the fourth embodiment of the present invention, when there is a battery module among the plurality of battery modules connected to the charging state acquisition unit that forms the information transmission path whose charging amount is lower than a preset threshold, the monitoring unit reduces the communication frequency of the wireless communication via the information transmission path compared to the case where the charging amount of the battery module is higher than the preset threshold.

[0011] According to any one of the first to fourth embodiments of the battery monitoring device, in the fifth embodiment of the present invention, before the path selection unit selects the charging state acquisition unit that forms the information transmission path based on the charging information, the path selection unit selects the charging state acquisition unit that forms the information transmission path based on the electric field strength of the wireless communication of the plurality of charging state acquisition units that can form the information transmission path.

[0012] The battery monitoring method according to the sixth aspect of the present invention forms an information transmission path from each of the multiple charging state acquisition units respectively provided for multiple battery modules to a monitoring unit that monitors the multiple battery modules through mutual wireless communication. The battery monitoring method includes: acquiring charging information of the multiple battery modules; and, based on the charging information, selecting the charging state acquisition unit that forms the information transmission path for each of the multiple charging state acquisition units.

[0013] In this invention, charging state acquisition units communicate wirelessly with each other, forming a network connecting each charging state acquisition unit and a monitoring unit. Furthermore, in this invention, charging state acquisition units are selected to form information transmission paths from each charging state acquisition unit to the monitoring unit based on the charging state of the battery module acquired by the charging state acquisition units. That is, according to this invention, the information transmission path can be formed taking into account the charging state of the battery module. For example, the information transmission path can be formed in a way that prevents deviations in the charging amount of the battery module. Thus, according to this invention, in a battery monitoring apparatus and battery monitoring method that transmits battery module information to a monitoring unit through a mesh network, the information transmission path can be formed based on the charging state of the battery module. Attached Figure Description

[0014] Figure 1 This is a block diagram illustrating the schematic structure of the battery monitoring system in the first embodiment of the present invention.

[0015] Figure 2 This is a detailed block diagram of the voltage detection device and monitoring device included in the battery monitoring system of the first embodiment of the present invention.

[0016] Figure 3 This is a flowchart illustrating the selection of the information transmission path in the battery monitoring system according to the first embodiment of the present invention.

[0017] Figure 4A It is a schematic conceptual diagram used to illustrate the first path.

[0018] Figure 4B This is a schematic conceptual diagram used to illustrate the second path.

[0019] Figure 5 This is a detailed block diagram of the voltage detection device and monitoring device included in the battery monitoring system according to the second embodiment of the present invention.

[0020] Figure 6 This is a detailed block diagram of the voltage detection device and monitoring device included in the battery monitoring system according to the third embodiment of the present invention. Detailed Implementation

[0021] Hereinafter, with reference to the accompanying drawings, one embodiment of the battery monitoring device and battery monitoring method according to the present invention will be described.

[0022] (First Implementation)

[0023] Figure 1This is a block diagram showing the general structure of the battery monitoring system (battery monitoring device) according to the first embodiment. As shown in the figure, the battery monitoring system of this embodiment includes multiple voltage detection devices A1 to An (charging state acquisition units) and a single monitoring device B (monitoring unit). These voltage detection devices A1 to An and the monitoring device B are freely and wirelessly connected to each other via a predetermined wireless line. Furthermore, in this embodiment, "n" is a subscript word representing any natural number.

[0024] The battery monitoring system monitors a battery pack C consisting of n battery modules M1 to Mn. Each of the n battery modules M1 to Mn has multiple (m) battery cells connected in series, and the total voltage of each battery cell is used as the output voltage. These n battery modules M1 to Mn are connected in series. In other words, the battery pack C monitored in this embodiment is a secondary battery that uses the total voltage of the n battery modules M1 to Mn, i.e., the total voltage of n×m battery cells, as its output voltage.

[0025] In this embodiment, the battery pack C is installed in electric vehicles such as electric cars and hybrid vehicles, for example, to supply DC power to the driving motor (load) that serves as the driving power source. Such a battery pack C is, for example, a lithium-ion battery or a fuel cell, outputting an output voltage of several hundred volts.

[0026] Multiple voltage detection devices A1 to An are configured corresponding to n battery modules M1 to Mn. That is, multiple (n) voltage detection devices A1 to An are configured one-to-one with multiple (n) battery modules M1 to Mn. These voltage detection devices A1 to An form a mesh network with the monitoring device B through wireless communication, detecting the voltage (voltage of each unit) of their respective battery modules M1 to Mn, and wirelessly transmitting the detected voltage value (voltage information) along with their own identification number to the monitoring device B via the mesh network.

[0027] Furthermore, the output voltage of battery modules M1 to Mn varies according to their charge level. The charge level of each battery module M1 to Mn is calculated as SOC (State of Charge) based on the voltage information (charging information) obtained by voltage detection devices A1 to An, for example, in monitoring device B. In other words, the charge level of battery modules M1 to Mn is calculated by monitoring device B, and the voltage information (charging information) representing the charge level is obtained and output by each voltage detection device A1 to An.

[0028] A single monitoring device B monitors the state of battery pack C based on the unit voltage detection values ​​of each battery module M1 to Mn wirelessly received from each voltage detection device A1 to An. This monitoring device B reports the monitoring results of battery pack C sequentially to a higher-level control device (not shown).

[0029] Reference Figure 2 The voltage detection devices A1 to An and the monitoring device B will be described in further detail below. Furthermore, each of the n voltage detection devices A1 to An has a unique identification number for its own designation, but the basic structure of all n voltage detection devices A1 to An is the same. Therefore, the detailed structure of the first voltage detection device A1 will be described below as an example.

[0030] Figure 2 This is a detailed block diagram of the voltage detection device and monitoring device included in the battery monitoring system of this embodiment. As shown in the figure, the first voltage detection device A1 includes a voltage detection unit 1, a plurality of (m) discharge units 2, a storage unit 3, an equalization processing unit 4, a command receiving unit 5, an electric field strength detection unit 6, a data transmission unit 7, and a data receiving unit 8.

[0031] The voltage detection unit 1 is the main functional unit of the first voltage detection device A1. It detects the output voltage (cell voltage) of the m battery cells constituting the first battery module M1 and outputs the detected values ​​(cell voltage detection values) of the m cell voltages to the storage unit 3. Furthermore, as shown in the figure, the electrodes (positive electrode and negative electrode) of each battery cell in the first battery module M1 are respectively connected to the multiple input terminals of the voltage detection unit 1. The voltage detection unit 1 obtains the cell voltage detection value of each battery cell based on the difference between the potential of the positive electrode and the potential of the negative electrode of each battery cell.

[0032] The voltage detection unit 1 detects the cell voltage as an analog value by sampling the potential of the positive electrode and the potential of the negative electrode of each battery cell at predetermined time intervals. Furthermore, the voltage detection unit 1 converts the cell voltage of each battery cell into a digital value with a predetermined resolution, and sequentially outputs the cell voltage as the digital value to the storage unit 3 as the cell voltage detection value.

[0033] As described above, the n battery modules M1 to Mn are secondary batteries capable of discharging and charging. Multiple (m) discharge units 2 are provided for each battery cell to ensure equal charging states among the m battery cells in the first battery module M1. The multiple (m) discharge units 2 are series circuits of electronic switches and resistors.

[0034] These discharge sections 2 consist of electronic switches, such as switching transistors, which are operated to an ON (on) state and an OFF (off) state via an equalization processing section 4, and resistors connected in series with these electronic switches and having a predetermined resistance value. In the electronic switches of the discharge section 2 corresponding to each battery cell, the equalization processing section 4 sets an ON state and an OFF state to equalize the charging states of the m battery cells (the m battery cells).

[0035] Storage unit 3 stores the cell voltage detection value input from voltage detection unit 1. Such storage unit 3 is, for example, a semiconductor memory functioning as a ring buffer. Additionally, storage unit 3 stores the selected instruction input from monitoring device B via instruction receiving unit 5. This selected instruction will be described later. Furthermore, storage unit 3 stores the electric field strength value input from electric field strength detection unit 6. This electric field strength value represents the electric field strength when the first voltage detection device A1 is directly communicating wirelessly with other voltage detection devices A2 to An or monitoring device B, and is obtained by electric field strength detection unit 6.

[0036] The equalization processing unit 4 operates the operation units of the m discharge units 2 based on the operation commands input from the command receiving unit 5. That is, when an equalization processing command for each battery cell of the first battery module M1 is input from the command receiving unit 5, the equalization processing unit 4 equalizes the voltage of each cell by turning on / off each electronic switch in the m discharge units 2.

[0037] For example, if the voltage of a specific battery cell among the m battery cells connected in series in the first battery module M1 is higher than the voltage of the other battery cells, the equalization processing unit 4 sets the electronic switch of the discharge unit 2, which is connected in parallel with the battery cell with the higher voltage, to the on state only, thereby forcing the battery cell with the higher voltage to discharge. As a result, the cell voltage of the specified battery cell decreases, and the cell voltage of the specified battery cell is equalized relative to the cell voltages of the other battery cells.

[0038] The command receiving unit 5 is a communication unit that wirelessly receives equalization processing commands, voltage transmission commands, or electric field strength transmission commands from the monitoring device B. As shown in the figure, the command receiving unit 5 has an antenna. Using this antenna, the command receiving unit 5 receives radio waves transmitted from the monitoring device B via a mesh network and extracts the equalization processing commands, voltage transmission commands, or electric field strength transmission commands contained in the radio waves (received waves). When extracting the equalization processing commands, voltage transmission commands, or electric field strength transmission commands from the received waves, the command receiving unit 5 outputs the equalization processing commands to the equalization processing unit 4, the voltage transmission commands to the voltage detection unit 1 and the data transmission unit 7, and the electric field strength transmission commands to the electric field strength detection unit 6 and the data transmission unit 7.

[0039] In this embodiment, the command receiving unit 5 wirelessly receives the selection command from the monitoring device B via a mesh network. The command receiving unit 5 receives radio waves transmitted from the monitoring device B via the mesh network, and if the selection command contained in the radio waves (received waves) is extracted, the selection command is output to the storage unit 3.

[0040] The electric field strength detection unit 6 measures the electric field strength between voltage detection devices A1-An and other voltage detection devices A1-An or monitoring devices B based on the electric field strength transmission command input from the command receiving unit 5, and outputs the measurement result as an electric field strength value. The electric field strength detection unit 6 measures the electric field strength, for example, based on the signal strength transmitted and received via an antenna. When an electric field strength transmission command is input, the electric field strength detection unit 6 performs wireless communication with other voltage detection devices A1-An or monitoring devices B capable of wireless communication. Thus, the electric field strength detection unit 6 measures the electric field strength between voltage detection devices A1-An and other voltage detection devices A1-An or monitoring devices B based on the electric field strength transmission command.

[0041] The data transmission unit 7 transmits voltage information (charging information) or electric field strength information (electric field strength value) of each battery cell obtained from the storage unit 3 to the communication unit of the monitoring device B. This data transmission unit 7 has an antenna, and when various transmission commands are input from the command receiving unit 5, it transmits the voltage information and / or electric field strength information to the monitoring device B via a mesh network according to the content of the transmission command.

[0042] The data transmission unit 7 generates transmission packets that store the battery voltage detection values ​​of each battery cell in the first battery module M1, the electric field strength values ​​between the first voltage detection device A1 and other voltage detection devices A2 to An (or monitoring devices B), and the identification number of the first voltage detection device A1. The data transmission unit 7 performs prescribed modulation processing on these transmission packets and transmits them. Furthermore, the data transmission unit 7 transmits the aforementioned transmission data packets to the other voltage detection devices A2 to An or monitoring devices B, as determined by the selection information stored in the storage unit 3.

[0043] Furthermore, if the first voltage detection device A1 forms at least a part of the information transmission path for transmitting information from other voltage detection devices A2 to An to the monitoring device B, the data transmission unit 7 will transmit data received from other voltage detection devices A2 to An (transmission sources) to voltage detection devices A2 to An or monitoring device B that are different from the transmission sources.

[0044] When the first voltage detection device A1 forms at least a part of the information transmission path for transmitting information from other voltage detection devices A2 to An to the monitoring device B, the data receiving unit 8 receives data sent to voltage detection devices A2 to An that are different from the transmission source from other voltage detection devices A2 to An (transmission source) or the monitoring device B (transmission source).

[0045] On the other hand, such as Figure 2 As shown, the monitoring device B includes a storage unit 11, a charge calculation unit 12, a path selection unit 13, a data receiving unit 14, a command sending unit 15, and a data sending unit 16.

[0046] The storage unit 11 is a semiconductor memory that functions as, for example, a ring buffer, storing the charge amount of the battery modules M1 to Mn input from the charge amount calculation unit 12. Additionally, the storage unit 11 stores battery voltage detection values ​​and electric field strength values ​​input from the data receiving unit 14.

[0047] The charging quantity calculation unit 12 calculates (acquires) the charging quantity of each battery module M1 to Mn based on the voltage information input from the voltage detection devices A1 to An, and stores the calculated charging quantity in the storage unit 11. In addition, the charging quantity calculation unit 12 creates equalization instructions as needed for equalization processing based on the unit voltage detection values ​​input from the voltage detection devices A1 to An, and outputs them to the instruction sending unit 15.

[0048] The path selection unit 13 selects voltage detection devices A1 to An for each voltage detection device A1 to An to form an information transmission path from the voltage detection devices A1 to An to the monitoring device B. The path selection unit 13 selects the voltage detection devices A1 to An for forming the information transmission path based on the charge amount of the battery modules M1 to Mn stored in the storage unit 11. For example, the path selection unit 13 selects voltage detection devices A2 to An to form an information transmission path from the first voltage detection device A1 to the monitoring device B based on the charge amount of the battery modules M1 to Mn.

[0049] In this embodiment, the path selection unit 13 selects the voltage detection devices A1 to An as follows: when a battery module M1 to Mn to which the voltage detection devices A1 to An forming the information transmission path are connected exists, and the charging amount is below a preset threshold, the voltage detection devices A1 to An connected to that battery module M1 to Mn are removed to form the information transmission path. Furthermore, before selecting the voltage detection devices A1 to An to form the information transmission path based on the charging amount of the battery modules M1 to Mn, the path selection unit 13 selects the voltage detection devices A1 to An to form the information transmission path based on the electric field strength value. The path selection unit 13 creates an electric field strength transmission command and acquires the electric field strength value of each of the voltage detection devices A1 to An. The information transmission path selection operation will be described in detail later.

[0050] The timing of the path selection operation performed by the path selection unit 13 for information transmission is not particularly limited. For example, it can be performed whenever a command is sent from the monitoring device B to the voltage detection devices A1 to An. Alternatively, the path selection operation of the path selection unit 13 can be performed for each predetermined period of time.

[0051] When the path selection unit 13 selects voltage detection devices A1 to An that form the information transmission path, it creates a selection command indicating the selected voltage detection devices A1 to An and outputs it to the command sending unit 15. Such selection information is input from the command sending unit 15 to each voltage detection device A1 to An via the grid network and stored in the storage unit 3 of each voltage detection device A1 to An.

[0052] The selection instruction includes information indicating that voltage detection devices A1-An will output information received from other voltage detection devices A1-An to any one of them or to monitoring device B. In other words, the selection instruction includes information indicating that voltage detection devices A1-An will output information received from other voltage detection devices A1-An or to monitoring device B. Such selection instructions are stored in the storage units 3 of each voltage detection device A1-An. In each voltage detection device A1-An, based on data received by the data receiving unit 8 from other voltage detection devices A1-An, the data transmitting unit 7 generates a transmission packet and sends the transmission packet to the recipient determined based on the selection instruction stored in the storage unit 3.

[0053] Furthermore, the path selection unit 13 creates voltage transmission commands and electric field strength transmission commands as needed, and outputs them to the command transmission unit 15. For example, when the path selection unit 13 is performing an information transmission path selection operation, it acquires the charging amount of battery modules M1 to Mn calculated by the charging amount calculation unit 12 and stored in the storage unit 11 as charging information, and acquires the electric field strength value stored in the storage unit 11 as electric field strength information. At this time, if the required charging amount and electric field strength value are not stored in the storage unit 11, the path selection unit 13 creates voltage transmission commands and electric field strength transmission commands, and sends the unit voltage detection value and electric field strength value to the voltage detection devices A1 to An via the command transmission unit 15.

[0054] The data receiving unit 14 is a communication unit that wirelessly receives voltage detection values ​​(battery voltage detection values) and electric field strength values ​​of each battery cell from the data transmitting unit 7. As shown in the figure, the data receiving unit 14 is equipped with a communication antenna, which is used to receive radio waves transmitted from each voltage detection device A1 to An. This data receiving unit 14 outputs the voltage detection values ​​and electric field strength values ​​of each battery cell received from the data transmitting unit 7 of each voltage detection device A1 to An to the storage unit 11.

[0055] The command transmitting unit 15 is a communication unit that wirelessly transmits equalization processing commands, voltage transmission commands, and selection commands to the command receiving unit 5. This command transmitting unit 15 transmits the equalization processing commands, voltage transmission commands, and selection commands as radio waves (transmission waves) using the aforementioned communication antenna. This command transmitting unit 15 has a predetermined modulation circuit that generates transmission waves by modulating the equalization processing commands based on a predetermined communication protocol.

[0056] The data transmission unit 16 is a communication unit that transmits the aforementioned equalization processing command, voltage transmission command, and various data other than the selected command, i.e., the data required by each voltage detection device A1 to An. This data transmission unit 16 transmits the aforementioned equalization processing command, voltage transmission command, and various data other than the selected command as radio waves (transmission waves) using the aforementioned communication antenna. Like the command transmission unit 15, the data transmission unit 16 has a predetermined modulation circuit, and generates transmission waves by modulating the data and identification number according to a pre-determined communication protocol.

[0057] Next, refer to Figure 3 The selection of the information transmission path in the battery monitoring system involved in this embodiment will be described in detail.

[0058] Figure 3 This is a flowchart illustrating the process of selecting an information transmission path. Furthermore, the process of selecting the information transmission path is the handling of creating the aforementioned selection instruction, and is performed by the path selection unit 13.

[0059] The path selection unit 13 first acquires electric field strength information and charging information (step S1). Here, the path selection unit 13 acquires the charging amount of battery modules M1 to Mn calculated by the charging amount calculation unit 12 and stored in the storage unit 11 as charging information, and acquires the electric field strength value stored in the storage unit 11 as electric field strength information.

[0060] Next, the path selection unit 13 performs a path search based on electric field strength information (step S2). Here, a search is performed for each voltage detection device A1 to An to select an information transmission path that maximizes the electric field strength value between voltage detection devices A1 to An (or between voltage detection devices A1 to An and monitoring device B).

[0061] Next, the path selection unit 13 determines whether the information transmission path obtained in step S2 is within a predetermined number of hops (step S3). Here, the number of hops represents the number of other voltage detection devices A1 to An traversed when communicating between a specified voltage detection device A1 to An and the monitoring device B. The predetermined number of hops is preset to meet the required communication speed, etc., and is stored in the storage unit 11 in advance, for example.

[0062] If the information transmission path obtained in step S2 is within a predetermined number of hops, the path selection unit 13 determines the information transmission path obtained in step S2 as the first path (step S4). On the other hand, if the information transmission path obtained in step S2 is not within a predetermined number of hops, the path selection unit 13 searches for other paths that are different from the information transmission path obtained in step S2 (step S5).

[0063] When the first path is determined in step S4, the path selection unit 13 determines whether there is a battery module M1 to Mn with a charge level below a threshold in the battery modules connected to the voltage detection devices A1 to An that form the first path (step S6). If there is a battery module M1 to Mn with a charge level below the threshold in step S6, the path selection unit 13 proceeds to step S5 to search for other paths that are different from the information transmission path obtained in step S2.

[0064] If, in step S6, the charge level of battery modules M1 to Mn is not below a threshold, the first path is selected as the information transmission path to be sent to voltage detection devices A1 to An (step S7), and then the communication frequency is set to "high" using the first path (step S8). Furthermore, "high" communication frequency means, for example, that the interval between sending and receiving communication information is shorter than in the case of "low" communication frequency, as described later.

[0065] If the path selection unit 13 moves to step S5 and searches for other paths, it determines whether the information transmission path obtained in step S5 is within a predetermined number of hops (step S9). Here, if the information transmission path obtained in step S5 is within the predetermined number of hops, the path selection unit 13 determines the information transmission path obtained in step S5 as the second path (step S10). On the other hand, if the information transmission path obtained in step S5 is not within the predetermined number of hops, the path selection unit 13 determines that communication cannot be performed (step S11) and ends the information transmission path selection operation.

[0066] When the second path is determined in step S10, the path selection unit 13 determines whether there is a case where the charge amount is below a threshold in the battery modules M1 to Mn connected to the voltage detection devices A1 to An that form the second path (step S12).

[0067] In step S12, if there are no battery modules M1 to Mn with a charge level below the threshold, the second path is selected as the information transmission path to be sent to the voltage detection devices A1 to An (step S13), and then the communication frequency is set to "high" using the second path (step S14).

[0068] In step S12, if any of the battery modules M1 to Mn have a charge level below a threshold, the path selection unit 13 selects a first path as the information transmission path to be sent to the voltage detection devices A1 to An (step S15), and then uses the first path to set the communication frequency to "low" (step S16). Furthermore, "low" communication frequency means, for example, minimizing the interval between sending and receiving communication information, thus extending the communication interval compared to a "high" communication frequency. In this way, by setting the communication frequency to "low," the power consumption of the battery modules M1 to Mn can be suppressed.

[0069] The path selection unit 13 performs the above-mentioned information transmission path selection operation for each voltage detection device A1 to An, and selects the voltage detection devices A1 to An that form the information transmission path for each voltage detection device A1 to An.

[0070] Figure 4A This is a schematic conceptual diagram used to illustrate the first path described above. Figure 4B This is a schematic conceptual diagram used to illustrate the second path described above. Additionally, in Figure 4A as well as Figure 4B In the diagram, the number of markings inside the battery indicator indicates the remaining battery capacity (i.e., charge level) of the battery module. Additionally, in... Figure 4A as well as Figure 4B In this context, the thickness of the wires connecting voltage detection devices to each other or to a monitoring device represents the intensity of the electric field. Additionally, in... Figure 4A and Figure 4B In the image, arrows indicate information transmission paths.

[0071] like Figure 4A As shown, in the first path, the voltage detection device is selected such that the path with the highest electric field strength becomes the information transmission path. On the other hand, as... Figure 4B As shown, when the battery module connected to the voltage detection device forming the first path has a small battery capacity, a second path is formed in a way that avoids connecting to the voltage detection device of these battery modules with less battery material.

[0072] Furthermore, as in steps S12, S15, and S16, when voltage detection devices A1 to An connected to battery modules M1 to Mn with low charge levels are used as information transmission paths, the communication frequency is reduced. That is, in this embodiment, when the charge level of battery modules M1 to Mn connected to voltage detection devices A1 to An forming the information transmission path is lower than a preset threshold, the communication frequency via this information transmission path is reduced compared to the case where the charge level of battery modules M1 to Mn connected to voltage detection devices A1 to An forming the information transmission path is greater than the preset threshold.

[0073] The battery monitoring system of this embodiment, as described above, includes: voltage detection devices A1 to An, each provided for a plurality of battery modules M1 to Mn, which acquire charging information of battery modules M1 to Mn and wirelessly communicate with each other to form an information transmission path for charging information; a monitoring device B, which monitors battery modules M1 to Mn based on the charging information input via the information transmission path; and a path selection unit 13, which selects voltage detection devices A1 to An that form an information transmission path to the monitoring device B for each voltage detection device A1 to An based on the charging information. Furthermore, in this embodiment, the path selection unit 13 is integrated into the monitoring device B as a function of the monitoring device B. In addition, in the battery monitoring method of this embodiment, by wirelessly communicating with each of the voltage detection devices A1 to An provided for each of the plurality of battery modules M1 to Mn, an information transmission path is formed from the voltage detection devices A1 to An to the monitoring device B that monitors the battery modules M1 to Mn, charging information of battery modules M1 to Mn is acquired, and voltage detection devices A1 to An that form an information transmission path are selected for each voltage detection device A1 to An based on the charging information.

[0074] In the battery monitoring method of this embodiment of the battery monitoring system, voltage detection devices A1 to An communicate wirelessly with each other to form a mesh network connecting each voltage detection device A1 to An and the monitoring device B. Furthermore, in this embodiment of the battery monitoring system, voltage detection devices A1 to An are selected to form information transmission paths from each voltage detection device A1 to An to the monitoring device B based on the charging states of battery modules M1 to Mn obtained by the voltage detection devices A1 to An. That is, the path selection unit 13 determines whether each of the voltage detection devices A1 to An can form an information transmission path based on the charging states of battery modules M1 to Mn obtained by the voltage detection devices A1 to An, and selects an information transmission path. In other words, according to this embodiment of the battery monitoring system, information transmission paths can be formed considering the charging states of battery modules M1 to Mn. For example, information transmission paths can be formed in a way that does not cause deviations in the charging amount of battery modules M1 to Mn.

[0075] In addition, in the battery monitoring system of this embodiment, when the charging amount of battery modules M1 to Mn connected to voltage detection devices A1 to An that form information transmission paths is lower than a preset threshold, the path selection unit 13 removes the voltage detection devices A1 to An connected to battery modules M1 to Mn whose charging amount is lower than the threshold and selects the voltage detection devices A1 to An that form information transmission paths.

[0076] According to this embodiment of the battery monitoring system, an information transmission path is formed by removing the voltage detection devices A1 to An connected to the battery modules M1 to Mn with low charge levels. Therefore, it is possible to prevent the power of the battery modules M1 to Mn with low charge levels from decreasing due to communication.

[0077] Furthermore, in the battery monitoring system of this embodiment, the path selection unit 13 selects voltage detection devices A1 to An that form the information transmission path, such that the number of voltage detection devices A1 to An forming the information transmission path is below a preset upper limit (below a predetermined number of hops). Therefore, the battery monitoring system according to this embodiment can suppress communication delays and the like caused by an increase in the number of hops.

[0078] Furthermore, in the battery monitoring system of this embodiment, when the charge level of battery modules M1 to Mn connected to voltage detection devices A1 to An forming the information transmission path is lower than a preset threshold, the monitoring device B makes the communication frequency of wireless communication via the information transmission path less than when the charge level of battery modules M1 to Mn connected to voltage detection devices A1 to An forming the information transmission path is greater than the preset threshold. Therefore, it is possible to suppress the power loss of battery modules M1 to Mn with low charge levels due to communication.

[0079] Furthermore, in the battery monitoring system of this embodiment, before selecting the voltage detection devices A1 to An that form the information transmission path to the monitoring device B, the path selection unit 13 selects the voltage detection devices A1 to An that form the information transmission path to the monitoring device B based on the electric field strength of the wireless communication of the voltage detection devices A1 to An, according to the charging information. Therefore, according to this embodiment, the information transmission path can be formed based on the path with high electric field strength.

[0080] (Second Implementation)

[0081] Next, a second embodiment of the present invention will be described. Furthermore, in this embodiment, descriptions of parts identical to those in the first embodiment described above are omitted or simplified.

[0082] Figure 5 This is a block diagram including the voltage detection device and monitoring device of the battery monitoring system in this embodiment. As shown in the figure, in this embodiment, the path selection unit 13 is set as a function of the first voltage detection device A1. In addition, the path selection unit 13 is also provided in other voltage detection devices A2 to An besides the first voltage detection device A1.

[0083] In this embodiment, for example, multiple path selection units 13 installed in multiple voltage detection devices A1 to An communicate with each other and cooperate to form an information transmission path. For instance, each path selection unit 13 acquires charging information (individual cell voltage detection value) and, based on this charging information, determines whether its installed voltage detection devices A1 to An can form an information transmission path. If a path selection unit 13 determines that its installed voltage detection devices A1 to An can form an information transmission path, it selects the voltage detection devices A1 to An that are physically closer to the monitoring device B and have a stronger electric field strength value as the destination for information transmission, based on the electric field strength value. By performing these actions separately in the path selection units 13 installed in each voltage detection device A1 to An, an information transmission path is formed for each voltage detection device A1 to An.

[0084] Furthermore, the path selection unit 13 can calculate the charging amount of battery modules M1 to Mn based on the battery voltage detection value stored in the storage unit 11, thereby obtaining the charging amount of battery modules M1 to Mn. Alternatively, the path selection unit 13 can also obtain the charging amount of battery modules M1 to Mn from the charging amount calculation unit 12 of the monitoring device B.

[0085] Even in this embodiment, the charging states of battery modules M1 to Mn can be taken into account to form an information transmission path. For example, the information transmission path can be formed in a way that the charging amounts of battery modules M1 to Mn do not deviate.

[0086] (Third Implementation)

[0087] Next, a third embodiment of the present invention will be described. Furthermore, in this embodiment, descriptions of parts identical to those in the first embodiment described above are omitted or simplified.

[0088] Figure 6 This is a block diagram including the voltage detection device and monitoring device of the battery monitoring system in this embodiment. As shown in the figure, in this embodiment, the path selection unit 13 is provided outside the monitoring device B and connected to the monitoring device B.

[0089] Such a path selection unit 13 is, for example, set as a function of the engine control unit (ECU), which selects voltage detection devices A1 to An that form an information transmission path while communicating with the monitoring device B.

[0090] Even in this embodiment, the charging states of battery modules M1 to Mn can be taken into account to form an information transmission path. For example, the information transmission path can be formed in a way that the charging amounts of battery modules M1 to Mn do not deviate.

[0091] The components of the host control unit, voltage detection unit 1, equalization processing unit 4, electric field strength detection unit 6, charge calculation unit 12, and path selection unit 13 are implemented, for example, by a computer processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components can be implemented using hardware (circuit unit; including circuitry) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and GPU (Graphics Processing Unit), or through a combination of software and hardware. The program can be pre-stored in a memory such as the storage unit 3, or stored in a removable storage medium such as a DVD or CD-ROM, and installed in the storage unit 3 by installing the storage medium onto a drive device. The CPU and memory can also be installed on a server connected to a network.

[0092] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. The shapes, combinations, etc. of the constituent components shown in the above embodiments are examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

Claims

1. A battery monitoring device, comprising: The charging status acquisition unit is set for multiple battery modules respectively, acquires the charging information of the battery modules, communicates wirelessly with each other, and can form an information transmission path for the charging information. The monitoring unit monitors the battery module based on the charging information input via the information transmission path; as well as The path selection unit, based on the charging information, selects the charging status acquisition unit that forms the information transmission path to the monitoring unit for each of the charging status acquisition units. The path selection section, If the charge level of the battery module connected to the charging status acquisition unit that forms the first information transmission path is lower than a preset threshold, The charging status acquisition unit connected to the battery module whose charging level is below the threshold is removed, and the charging status acquisition unit used to form the second information transmission path is selected instead. If the charge level of the battery module connected to the charging status acquisition unit that forms the second information transmission path is lower than a preset threshold, the charging status acquisition unit that forms the first information transmission path is reselected. The monitoring unit, Compared to the case where the battery module connected to the charging status acquisition unit that forms the information transmission path has a charge level higher than a preset threshold, If the charge level of the battery module connected to the charging status acquisition unit that forms the information transmission path is lower than a preset threshold, the communication frequency via the information transmission path is reduced.

2. The battery monitoring device according to claim 1, wherein, The path selection unit selects the charging status acquisition unit that forms the information transmission path in such a way that the number of the charging status acquisition units that form the information transmission path is below a preset upper limit.

3. The battery monitoring device according to claim 1 or 2, wherein, The path selection unit selects the charging status acquisition unit, which forms the information transmission path leading to the monitoring unit, based on the charging information. The charging status acquisition unit is selected based on the electric field strength of the wireless communication of the charging status acquisition unit, which forms the information transmission path to the monitoring unit.

4. A battery monitoring method, comprising forming an information transmission path from the charging state acquisition unit to a monitoring unit monitoring the battery modules through mutual wireless communication between charging state acquisition units separately provided for multiple battery modules. The battery monitoring method includes: Obtain the charging information of the battery module. Based on the charging information, for each charging status acquisition unit, the charging status acquisition unit that forms the information transmission path is selected. If the charge level of the battery module connected to the charging status acquisition unit that forms the first information transmission path is lower than a preset threshold, the charging status acquisition unit connected to the battery module with the charge level lower than the threshold is removed, and the charging status acquisition unit for forming the second information transmission path is selected. If the charge level of the battery module connected to the charging status acquisition unit that forms the second information transmission path is lower than a preset threshold, the charging status acquisition unit that forms the first information transmission path is reselected. Compared to the case where the battery module connected to the charging status acquisition unit forming the information transmission path has a charge level higher than a preset threshold, when the charge level of the battery module connected to the charging status acquisition unit forming the information transmission path is lower than a preset threshold, the communication frequency via the information transmission path is reduced.

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