Battery management system, battery management method, and program

Abstract

To provide a battery management system, a battery management method, and a program capable of estimating information for controlling charging and discharging even when sufficient measurement results are not obtained.SOLUTION: A battery management system 10 according to the present disclosure includes a first communication connection confirmation unit 11, a second communication connection confirmation unit 12, and an estimation unit 13. The first communication connection confirmation unit 11 confirms the communication state of a first communication connection connecting a microcontroller MC1 and a battery management unit BM that acquires a cell voltage and a pack temperature. The second communication connection confirmation unit confirms the communication state of a second communication connection connecting the microcontroller MC1 and a measurement unit M1 that measures a pack voltage and a pack current. The estimation unit 13 estimates charging / discharging information for controlling charging / discharging of the battery on the basis of information that the microcontroller MC1 can acquire according to the communication states of the first communication connection and the second communication connection.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a battery management system, a battery management method, and a program, and more particularly to a battery management system, a battery management method, and a program suitable for estimating information for controlling charge and discharge even when measurement results are not sufficiently obtained.

Background Art

[0002] In recent years, with the spread of electric vehicles, technologies related to batteries have been developed. In a battery, the voltage of each cell, the pack temperature of the battery pack, the pack current of the battery pack, and the pack voltage of the battery pack are measured, and the state of charge is estimated from the measurement results. Then, in the battery, for example, the charge and discharge of the battery are controlled to continue or stop based on the temperature and the state of charge.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In a battery, it is required to estimate information for controlling charge and discharge even when measurement results are not sufficiently obtained. Other problems and novel features will become apparent from the description of this specification and the accompanying drawings.

Means for Solving the Problems

[0004] The battery management system according to the present disclosure includes a first communication connection confirmation unit that confirms the communication state of a first communication connection connecting a microcontroller and a battery management unit that acquires the cell voltage of a plurality of cells and the pack temperature of the battery pack; a second communication connection confirmation unit that confirms the communication state of a second communication connection connecting the microcontroller and a measurement unit that measures the pack voltage and the pack current of the battery pack; An estimation unit is provided that estimates charge and discharge information for controlling charging and discharging of a battery based on information that can be acquired by the microcontroller according to the communication states of the first communication connection and the second communication connection.

[0005] The battery management method according to the present disclosure checks the communication state of a first communication connection connecting a microcontroller and a battery management unit that acquires the cell voltages of a plurality of cells and the pack temperature of a battery pack, checks the communication state of a second communication connection connecting the microcontroller and a measurement unit that measures the pack voltage and pack current of the battery pack, The computer executes a process of estimating charge and discharge information for controlling charging and discharging of a battery based on information that can be acquired by the microcontroller according to the communication states of the first communication connection and the second communication connection.

[0006] The program according to the present disclosure checks the communication state of a first communication connection connecting a microcontroller and a battery management unit that acquires the cell voltages of a plurality of cells and the pack temperature of a battery pack, checks the communication state of a second communication connection connecting the microcontroller and a measurement unit that measures the pack voltage and pack current of the battery pack, The computer is caused to execute a process of estimating charge and discharge information for controlling charging and discharging of a battery based on information that can be acquired by the microcontroller according to the communication states of the first communication connection and the second communication connection.

Advantages of the Invention

[0007] The present disclosure can provide a battery management system, a battery management method, and a program capable of estimating information for controlling charging and discharging even when measurement results cannot be sufficiently obtained.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings. Since the drawings are simplified, the technical scope of the embodiments should not be narrowly interpreted based on the description of these drawings. Also, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0010] In the following embodiments, when necessary for convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not independent of each other, and one is related to the other as a modification, application example, detailed description, supplementary description, etc. of part or all of the other. Also, in the following embodiments, when referring to the number of elements, etc. (including the number, numerical value, quantity, range, etc.), unless otherwise specified and unless it is clearly limited to a specific number in principle, it is not limited to that specific number, and it may be more than or less than the specific number.

[0011] Furthermore, in the following embodiments, the components (including operation steps, etc.) are not necessarily essential unless otherwise specified and unless they are clearly considered essential in principle. Similarly, in the following embodiments, when referring to the shape, positional relationship, etc. of components, etc., unless otherwise specified and unless it is clearly not the case in principle, it includes those that are substantially approximate or similar to the shape, etc. This also applies to the above numbers, etc. (including the number, numerical value, quantity, range, etc.).

[0012] <Embodiment 1> <Battery Management System> Hereinafter, with reference to the drawings, the configuration of the battery management system and the battery according to Embodiment 1 will be described. FIG. 1 is a block diagram illustrating the battery management system according to Embodiment 1. As shown in FIG. 1, the battery management system 10 includes a microcontroller MC1 and a battery management unit BM. In the example shown in FIG. 1, the microcontroller MC1 includes a first communication connection confirmation unit 11, a second communication connection confirmation unit 12, and an estimation unit 13. The measurement unit M1 is provided outside the battery management system 10.

[0013] As shown in FIG. 1, the microcontroller MC1 and the battery management unit BM are connected in a communicable configuration. The communication connection between the microcontroller MC1 and the battery management unit BM is referred to as the first communication connection.

[0014] Also, as shown in FIG. 1, the microcontroller MC1 and the measurement unit M1 are connected in a communicable configuration. The connection between the microcontroller MC1 and the measurement unit M1 is referred to as the second communication connection.

[0015] The first communication connection is not limited to a wired connection and may be a wireless connection. The first communication connection confirmation unit 11 confirms the communication state of the first communication connection. More specifically, the first communication connection confirmation unit 11 determines whether the communication state of the first communication connection is a disconnected state.

[0016] Also, the second communication connection is a wired connection. The second communication connection confirmation unit 12 confirms the communication state of the second communication connection. More specifically, the second communication connection confirmation unit 12 determines whether the communication state of the second communication connection is a disconnected state.

[0017] The battery management unit BM acquires the cell voltages of a plurality of cells and the pack temperature of the battery pack. The measurement unit M1 measures the pack voltage and pack current of the battery pack.

[0018] The microcontroller MC1 and the battery management unit BM communicate via the first communication connection. Thus, the microcontroller MC1 acquires the cell voltages and the pack temperature of the battery pack acquired by the battery management unit BM.

[0019] Also, the microcontroller MC1 and the measurement unit M1 communicate via the second communication connection. Thus, the microcontroller MC1 acquires the pack voltage and pack current of the battery pack measured by the measurement unit M1.

[0020] That is, when the first communication connection and the second communication connection are in a communication state, the microcontroller MC1 acquires the cell voltages, pack temperature, pack voltage, and pack current of a plurality of cells. For example, when the first communication connection is in a disconnected state and the second communication connection is in a communication state, the microcontroller MC1 cannot acquire the cell voltages and pack temperature of the plurality of cells, but can acquire the pack voltage and pack current. Thus, depending on the communication states of the first communication connection and the second communication connection, the information that the microcontroller MC1 can acquire is different.

[0021] The estimation unit 13 estimates charge / discharge information for controlling the charge and discharge of the battery based on the information that the microcontroller MC1 can acquire according to the communication states of the first communication connection and the second communication connection.

[0022] That is, the estimation unit 13 estimates charge / discharge information for controlling the charge and discharge of the battery based on the information from the first communication connection or the second communication connection whose communication state is not disconnected. When the communication states of the first communication connection and the second communication connection are disconnected, the estimation unit 13 estimates charge / discharge information for controlling the charge and discharge of the battery based on the information that the microcontroller could acquire before the communication states of the first communication connection and the second communication connection were disconnected.

[0023] Thus, the battery management system 10 according to Embodiment 1 estimates charge / discharge information for controlling the charge and discharge of the battery based on the information that the microcontroller MC1 can acquire according to the communication states of the first communication connection and the second communication connection. Thereby, the battery management system 10 can estimate the information for controlling the charge and discharge even if sufficient measurement results cannot be obtained.

[0024] <Battery Management Method> Subsequently, the battery management method according to Embodiment 1 will be described. FIG. 2 is a flowchart showing the battery management method according to Embodiment 1. The main bodies of each step are the first communication connection confirmation unit 11, the second communication connection confirmation unit 12, and the estimation unit 13 shown in FIG. 1.

[0025] First, the first communication connection confirmation unit 11 checks the communication state of the first communication connection that connects the microcontroller and the battery management unit that acquires the cell voltages of a plurality of cells and the pack temperature of the battery pack (step ST1).

[0026] Next, the second communication connection confirmation unit 12 checks the communication state of the second communication connection that connects the microcontroller and the measurement unit that measures the pack voltage and pack current of the battery pack (step ST2).

[0027] Next, the estimation unit 13 estimates charge / discharge information for controlling the charging and discharging of the battery based on the information that can be acquired by the microcontroller according to the communication states of the first communication connection and the second communication connection (step ST3).

[0028] Thus, the battery management method according to Embodiment 1 estimates charge / discharge information for controlling the charging and discharging of the battery based on the information that can be acquired by the microcontroller according to the communication states of the first communication connection and the second communication connection. Thereby, the battery management method according to Embodiment 1 can estimate information for controlling the charging and discharging even if sufficient measurement results cannot be obtained.

[0029] <Embodiment 2> <Battery Configuration> Hereinafter, with reference to the drawings, the configuration of the battery management system and the battery according to Embodiment 2 will be described. FIGS. 3 and 4 are block diagrams illustrating the battery management system according to Embodiment 2. The block diagrams shown in FIGS. 3 and 4 show the block diagram shown in FIG. 1 in detail.

[0030] As shown in FIGS. 3 and 4, the battery management system 20 includes a microcontroller MC2 and battery management units BM1 to BMn. FIGS. 3 and 4 only differ in the types of communication connections between the microcontroller MC2 and the battery management units BM1 to BMn, and the other configurations are the same.

[0031] FIG. 3 is a diagram showing a state in which the microcontroller MC2 and the battery management units BM1 to BMn are wirelessly connected. FIG. 4 is a diagram showing a state in which the microcontroller MC2 and the battery management units BM1 to BMn are wired-connected. The discharge device 50 or the charging device 60 is connected to the battery pack BP1 and performs discharging or charging.

[0032] As shown in FIGS. 3 and 4, the control device CU1 is provided connected between the battery pack BP1 and the discharge device 50 or the charging device 60. The control device CU1 mediates between the battery pack BP1 and the discharge device 50 or the charging device 60. More specifically, before charging or discharging, the control device CU1 inquires of each device whether the discharge device 50, the charging device 60, and the battery management system 20 are operating properly. Then, after confirming that the discharge device 50, the charging device 60, and the battery management system 20 are operating properly, the control device CU1 requests each device to charge or discharge. Note that if the discharge device 50 and the charging device 60 have a mediation function, the control device CU1 may not be provided. In the embodiments described later, since the configurations of the discharge device 50 or the charging device 60 and the control device CU1 are the same, the description thereof is omitted.

[0033] As shown in FIGS. 3 and 4, the microcontroller MC2 includes a first communication connection confirmation unit 11, a second communication connection confirmation unit 12, an estimation unit 13, a control unit 14, and a storage unit 15.

[0034] The battery management units BM1 to BMn will be described. As shown in FIG. 3, in the battery B1, the battery pack BP1 includes a plurality of battery management units BM1 to BMn. Also, in the battery B1, the battery pack BP1 includes a plurality of battery cells S1 to Sn.

[0035] A plurality of battery cells S1 to Sn are allocated and connected to each of the battery management units BM1 to BMn. From this, the battery management units BM1 to BMn acquire the cell voltages of the plurality of battery cells S1 to Sn. Hereinafter, the battery cells S1 to Sn are denoted as cells S1 to Sn.

[0036] In addition, temperature sensors T1 to Tn are allocated and connected to each of the battery management units BM1 to BMn. The temperature sensors T1 to Tn measure the pack temperature of the battery pack BP1. From this, the battery management units BM1 to BMn acquire the pack temperature of the battery pack BP1.

[0037] In this way, the battery management units BM1 to BMn acquire the cell voltages of the plurality of cells S1 to Sn and the pack temperature of the battery pack BP1.

[0038] The first communication connection will be described. The first communication connection is a communication connection that connects the microcontroller MC2 and the battery management units BM1 to BMn. The first communication connection is not limited to the wireless connection shown in FIG. 3, and as shown in FIG. 4, it may be a wired connection.

[0039] That is, as shown in FIG. 3, the microcontroller MC2 and the battery management units BM1 to BMn are not limited to being wirelessly connected via the wireless ICs (Integrated Circuits) 1 to wireless ICn and the wireless IC101. As shown in FIG. 4, the microcontroller MC2 and the battery management units BM1 to BMn may be wired-connected via the communication IC100.

[0040] The first communication connection confirmation unit 11 shown in FIGS. 3 and 4 confirms the communication state of the first communication connection. More specifically, the first communication connection confirmation unit 11 determines whether or not the communication state of the first communication connection is a disconnected state.

[0041] The measurement unit will be described. The measurement unit is composed of a voltage sensor SV and a current sensor SI. As shown in FIG. 3, the battery pack BP1 includes a voltage sensor SV and a current sensor SI. The voltage sensor SV measures the pack voltage of the battery pack BP1. The current sensor SI measures the pack current of the battery pack BP1.

[0042] The second communication connection will be described. The second communication connection is a communication connection that connects the microcontroller MC2, the voltage sensor SV, and the current sensor SI. As shown in FIGS. 3 and 4, the second communication connection is a wired connection.

[0043] The second communication connection confirmation unit 12 shown in FIGS. 3 and 4 checks the communication state of the second communication connection. More specifically, the second communication connection confirmation unit 12 determines whether the communication state of the second communication connection is a disconnected state.

[0044] The microcontroller MC1 and the battery management unit BM1 communicate via the first communication connection. From this, the microcontroller MC1 acquires the cell voltages of the cells S1 to Sn and the pack temperature of the battery pack BP1.

[0045] Also, the microcontroller MC1 and the measurement unit M1 communicate via the second communication connection. From this, the microcontroller MC1 acquires the pack voltage and the pack current of the battery pack BP1.

[0046] That is, when the first communication connection and the second communication connection are in a communication state, the microcontroller MC1 acquires the cell voltages of the plurality of cells S1 to Sn, the pack temperature of the battery pack BP1, the pack voltage of the battery pack BP1, and the pack current of the battery pack BP1.

[0047] <When the first communication connection and the second communication connection are in a communication state> Next, when the first communication connection and the second communication connection are in a communication state, the information stored in the storage unit 15 will be described. FIG. 5 is a diagram showing the relationship between the charging state of the cell and the cell voltage, and the relationship between the charging state of the battery and the pack voltage.

[0048] The microcontroller MC2 acquires the cell voltage and the pack temperature. From this, as shown in the upper part of FIG. 5, the storage unit 15 stores the relationship between the charging state of the cell and the cell voltage at each temperature. In the upper part of FIG. 5, three curves with different temperatures are shown. In the upper part of FIG. 5, it shows that when the temperature decreases, even if the charging state of the same cell is the same, the required cell voltage decreases.

[0049] The microcontroller MC2 acquires the pack voltage and the pack temperature. From this, as shown in the lower part of FIG. 5, the storage unit 15 stores the relationship between the charging state of the battery and the pack voltage at each temperature. In the lower part of FIG. 5, three curves with different temperatures are shown. In the lower part of FIG. 5, it shows that when the temperature decreases, even if the charging state of the same cell is the same, the required pack voltage decreases.

[0050] The microcontroller MC2 acquires the pack temperature and the pack current. From this, the storage unit 15 stores the relationship between the pack current and the change in pack temperature during charge and discharge. FIG. 6 is a diagram showing the change in pack current with respect to time, the change in pack temperature with respect to time, and the relationship between the pack current and the change in pack temperature.

[0051] As shown in the upper and middle parts of FIG. 6, the storage unit 15 stores the change in pack current with respect to time and the change in pack temperature with respect to time. The microcontroller MC2 uses the change in pack current with respect to time shown in the upper part of FIG. 6 and the change in pack temperature with respect to time shown in the middle part of FIG. 6 to calculate the relationship between the pack current and the change in pack temperature shown in the lower part of FIG. 6. Then, the storage unit 15 stores the relationship between the pack current and the change in pack temperature shown in the lower part of FIG. 6.

[0052] <Estimation of the charging state of the cell and the charging state of the battery pack> Next, when the first communication connection and the second communication connection are in a communication state, a method for estimating the charging state of the cells and the charging state of the battery in the estimation unit 13 will be described.

[0053] The microcontroller MC2 acquires the cell voltages and the pack temperature of a plurality of cells. The estimation unit 13 estimates the charging state of the cells using the upper part of FIG. 5 based on the cell voltages and the pack temperature acquired by the microcontroller MC2.

[0054] More specifically, the description will be given. The estimation unit 13 identifies the curve having the pack temperature acquired by the microcontroller MC2 among the curves in the upper part of FIG. 5. Then, the estimation unit 13 identifies the charging state of the cell having the cell voltage acquired by the microcontroller MC2 from that curve. In this way, the estimation unit 13 estimates the charging state of the cells.

[0055] The microcontroller MC2 acquires the pack temperature and the pack voltage of a plurality of cells. The estimation unit 13 estimates the charging state of the battery pack BP1 using the lower part of FIG. 5 based on the pack voltage and the pack temperature acquired by the microcontroller MC2.

[0056] More specifically, the description will be given. The estimation unit 13 identifies the curve having the pack temperature acquired by the microcontroller MC2 among the curves in the lower part of FIG. 5. Then, the estimation unit 13 identifies the charging state of the battery B1 having the pack voltage acquired by the microcontroller MC2 from that curve. In this way, the estimation unit 13 estimates the charging state of the battery B1.

[0057] In this way, in the battery management system 20, the storage unit 15 stores the information shown in FIGS. 5 and 6. Therefore, when the first communication connection and the second communication connection are in a communication state, the battery management system 20 can estimate the charging state of the cells and the charging state of the battery B1 based on the information in the storage unit 15. Note that the storage unit 15 may store the charging state and the pack temperature of the battery B1 in association with the time.

[0058] <When the first communication connection and the second communication connection are in a disconnected state> Next, the case where the first communication connection and the second communication connection are in a disconnected state will be described. The storage unit 15 stores the relationship between the charge state of the cell and the cell voltage at each temperature and the relationship between the charge state of the battery and the pack voltage at each temperature shown in FIG. 5. Here, the configuration of the battery and the order of the method by which the estimation unit 13 estimates the pack temperature and the charge state of the battery will be described.

[0059] First, the configuration of the battery when the first communication connection and the second communication connection are in a disconnected state will be described. When the first communication connection is in a disconnected state, it includes the case where the wireless IC 101 connected to the microcontroller or all of the wireless ICs 1 to ICn connected to the battery management units BM1 to BMn are abnormal. Also, when the second communication connection is in a disconnected state, it includes the case where the voltage sensor SV and the current sensor SI are malfunctioning. Note that when the first communication connection and the second communication connection are in a disconnected state, it includes the occurrence of communication data corruption.

[0060] FIG. 7 is a block diagram illustrating the battery management system according to Embodiment 2. As shown in FIG. 7, since the first communication connection is in a disconnected state, the connection (first communication connection) of the wireless ICs 1 to ICn and the wireless IC 101 is indicated by a dotted line. Also, as shown in FIG. 7, since the second communication connection is in a disconnected state, the connection (second communication connection) between the microcontroller MC2 and the voltage sensor SV and the current sensor SI is indicated by a dotted line.

[0061] In the configuration of the battery B1 shown in FIG. 7, the configuration other than the connection states of the first communication connection and the second communication connection is the same as that in FIG. 3. Hereinafter, the estimation unit 13 will be described as estimating the pack temperature and the charge state of the battery B1 as charge and discharge information for controlling the charge and discharge of the battery.

[0062] When the first communication connection is in a disconnected state and the second communication connection is in a disconnected state, the estimation unit 13 estimates the pack temperature and the charge state of the battery B1 as follows. The estimation unit 13 Based on the pack temperature acquired by the microcontroller MC2 before the first communication connection is disconnected, and the pack voltage acquired by the microcontroller MC2 before the second communication connection is disconnected, estimate the pack temperature and the state of charge of the battery B1.

[0063] Referring to the lower part of FIG. 5, a more specific description will be given. The storage unit 15 stores the relationship between the state of charge of the battery and the pack voltage at each temperature shown in the lower part of FIG. 5. The estimation unit 13 identifies the curve having the pack temperature acquired by the microcontroller MC2 among the curves in the lower part of FIG. 5. Then, the estimation unit 13 identifies the state of charge of the battery B1 having the pack voltage acquired by the microcontroller MC2 from that curve.

[0064] In this way, by using the pack temperature acquired by the microcontroller MC2 before the first communication connection is disconnected and the pack voltage acquired by the microcontroller MC2 before the second communication connection is disconnected, the estimation unit 13 can estimate the state of charge of the battery B1. Further, the estimation unit 13 estimates the pack temperature acquired by the microcontroller MC2 as the temperature of the battery pack BP1 before the first communication connection is disconnected.

[0065] In this way, even when the first communication connection and the second communication connection are in a disconnected state and measurement results (cell voltage, pack temperature, pack voltage, pack current) cannot be sufficiently obtained, the battery management system 20 can estimate the pack temperature and the state of charge of the battery B1.

[0066] Here, the estimation unit 13 estimated the pack temperature and the state of charge of the battery from the pack temperature acquired by the microcontroller MC1 before the first communication connection was disconnected and the pack voltage acquired by the microcontroller MC2 before the second communication connection was disconnected. Since the microcontroller MC2 periodically stores the pack temperature and the state of charge in the storage unit 15, the estimation unit 13 may estimate the temperature stored by the microcontroller MC1 as the pack temperature before the first communication connection is disconnected. Further, the estimation unit 13 may estimate the state of charge stored by the microcontroller MC1 as the state of charge of the battery before the first communication connection and the second communication connection are disconnected.

[0067] <Control Example> Here, the control unit 14 will be described with reference to FIGS. 3 and 8. FIG. 8 is a diagram showing the relationship between the state of charge of the battery and the pack voltage at each temperature. The control unit 14 controls to continue discharging or charging based on the temperature estimated by the estimation unit 13 and the state of charge of the battery B1. Further, when the temperature estimated by the estimation unit 13 and the state of charge of the battery B1 exceed a predetermined value, the control unit 14 controls the relay R1 in FIG. 3 to cut off the charge and discharge of the battery B1.

[0068] In FIG. 8, a point P1 determined from the pack temperature estimated by the estimation unit 13 and the state of charge of the battery B1 is shown. In FIG. 8, the state of charge in the charge stop state or the discharge stop state is indicated by a dotted line. When the battery B1 is charging, the point P1 moves to the right along the curve so as to reach the charge stop state. When the battery B1 is discharging, the point P1 moves to the left along the curve so as to reach the discharge stop state.

[0069] The control unit 14 calculates the remaining time indicating the time until the state of charge in the discharge stop state or the charge stop state is reached from the state of charge of the battery (point P1) estimated by the estimation unit 13. A specific description will be given taking the case of charging as an example with reference to FIG. 8.

[0070] As shown in FIG. 8, when the charge stop state is 70% and the charge state of point P1 is 50%, the control unit 14 determines that there is a remaining charge of 20% until the charge stop state is reached. The control unit 14 calculates the remaining time indicating the time until the charge state of the charge stop state is reached by dividing the remaining charge by a predetermined pack current. The predetermined pack current is, for example, the maximum charge current. The same applies to the case of discharging. Then, the control unit 14 controls to continue discharging or charging during the remaining time.

[0071] As described above, the battery management system 20 according to Embodiment 2 calculates the remaining time indicating the time until the charge state of the discharge stop state or the charge stop state is reached from the charge state of the battery estimated by the estimation unit 13. Then, the battery management system 20 controls to continue discharging or charging during the remaining time. Such a method for controlling the discharge or charge of the battery is the same in Embodiments 3 and 4 described later.

[0072] With such a configuration, the battery management system 20 can continue to perform charging and discharging of the battery for a certain period when the first communication connection and the second communication connection are in a disconnected state. For example, when the battery management system 20 is used in an electric vehicle and the battery B1 is mounted, it can be utilized as follows.

[0073] Even when the first communication connection and the second communication connection are in a disconnected state, the control unit 14 controls the relay R1 and controls to continue discharging or charging from the temperature estimated by the estimation unit 13 and the charge state of the battery without interrupting the charging and discharging of the battery B1. Thereby, it is possible to secure a certain time until the electric vehicle in motion travels to the side of the road. That is, when the battery management system 20 is used in an electric vehicle and the battery is mounted, the degenerate operation of the electric vehicle can be realized.

[0074] Here, the control unit 14 calculated the remaining time by dividing the remaining charge amount by a predetermined pack current. Then, the control unit 14 was described as controlling to continue discharging or charging during the calculated remaining time. However, it is not limited to this, and the control unit 14 may continue discharging or charging during a shortened time of the calculated remaining time. By adopting such a configuration, the control unit 14 can control to continue discharging or charging more safely.

[0075] Note that in FIG. 8, the maximum temperature of the pack temperature of the battery pack BP1 is shown. Generally, the pack temperature rises with charge and discharge. When the pack temperature estimated by the estimation unit 13 becomes equal to or higher than the maximum temperature, the control unit 14 controls the relay R1 in FIG. 3 to cut off the charge and discharge of the battery. Thereby, safety can be ensured.

[0076] Here, for the purpose of increasing the capacity and efficiency of the battery, the number of cells in the battery pack tends to increase. As the number of cells increases, when the number of battery management units increases, the communication lines between the battery management units and the communication IC (FIG. 3) increase.

[0077] However, compared with FIG. 4, in FIG. 3, since the first communication connection is a wireless connection, such a problem can be solved. Also, as shown in FIG. 3, when the first communication connection is a wireless connection, an increase in man-hours during the assembly of the battery pack and the repair of the battery management system can be suppressed. Furthermore, as shown in FIG. 3, when the first communication connection is a wireless connection, redesign of the communication line path is not required when laying out the battery. In addition, as shown in FIG. 3, when the first communication connection is a wireless connection, the space of the communication line can be allocated to the space of the cell, so that the capacity of the cell can be increased.

[0078] <Embodiment 3> <When the first communication connection is in a disconnected state and the second communication connection is in a communication state> Next, the configuration of the battery management system and the battery according to Embodiment 3 will be described. FIG. 9 is a block diagram illustrating the battery management system according to Embodiment 3. The battery management system 30 includes a microcontroller MC3 and battery management units BM1 to BMn. The microcontroller MC3 includes a first communication connection confirmation unit 11, a second communication connection confirmation unit 12, an estimation unit 13, a control unit 14, a first storage unit 16, and a second storage unit 17.

[0079] The first communication connection confirmation unit 11, the second communication connection confirmation unit 12, and the control unit 14 shown in FIG. 9 are the same as those in Embodiment 2, so the description thereof will be omitted. Hereinafter, the battery configuration, the first storage unit 16, the second storage unit 17, and the estimation unit 13 will be described in detail in this order.

[0080] First, the battery configuration will be described. In FIG. 9, since the first communication connection is in a disconnected state and the second communication connection is in a communication state, the connection of the wireless ICs 1 to ICn and the wireless IC 101 (the first communication connection) is indicated by a dotted line.

[0081] Next, the first storage unit 16 and the second storage unit 17 will be described. The first storage unit 16 stores the relationship between the charge state of the cell and the cell voltage at each temperature and the relationship between the charge state of the battery and the pack voltage at each temperature shown in FIG. 5. That is, the first storage unit 16 stores the correspondence information of the cell voltage, the charge state of the cell, and the pack temperature (the upper part of FIG. 5) and the correspondence information of the pack voltage, the charge state of the battery, and the pack temperature (the lower part of FIG. 5).

[0082] The second storage unit 17 stores the change in the pack current with respect to time, the change in the pack temperature with respect to time, and the relationship between the pack current and the change in the pack temperature shown in FIG. 6. Note that the first storage unit 16 and the second storage unit 17 periodically store the pack temperature, the charge state of the cell, and the charge state of the battery acquired by the microcontroller MC3.

[0083] As shown in FIG. 9, since the second communication connection is in a communication state, the microcontroller MC3 can acquire the pack current. Therefore, when the microcontroller MC3 detects that the pack current is flowing, it can detect that the battery B1 is in a charge / discharge state. On the other hand, when the microcontroller MC3 detects that the pack current is not flowing, it can detect that the battery is in a resting state.

[0084] Hereinafter, the estimation unit 13 will be described separately for the case where the battery is in a resting state and the case where the battery is in a charge / discharge state. Further, hereinafter, the estimation unit 13 will be described as estimating the pack temperature and the state of charge of the battery as charge / discharge information for controlling the charge / discharge of the battery.

[0085] <When the battery is in a resting state> A method for the estimation unit 13 to estimate the temperature and the state of charge when the battery is in a resting state will be described. First, a method for the estimation unit 13 to estimate the temperature based on the information stored in the first storage unit 16 (the lower part of FIG. 5) will be described.

[0086] As shown in FIG. 9, since the second communication connection is in a communication state, the microcontroller MC3 can acquire the pack voltage. Further, the first storage unit 16 stores the state of charge of the battery acquired by the microcontroller MC3 before the first communication connection is disconnected.

[0087] From this, the estimation unit 13 estimates the pack temperature using the relationship between the state of charge and the pack voltage at each temperature stored in the first storage unit 16 (the lower part of FIG. 5). This will be described more specifically with reference to FIG. 10. FIG. 10 is a diagram showing the relationship between the state of charge of the battery and the pack voltage at each temperature. FIG. 10 is the same as the lower part of FIG. 5 and is an explanatory diagram for explaining the estimation unit 13 in more detail.

[0088] As shown in FIG. 10, the estimation unit 13 can estimate, as the pack temperature, the temperature corresponding to the state of charge of the battery before the pack voltage and the first communication connection are disconnected (immediately before suspension) among the temperatures of the first storage unit 16. In other words, as shown in FIG. 10, the estimation unit 13 estimates, as the pack temperature, the temperature of curve C1 that satisfies both conditions of the state of charge of the battery before the pack voltage and the first communication connection are disconnected (immediately before suspension).

[0089] Next, a method for the estimation unit 13 to estimate the state of charge of the battery based on the information stored in the first storage unit 16 will be described. As described above, the estimation unit 13 estimates the pack temperature. Also, since the second communication connection is in a communication state, the microcontroller MC3 can acquire the pack voltage.

[0090] From this, the estimation unit 13 can estimate the state of charge of the battery using the relationship between the state of charge and the pack voltage at each temperature stored in the first storage unit 16 (the lower part of FIG. 5). A more specific explanation will be given with reference to FIG. 11. FIG. 11 is a diagram showing the relationship between the state of charge of the battery and the pack voltage at each temperature. FIG. 11 is the same as the lower part of FIG. 5 and is an explanatory diagram for explaining the estimation unit 13 in more detail.

[0091] As shown in FIG. 11, the estimation unit 13 can estimate, as the state of charge of the battery, the state of charge corresponding to the estimated pack temperature and the pack voltage acquired by the microcontroller MC3. In other words, as shown in FIG. 11, the estimation unit 13 estimates, as the state of charge of the battery, the state of charge G1 having the pack voltage acquired by the microcontroller MC3 from curve C1 of the estimated pack temperature.

[0092] In this way, when the battery is in a suspended state, the battery management system 30 can estimate the pack temperature and the state of charge of the battery in order to control charge and discharge even if measurement results (cell voltage, pack temperature) cannot be sufficiently obtained.

[0093] Note that the pack temperature changes depending on the ambient temperature as time elapses since the timing when the battery enters the rest state. Therefore, the estimation unit 13 estimates the pack temperature and the state of charge of the battery using FIG. 10. With such a configuration, even if the temperature and the state of charge change from the timing when the battery enters the rest state, the battery management system 30 can accurately estimate the pack temperature and the state of charge of the battery.

[0094] <When the battery is in the charge / discharge state> A method for the estimation unit 13 to estimate the temperature and the state of charge when the battery is in the charge / discharge state will be described. First, a method for the estimation unit 13 to estimate the temperature based on the information stored in the second storage unit 17 (the lower part of FIG. 6) will be described. Since the second communication connection is in the communication state, the microcontroller MC3 can acquire the pack current. Also, the second storage unit 17 stores the pack temperature acquired by the microcontroller MC3 before the first communication connection is disconnected.

[0095] From this, the estimation unit 13 can estimate the change in the pack temperature from the pack current using the relationship between the pack current stored in the second storage unit 17 and the change in the pack temperature (the lower part of FIG. 6). Then, the estimation unit 13 estimates, as the pack temperature, the temperature obtained by correcting the estimated temperature change with respect to the pack temperature before the first communication connection is disconnected.

[0096] For example, when the pack temperature before the first communication connection is disconnected is 20 degrees and the change in the pack temperature (rise) estimated by the estimation unit 13 is 3 degrees, the estimation unit 13 estimates that 23 degrees is the pack temperature.

[0097] Next, a method for the estimation unit 13 to estimate the state of charge will be described. Since the second communication connection is in the communication state, the microcontroller MC3 can acquire the pack current. Also, the second storage unit 17 stores the state of charge acquired by the microcontroller MC3 before the first communication connection is disconnected.

[0098] Here, the microcontroller MC1 is measuring time. Therefore, the estimation unit 13 can calculate the integrated value of the current by multiplying the pack current by time. From this, the estimation unit 13 estimates, as the state of charge of the battery, the state of charge obtained by correcting the integrated value of the pack current with respect to the state of charge of the battery before the first communication connection is disconnected.

[0099] In this way, when the battery is in a charge / discharge state, the battery management system 30 can estimate the pack temperature and the state of charge of the battery in order to control the charge / discharge even if the measurement results (cell voltage, pack temperature) are not sufficiently obtained.

[0100] As described above, when the first communication connection is in a disconnected state and the second communication connection is in a communication state, the estimation unit 13 estimates the temperature of the battery pack and the state of charge of the battery based on the pack voltage or the pack current. Thereby, the battery management system 30 can estimate the pack temperature and the state of charge of the battery in order to control the charge / discharge even if the measurement results are not sufficiently obtained.

[0101] <When the first communication connection is in a communication state and the second communication connection is in a disconnected state> When the first communication connection is in a communication state and the second communication connection is in a disconnected state, the microcontroller MC1 cannot acquire the pack voltage and the pack current. On the other hand, since the first communication connection is in a communication state, the microcontroller MC1 can acquire the cell voltage and the pack temperature.

[0102] From this, the estimation unit 13 can estimate the state of charge of the cell based on the information in the upper part of FIG. 5 in the first storage unit 16. More specifically, the estimation unit 13 identifies the curve having the pack temperature acquired by the microcontroller MC3 among the curves in the upper part of FIG. 5. Then, the estimation unit 13 estimates, as the state of charge of the cell, the state of charge having the cell voltage acquired by the microcontroller MC3 from that curve.

[0103] Then, the estimation unit 13 estimates the state of charge of the battery from the state of charge of the cells. More specifically, when the battery is in a charged state, the estimation unit 13 estimates the highest state of charge among the states of charge of the cells as the state of charge of the battery. Further, when the battery is in a discharged state, the estimation unit 13 estimates the lowest state of charge among the states of charge of the cells as the state of charge of the battery.

[0104] Note that the estimation unit 13 estimates the state of charge of the cells at predetermined time intervals. From this, the estimation unit 13 can estimate the pack current by dividing the state of charge obtained by subtracting the state of charge of the cells before the elapse of a predetermined time from the state of charge of the cells after the elapse of a predetermined time by the predetermined time.

[0105] <Embodiment 4> <When any connection between the microcontroller and the battery management unit is in a disconnected state> Subsequently, the configuration of the battery management system and the battery according to Embodiment 4 will be described. FIG. 12 is a block diagram illustrating the battery management system according to Embodiment 4. The battery management system 40 includes a microcontroller MC4 and battery management units BM1 to BMn. The microcontroller MC4 includes a first communication connection confirmation unit 11, a second communication connection confirmation unit 12, and an estimation unit 13.

[0106] Regarding the first communication connection confirmation unit 11 and the second communication connection confirmation unit 12 shown in FIG. 12, since they are the same as those in Embodiments 1 to 3, the description thereof will be omitted. Hereinafter, the configuration of the battery and the estimation unit 13 will be described in detail in this order. Although not shown in FIG. 12, the microcontroller MC4 may include a control unit as in Embodiments 2 and 3.

[0107] First, the configuration of the battery will be described. Among the connections between the microcontroller MC4 and the battery management units BM1 to BMn, when a part is in a disconnected state, it includes the case where the wireless IC101 connected to the microcontroller is normal and some of the wireless ICs 1 to ICn connected to the battery management units BM1 to BMn are abnormal.

[0108] In FIG. 12, since the wireless IC1 of the battery management unit BM1 is abnormal and the connection (part of the first communication connection) between the microcontroller MC4 and the battery management unit BM1 is in a disconnected state, the wireless IC1 is shown by a dotted line. Hereinafter, the estimation unit 13 will be described as estimating the pack temperature and the state of charge of the battery as charge and discharge information for controlling the charge and discharge of the battery.

[0109] Since the connections (parts of the first communication connection) of the wireless IC1 and the wireless IC101 are disconnected, the microcontroller MC4 cannot acquire the cell voltage and the pack temperature under the battery management unit BM1.

[0110] In this case, the estimation unit 13 estimates the cell voltage and the pack temperature acquired by the microcontroller MC1 from the battery management unit BM1 as follows. The estimation unit 13 sets the cell voltage and the pack temperature acquired from any one of the battery management units BM2 to BMn that can communicate with the microcontroller MC1 as the cell voltage and the pack temperature acquired by the microcontroller MC1.

[0111] In other words, the estimation unit 13 substitutes the cell voltage and the pack temperature from the battery management unit BM1 with the cell voltage and the pack temperature from the other battery management units BM2 to BMn. Then, the estimation unit 13 estimates the pack temperature of the battery pack and the state of charge of the battery.

[0112] With such a configuration, even if the measurement results (the cell voltage and the pack temperature under the battery management unit BM1) cannot be obtained sufficiently, the battery management system 40 can estimate the pack temperature and the state of charge of the battery in order to control the charge and discharge.

[0113] Since the pack temperature depends on the ambient temperature, for example, a temperature difference occurs in the battery management units located at both ends of the battery. Therefore, it is preferable that the estimation unit 13 substitutes the cell voltage and pack temperature from the battery management unit BM1 with the cell voltage and pack temperature from the battery management unit BM2 arranged adjacent to the battery management unit BM1. By adopting such a configuration, the estimation unit 13 can more accurately estimate the cell voltage and pack temperature from the battery management unit BM1.

[0114] Here, the description has been made assuming that the wireless IC1 of the battery management unit BM1 is abnormal. The battery management system 40 can similarly estimate the cell voltage and pack temperature from the battery management units BM1 and BMn even when the wireless ICs 1 and ICn of the battery management units BM1 and BMn are abnormal. That is, when any one or a plurality of the wireless ICs 1 to ICn connected to the battery management units BM1 to BMn are abnormal, the battery management system 40 substitutes them with the cell voltage and pack temperature from the other battery management units BM2 to BMn with normal communication.

[0115] Of course, the graphs shown in FIGS. 5, 6, 8, 10, and 11 are merely examples shown schematically and are not limited to the shapes shown in each drawing.

[0116] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, it goes without saying that the present invention is not limited to the embodiments already described, and various modifications can be made without departing from the gist thereof.

[0117] In Embodiments 1 to 4, the configuration in which the microcontroller has each functional block such as the estimation unit 13 has been described. However, the present invention is not limited to this, and any configuration in which the battery management system includes each functional block may be used.

[0118] Furthermore, the present disclosure can be implemented by causing a CPU (Central Processing Unit) to execute a computer program for part or all of the processing of the battery management systems 10 to 40.

[0119] When the above-described program is loaded into a computer, it includes a set of instructions (or software code) for causing the computer to perform one or more functions described in the embodiments. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or tangible storage medium includes RAM (Random-Access Memory), ROM (Read-Only Memory), flash memory, SSD (Solid-State Drive), or other memory technologies, CD-ROM, DVD (Digital Versatile Disc), Blu-ray (registered trademark) disc, or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage, or other magnetic storage devices. The program may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, the transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

Explanation of Reference Numerals

[0120] 10, 20, 30, 40 Battery management systems 11 First communication connection confirmation unit 12 Second communication connection confirmation unit 13 Estimation unit 14 Control unit 15 Storage unit 16 First storage unit 17 Second storage unit 50 Discharge device 60 Charging device B1 Battery BM, BM1 to BMn Battery management unit BP1 Battery pack C1 Curve CU1 Control device G1 Charge state IC1 to ICn, IC101 Wireless IC IC100 Communication IC M1 Measurement unit MC1, MC2, MC3, MC4 Microcontroller P1 Point R1 Relay T1 to Tn Temperature sensor S1 to Sn Cell SI Current sensor SV Voltage sensor

Claims

1. A first communication connection confirmation unit that checks the communication state of a first communication connection connecting a microcontroller and a battery management unit that acquires the cell voltages of a plurality of cells and the pack temperature of a battery pack; A second communication connection confirmation unit that checks the communication state of a second communication connection connecting a microcontroller and a measurement unit that measures the pack voltage and pack current of a battery pack; A battery management system comprising an estimation unit that estimates charge / discharge information for controlling charge / discharge of a battery based on information that can be acquired by the microcontroller according to the communication states of the first communication connection and the second communication connection. A battery management system.

2. The charge / discharge information is the pack temperature and the state of charge of the battery. The battery management system according to claim 1.

3. Further comprising a control unit that controls charge / discharge of the battery, The control unit, Calculates the remaining time indicating the time until the state of charge reaches the state of charge in the discharge stop state or the charge stop state from the state of charge of the battery estimated by the estimation unit, Controls to continue discharging or charging during the remaining time. The battery management system according to claim 2.

4. The estimation unit, When the first communication connection is in a disconnected state and the second communication connection is in a disconnected state, Based on the temperature of the battery pack acquired by the microcontroller before the first communication connection is disconnected and the pack voltage acquired by the microcontroller before the second communication connection is disconnected, estimates the temperature of the battery pack and the state of charge of the battery. The battery management system according to claim 2.

5. The estimation unit, When the first communication connection is in a disconnected state and the second communication connection is in a communication state, Based on the pack voltage or the pack current, estimates the temperature of the battery pack and the state of charge of the battery. The battery management system according to claim 2.

6. The estimation unit, Determines whether the battery is in a standby state based on the pack current, When the battery is in a standby state, Based on the pack voltage, estimates the temperature of the battery pack and the state of charge of the battery. The battery management system according to claim 5.

7. Further comprising a first storage unit that stores correspondence information of the pack voltage, the state of charge of the battery, and the pack temperature, The estimation unit, Of the temperatures of the first memory unit, the temperature corresponding to the state of charge of the battery before the pack voltage and the first communication connection are disconnected is estimated as the pack temperature. The estimated pack temperature and the state of charge corresponding to the pack voltage are estimated as the state of charge of the battery. The battery management system according to claim 6.

8. The estimation unit: When the battery is in a charge / discharge state, Based on the pack current, the temperature of the battery pack and the state of charge of the battery are estimated. The battery management system according to claim 6.

9. Further comprising a second memory unit that stores the pack current and temperature changes, The estimation unit: For the pack temperature before the first communication connection is disconnected, the temperature obtained by correcting the temperature change corresponding to the pack current among the temperature changes of the second memory unit is estimated as the pack temperature. For the state of charge of the battery before the first communication connection is disconnected, the state of charge of the battery obtained by correcting the integrated value of the pack current is estimated as the state of charge of the battery. The battery management system according to claim 8.

10. The first communication connection is configured such that a plurality of the battery management units are connected to the microcontroller, The estimation unit: When a part of the connection between the microcontroller and the battery management unit in the first communication connection is in a disconnected state, The cell voltage and pack temperature acquired by the microcontroller from the battery management unit in the disconnected state from the microcontroller are regarded as the cell voltage and pack temperature acquired by the microcontroller from the battery management unit that can communicate with the microcontroller. The temperature of the battery pack and the state of charge of the battery are estimated. The battery management system according to claim 2.

11. The battery management unit capable of communicating with the microcontroller is a battery management unit arranged adjacent to the battery management unit in a disconnected state from the microcontroller. The battery management system according to claim 10.

12. Check the communication state of the first communication connection connecting the microcontroller and the battery management unit that acquires the cell voltage of a plurality of cells and the pack temperature of the battery pack. Check the communication state of the second communication connection connecting the microcontroller and the measurement unit that measures the pack voltage and pack current of the battery pack. Based on the information that can be obtained by the microcontroller according to the communication states of the first communication connection and the second communication connection, estimating charge / discharge information for controlling the charging and discharging of the battery. The computer executes the process. Battery management method.

13. Checking the communication state of the first communication connection connecting the microcontroller and the battery management unit that acquires the cell voltages of a plurality of cells and the pack temperature of the battery pack. Checking the communication state of the second communication connection connecting the microcontroller and the measuring unit that measures the pack voltage and pack current of the battery pack. Based on the information that can be obtained by the microcontroller according to the communication states of the first communication connection and the second communication connection, estimating charge / discharge information for controlling the charging and discharging of the battery. Causing the computer to execute the process. Program.

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