Battery management system, battery management method, and program

Abstract

The invention relates to a battery management system, a battery management method, and a program. The battery management system includes a first communication connection checking unit, a second communication connection checking unit, and an estimation unit. The first communication connection checking unit checks a communication state of a first communication connection connecting the microcontroller and the battery management unit, and the battery management unit obtains a battery cell voltage and a pack temperature. A second communication connection checking unit checks a communication state of a second communication connection connecting the microcontroller and a measuring unit that measures a group voltage and a group current. The estimation unit estimates charge / discharge information for controlling charge / discharge of the battery on the basis of information that can be obtained by the microcontroller MC1 in accordance with communication states of the first communication connection and the second communication connection.

Description

[0001] Cross - Reference to Related Applications

[0002] The disclosure of Japanese Patent Application No. 2023-211363, filed on December 14, 2023, including the specification, drawings, and abstract, is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to a battery management system, a battery management method, and a program. It relates to a battery management system, a battery management method, and a program suitable for estimating information for controlling discharge charge even when measurement results are not fully obtained. Background Art

[0004] In recent years, with the popularization of electric vehicles, the development of battery-related technologies has also been carried out. In a battery, the voltage of each battery cell, the temperature of the battery pack, the current of the battery pack, and the voltage of the battery pack are measured, and the state of charge is estimated based on the measurement results. Then, in the battery, for example, the charging / discharging of the battery is controlled to continue or abort according to the temperature or the state of charge. Summary of the Invention

[0005] In a battery, it is necessary to estimate information for controlling charging / discharging even when measurement results are not fully obtained. Other objects and novel features will become apparent from the description of this specification and the drawings.

[0006] The battery management system of the present disclosure includes: a first communication connection checking unit for checking a first communication state of a first communication connection connecting a microcontroller and a battery management unit, where the battery management unit obtains the battery cell voltage of a plurality of battery cells and the temperature of the battery pack; a second communication connection checking unit for checking a second communication state of a second communication connection connecting the microcontroller and a measurement unit that measures the voltage and current of the battery pack; and an estimation unit for estimating charging / discharging information for controlling the charging / discharging of the battery based on information that the microcontroller can obtain in response to the first communication state and the second communication state.

[0007] The battery management method according to the present disclosure is executed by a computer, and the method includes: checking a first communication state of a first communication connection connecting a microcontroller and a battery management unit, where the battery management unit obtains the battery cell voltage of a plurality of battery cells and the temperature of the battery pack; checking a second communication state of a second communication connection connecting the microcontroller and a measurement unit that measures the voltage and current of the battery pack; and estimating charging / discharging information for controlling the charging / discharging of the battery based on information that the microcontroller can obtain in response to the first communication state and the second communication state.

[0008] The program according to the present disclosure causes the CPU to execute the following processes: checking the communication state of a first communication connection connecting a microcontroller and a battery management unit, the battery management unit obtaining the cell voltages of a plurality of cells and the pack temperature of a battery pack; and checking the communication state of a second communication connection connecting the microcontroller and a measurement unit, the measurement unit being configured to measure the pack voltage and the pack current of the battery pack; and in response to the communication states of the first communication connection and the second communication connection, estimating charge / discharge information for controlling the charge / discharge of the battery based on the information that can be obtained by the microcontroller.

[0009] The present disclosure can provide a battery management system, a battery management method, and a program that can estimate information for controlling charge / discharge even if measurement results are not fully obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a block diagram showing a battery management system according to a first embodiment.

[0011] Figure 2 is a flowchart showing a battery management method according to a first embodiment.

[0012] Figure 3 is a block diagram showing a battery management system according to a second embodiment.

[0013] Figure 4 is a block diagram showing a battery management system according to a second embodiment.

[0014] Figure 5A is a diagram showing the relationship between the charge state of a cell and the cell voltage.

[0015] Figure 5B is a diagram showing the relationship between the charge state of a battery and the pack voltage.

[0016] Figure 6A is a diagram showing the change of the pack current in response to time.

[0017] Figure 6B is a diagram showing the change of the pack temperature in response to time.

[0018] Figure 6C is a diagram showing the relationship between the pack current and the pack temperature.

[0019] Figure 7 is a block diagram showing a battery management system according to a second embodiment.

[0020] Figure 8 is a diagram showing the relationship between the charge state of a battery and the pack voltage at each temperature.

[0021] Figure 9It is a block diagram showing a battery management system according to the third embodiment.

[0022] Figure 10 It is a graph showing the relationship between the state of charge of the battery and the pack voltage at each temperature.

[0023] Figure 11 It is a graph showing the relationship between the state of charge of the battery and the pack voltage at each temperature.

[0024] Figure 12 It is a block diagram showing a battery management system according to the fourth embodiment. Detailed Description of the Invention

[0025] 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 the drawings. In addition, the same elements are denoted by the same reference numerals and will not be described repeatedly.

[0026] In the following embodiments, when necessary for convenience, they will be described by dividing them into multiple sections or embodiments. However, unless otherwise specified, they are not mutually related, and one embodiment is related to some or all of the other embodiments as examples of modifications, applications, detailed descriptions, supplementary explanations, etc. In the following embodiments, the number of elements, etc. (including the number of elements, numerical values, quantities, ranges, etc.) is not limited to a specific number, but may be not less than or equal to a specific number, except in cases where the number is specifically indicated and clearly limited to a specific number in principle.

[0027] In addition, in the following embodiments, the constituent elements (including operation steps, etc.) are not necessarily essential, except in cases where they are specifically specified and in cases where they are clearly considered essential in principle. Similarly, in the following embodiments, when referring to the shape, positional relationship, etc. of components, etc., it is assumed that the shape, etc. is substantially approximate or similar to the shape, etc., except in cases where they are specifically specified and in cases where they are clearly considered obvious in principle. This also applies to the above-mentioned number, etc. (including number, numerical value, quantity, range, etc.).

[0028] (First Embodiment)

[0029] (Battery Management System)

[0030] Hereinafter, the configuration of the battery management system and the battery according to the first embodiment will be described with reference to the drawings. Figure 1 It is a block diagram showing a battery management system according to the first embodiment. As Figure 1 shown, the battery management system 10 includes a microcontroller MC1 and a battery management unit BM. In Figure 1In the exemplary embodiment shown, the microcontroller (MCU) MC1 includes a first communication connection checking unit (CCC1) 11, a second communication connection checking unit (CCC2) 12, and an estimation unit (ESTIMATION) 13. The measurement unit M1 is provided outside the battery management system 10.

[0031] As Figure 1 shown, 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.

[0032] In addition, as Figure 1 shown, 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.

[0033] The first communication connection is not limited to a wired connection and can be a wireless connection. The first communication connection checking unit 11 checks the communication status of the first communication connection. More specifically, the first communication connection checking unit 11 determines whether the communication status of the first communication connection is a disconnected state.

[0034] The second communication connection is a wired connection. The second communication connection checking unit 12 checks the communication status of the second communication connection. More specifically, the second communication connection checking unit 12 determines whether the communication status of the second communication connection is a disconnected state.

[0035] The battery management unit BM obtains the cell voltages of a plurality of battery cells and the pack temperature of the battery pack. The measurement unit M1 measures the pack voltage and pack current of the battery pack.

[0036] The microcontroller MC1 and the battery management unit BM communicate with each other through the first communication connection. Thus, the microcontroller MC1 obtains the cell voltages of the plurality of battery cells and the pack temperature of the battery pack obtained by the battery management unit BM.

[0037] In addition, the microcontroller MC1 and the measurement unit M1 communicate with each other through the second communication connection. Thus, the microcontroller MC1 obtains the pack voltage and pack current of the battery pack measured by the measurement unit M1.

[0038] That is, when the first communication connection and the second communication connection are in a communication state, the microcontroller MC1 obtains the cell voltages of a plurality of battery cells, the pack temperature, the pack voltage, and the pack current. 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 obtain the cell voltages of the plurality of battery cells and the pack temperature, but can obtain the pack voltage and the pack current. Therefore, depending on the communication status of the first communication connection and the second communication connection, the information that the microcontroller MC1 can obtain is different.

[0039] The estimation unit 13 estimates charge / discharge information for controlling charging / discharging of the battery based on information obtained by the microcontroller MC1 in response to the communication states of the first communication connection and the second communication connection.

[0040] That is, when the communication states of the first communication connection and the second communication connection are connected, the estimation unit 13 estimates charge / discharge information for controlling charging / discharging of the battery based on information from the communication state of the first communication connection or the second communication connection. 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 charging / discharging of the battery based on information obtained by the microcontroller before the communication states of the first communication connection and the second communication connection are disconnected.

[0041] Therefore, according to the communication states of the first communication connection and the second communication connection, the battery management system 10 according to the first embodiment estimates charge / discharge information for controlling charging / discharging of the battery based on information obtained by the microcontroller MC1. Therefore, the battery management system 10 can estimate information for controlling charging / discharging even when measurement results are not fully obtained.

[0042] (Battery management method)

[0043] Subsequently, the battery management method according to the first embodiment will be described. Figure 2 is a flowchart showing the battery management method of the first embodiment. The main components of each step are Figure 1 the first communication connection check unit 11, the second communication connection check unit 12, and the estimation unit 13 shown in

[0044] First, the first communication connection check unit 11 checks the communication state of the first communication connection connecting the microcontroller and the battery management unit, and the battery management unit obtains the cell voltages of a plurality of battery cells and the pack temperature of the battery pack (in step ST1).

[0045] Next, the second communication connection check unit 12 checks the communication state of the second communication connection connecting the microcontroller and the measurement unit, and the measurement unit measures the pack voltage and pack current of the battery pack (in step ST2).

[0046] Next, the estimation unit 13 estimates charge / discharge information for controlling charging / discharging of the battery based on information obtained by the microcontroller in response to the communication states of the first communication connection and the second communication connection (in step ST3).

[0047] Therefore, the battery management method according to the first embodiment estimates charge / discharge information for controlling charging / discharging of the battery based on information obtained by the microcontroller in response to the communication states of the first communication connection and the second communication connection. Therefore, the battery management method according to the first embodiment can estimate information for controlling charging / discharging even when measurement results are not fully obtained.

[0048] (Second Embodiment)

[0049] (Battery Configuration)

[0050] Hereinafter, the configuration of the battery management system and the battery according to the second embodiment will be described with reference to the drawings. Figure 3 and Figure 4 are block diagrams showing the battery management system according to the second embodiment. Figure 3 and Figure 4 The block diagrams shown in Figure 1 detail the block diagram shown in

[0051] As Figure 3 and Figure 4 shown, the battery management system 20 includes a microcontroller MC2 and battery management units BM1 to BMn. In Figure 3 and Figure 4 , the types of communication connections between the microcontroller MC2 and the battery management units BM1 to BMn are different, while other configurations are the same.

[0052] Figure 3 is a diagram showing a state where the microcontroller MC2 and the battery management units BM1 to BMn are wirelessly connected to each other. Figure 4 is a diagram showing a state where the microcontroller MC2 and the battery management units BM1 to BMn are wired to each other. A discharging device 50 or a charging device 60 is connected to the battery pack BP1 for charging or discharging.

[0053] As Figure 3 and Figure 4 shown, a controller CU1 is connected between the battery pack BP1 and the discharging device 50 or the charging device 60. The controller CU1 arbitrates between the battery pack BP1 and the discharging device 50 or the charging device 60. More specifically, the controller CU1 queries the corresponding device before charging and discharging to determine whether the discharging device 50, the charging device 60, and the battery management system 20 are operating correctly. Then, the controller CU1 requests the corresponding device to charge or discharge after checking that the discharging device 50, the charging device 60, and the battery management system 20 are operating correctly. Incidentally, if the discharging device 50 or the charging device 60 has an arbitration function, the controller CU1 may not be provided. In the embodiments to be described later, the configurations of the discharging device 50 or the charging device 60 and the controller CU1 are the same and will not be described again.

[0054] As shown in Figure 3 and Figure 4 shown, the microcontroller MC2 includes a first communication connection checking unit (CCC1) 11, a second communication connection checking unit (CCC2) 12, an estimation unit (ESTIMATION) 13, a control unit (CONTROL) 14, and a storage unit (STORAGE) 15.

[0055] The battery management units BM1 to BMn will be described below. As shown in Figure 3 shown, in the battery B1, a plurality of battery management units BM1 to BMn are included in the battery pack BP1. In addition, in the battery B1, a plurality of battery elements S1 to Sn are included in the battery pack BP1.

[0056] The plurality of battery elements S1 to Sn are distributed and connected to each of the battery management units BM1 to BMn. Accordingly, the battery management units BM1 to BMn obtain the cell voltages of the plurality of battery elements S1 to Sn. Hereinafter, the battery elements S1 to Sn are referred to as the battery elements S1 to Sn.

[0057] In addition, each of the temperature sensors T1 to Tn is 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. Accordingly, the battery management units BM1 to BMn obtain the pack temperature of the battery pack BP1.

[0058] Accordingly, the battery management units BM1 to BMn obtain the cell voltages of the plurality of battery elements S1 to Sn and the pack temperature of the battery pack BP1.

[0059] 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 Figure 3 the wireless connection shown in Figure 4 and may be a wired connection as shown in

[0060] That is, as shown in Figure 3 shown, the microcontroller MC2 and the battery management units BM1 to BMn are not limited to being wirelessly connected via the wireless ICs (integrated circuits) IC1 to ICn and the wireless IC IC101. As shown in Figure 4 shown, the microcontroller MC2 and the battery management units BM1 to BMn may be wired-connected via the communication IC 100.

[0061] Figure 3 and Figure 4 shown, the first communication connection checking unit 11 checks the communication state of the first communication connection. More specifically, the first communication connection checking unit 11 determines whether the communication state of the first communication connection is a disconnected state.

[0062] The measurement unit will be described. The measurement unit consists of a voltage sensor SV and a current sensor SI. As Figure 3 shown, the battery pack BP1 includes the voltage sensor SV and the 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.

[0063] The second communication connection will be described. The second communication connection connects the microcontroller MC2 and the voltage sensor SV and the current sensor SI. As Figure 3 and Figure 4 shown, the second communication connection is a wired connection.

[0064] Figure 3 and Figure 4 shown, the second communication connection checking unit 12 checks the communication state of the second communication connection. More specifically, the second communication connection checking unit 12 determines whether the communication state of the second communication connection is a disconnected state.

[0065] The microcontroller MC1 and the battery management unit BM1 communicate with each other through the first communication coupling. Therefore, the microcontroller MC1 obtains the cell voltages of the battery cells S1 to Sn and the pack temperature of the battery pack BP1.

[0066] In addition, the microcontroller MC1 and the measurement unit M1 communicate with each other through the second communication coupling. Therefore, the microcontroller MC1 obtains the pack voltage and the pack current of the battery pack BP1.

[0067] That is, when the first communication connection and the second communication connection are in a communication state, the microcontroller MC1 obtains the cell voltages of the plurality of battery 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.

[0068] (When the first communication connection and the second communication connection are connected)

[0069] Subsequently, the information stored in the storage unit 15 when the first communication connection and the second communication connection are in a communication state will be described. FIG. 5 is a diagram showing the relationship between the charging state of the battery cell and the cell voltage and the relationship between the charging state of the battery and the pack voltage.

[0070] The microcontroller MC2 obtains the cell voltage and the pack temperature. Therefore, as Figure 5A shown, the storage unit 15 stores the relationship between the charging state of the battery cell and the cell voltage at each temperature. In Figure 5A , three curves with different temperatures are shown. In Figure 5A , when the temperature becomes lower, even at the same charging state of the battery cell, the required cell voltage decreases.

[0071] The microcontroller MC2 obtains the pack voltage and the pack temperature. Accordingly, as shown in Figure 5B , the storage unit 15 stores the relationship between the charge state of the battery at each temperature and the pack voltage. In Figure 5B , three curves with different temperatures are shown. In Figure 5B , when the temperature becomes lower, even at the same charge state of the battery cell, the required pack voltage decreases.

[0072] The microcontroller MC2 obtains the pack temperature and the pack current. Accordingly, the storage unit 15 stores the relationship between the pack current and the change in the pack temperature during charging and discharging. FIG. 6 is a graph showing the change in the pack current with respect to time, the change in the pack temperature in response to time, and the relationship between the pack current and the change in the pack temperature.

[0073] As shown in Figure 6A and Figure 6B , the storage unit 15 stores the change in the pack current with respect to time and the change in the pack temperature with respect to time. The microcontroller MC2 uses the change in the pack current with respect to time shown in Figure 6A and the change in the pack temperature with respect to time shown in Figure 6B to calculate the relationship between the pack current and the change in the 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 the pack temperature shown in Figure 6C .

[0074] (Estimation of the Charge State of the Battery Cell and the Charge State of the Battery Pack)

[0075] Next, a method for estimating the charge state of the battery cell and the charge state of the battery of the estimation unit 13 when the first communication connection and the second communication connection are in a communication state will be described.

[0076] The microcontroller MC2 obtains the battery cell voltage / pack temperature of the battery cell. The estimation unit 13 uses Figure 5A to estimate the charge state of the battery cell based on the battery cell voltage and the pack temperature obtained by the microcontroller MC2.

[0077] More specifically, it will be described. The estimation unit 13 specifies the curve having the pack temperature obtained by the microcontroller MC2 among the curves in Figure 5A . Then, the estimation unit 13 determines the charge state of the battery cell having the battery cell voltage obtained by the microcontroller MC2 according to the curve. In this way, the estimation unit 13 estimates the charge state of the battery cell.

[0078] The microcontroller MC2 obtains the pack temperature and the pack voltage of a plurality of battery cells. The estimation unit 13 uses Figure 5BEstimate the state of charge of the battery pack BP1 based on the pack voltage and pack temperature obtained by the microcontroller MC2.

[0079] More specifically, it will be described. The estimation unit 13 identifies the curve having the pack temperature obtained by the microcontroller MC2 among the curves in Figure 5B . Then, the estimation unit 13 specifies the state of charge of the battery B1 having the pack voltage obtained by the microcontroller MC2 according to the curve. Therefore, the estimation unit 13 estimates the state of charge of the battery B1.

[0080] Therefore, in the battery management system 20, the storage unit 15 stores the information in Figure 5A 、 Figure 5B and Figures 6A - 6C . Therefore, when the first communication connection and the second communication connection are in a communication state, the battery management system 20 can estimate the state of charge of the battery element or the state of charge of the battery B1 based on the information in the storage unit 15. The storage unit 15 can store the state of charge of the battery B1 and the pack temperature associated with time.

[0081] (When the first communication connection and the second communication connection are disconnected)

[0082] Subsequently, the first communication connection and the second communication connection will be described in the case of the disconnected state. Figure 5A and Figure 5B The storage unit 15 shown in stores the relationship between the state of charge of the battery element and the battery element voltage at each temperature, and stores the relationship between the state of charge of the battery and the pack voltage at each temperature. Here, the configuration of the battery, the estimation unit 13, and the method of estimating the pack temperature and the state of charge of the battery will be described in sequence.

[0083] First, the configuration of the battery when the first communication connection and the second communication connection are disconnected will be described. If the first communication connection is disconnected, this includes the case where the wireless IC IC101 connected to the microcontroller or all the wireless ICs IC1 to ICn connected to the battery management units BM1 to BMn are abnormal. In addition, when the second communication connection is in a disconnected state, it includes the case where the voltage sensor SV and the current sensor SI have failed. Incidentally, when the first communication connection and the second communication connection are in a disconnected state, it includes the case where communication data is corrupted.

[0084] Figure 7 is a block diagram showing the battery management system according to the second embodiment. As shown in Figure 7 , since the first communication connection is in a disconnected state, the connection (first communication connection) of the wireless ICs (WL IC) IC1 to ICn and the wireless IC (WL IC) IC101 is shown by a dotted line. In addition, as shown in Figure 7As shown, since the second communication connection is in a disconnected state, its connection (second communication connection) between the microcontroller MC2 and the voltage sensor SV and the current sensor SI is shown by a dashed line.

[0085] In Figure 7 the configuration of the battery B1 shown in, other configurations except for the connection states of the first communication connection and the second communication connection are the same as those in Figure 3 the configuration. In the following description, the estimation unit 13 estimates the group temperature and the state of charge of the battery B1 as charge release information for controlling the charge release of the battery.

[0086] When the first communication connection is in a cut-off state and the second communication connection is in a disconnected state, the estimation unit 13 estimates the group temperature and the state of charge of the battery B1 as follows.

[0087] The estimation unit 13 estimates the group temperature and the state of charge of the battery B1 based on the group temperature obtained by the microcontroller MC2 before the first communication connection is disconnected and the group voltage obtained by the microcontroller MC2 before the second communication connection is disconnected.

[0088] A more specific description thereof will be given below in conjunction with Figure 5B The storage unit 15 stores Figure 5B the relationship between the state of charge of the battery and the group voltage at each temperature shown in. The estimation unit 13 identifies the curve having the group temperature obtained by the microcontroller MC2 among the curves in Figure 5B . Then, the estimation unit 13 specifies the state of charge of the battery B1 having the group voltage obtained by the microcontroller MC2 according to this curve.

[0089] Therefore, by using the group temperature obtained by the microcontroller MC2 before the first communication connection is disconnected and the group voltage obtained 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. In addition, the estimation unit 13 estimates the group temperature obtained by the microcontroller MC2 as the temperature of the battery pack BP1 before the first communication connection is disconnected.

[0090] Therefore, even when the first communication connection and the second communication connection are in a disconnected state and the measurement results (battery cell voltage, group temperature, group voltage, and group current) are not fully obtained, the battery management system 20 can estimate the group temperature and the state of charge of the battery B1.

[0091] Here, the estimation unit 13 estimates the pack temperature and the state of charge of the battery based on the pack temperature obtained by the microcontroller MC1 before the first communication connection is disconnected and the pack voltage obtained by the microcontroller MC2 before the second communication connection is disconnected. Since the microcontroller MC2 periodically stores the pack temperature and the state of charge in the storage unit 15, the estimation unit 13 can estimate the temperature stored in the microcontroller MC1 as the pack temperature before the first communication connection is disconnected. In addition, the estimation unit 13 can estimate that the state of charge stored in the microcontroller MC1 is the state of charge of the battery before the first communication connection and the second communication connection are disconnected.

[0092] (Example of control)

[0093] Here, the control unit 14 will be described with reference to Figure 3 and Figure 8 Figure. Figure 8 is a graph showing the relationship between the state of charge of the battery and the pack voltage at each temperature. The control unit 14 controls the continuation of discharging or charging according to the temperature estimated by the estimation unit 13 and the state of charge of the battery B1. Additionally, when the temperature and the state of charge of the battery B1 estimated by the estimation unit 13 exceed a predetermined value, the control unit 14 controls Figure 3 the relay B1 and cuts off the charging / discharging of the battery R1.

[0094] In Figure 8 Figure, the point P1 determined according to the pack temperature and the state of charge of the battery B1 estimated by the estimation unit 13 is shown. In Figure 8 Figure, the state of charge in the charging stop state or the discharging stop state is shown by a dotted line. When the battery B1 is charging, the point P1 moves to the right along the curve to the charging stop condition. When the battery B1 is discharging, the point P1 moves to the left along the curve so as to face the discharging stop condition.

[0095] The control unit 14 calculates the remaining time indicating the time from the state of charge of the battery (point P1) estimated by the estimation unit 13 until the state of charge in the discharging stop state or the charging stop state. With reference to Figure 8 Figure, the case of charging is described in detail as an example.

[0096] As Figure 8 Figure shows, if the state of charge of the charging stop state is 70% and the state of charge of the point P1 is 50%, the control unit 14 determines that there is still 20% of the remaining charge until it reaches the charging stop state. The control unit 14 calculates the remaining time indicating the time from the remaining charge until the charging stop state by dividing the remaining charge amount by a predetermined pack current. The predetermined pack current is, for example, the maximum charging current. This also applies to discharging. Then, the control unit 14 controls the continuation of discharging or charging during the remaining time.

[0097] Therefore, the battery management system 20 according to the second exemplary embodiment calculates the remaining time indicating the time from the state of charge of the battery estimated by the estimation unit 13 to the discharge stop state or the charge stop state. Then, the battery management system 20 controls the continuation of discharge or charge within the remaining time. The method of controlling the discharge or charge of such a battery is the same as that in the third and fourth embodiments described below.

[0098] With this configuration, when the first communication connection and the second communication connection are disconnected, the battery management system 20 can continuously charge and discharge the battery for a specific period. For example, when the battery B1 using the battery management system 20 is installed in an electric vehicle, the following method can be utilized.

[0099] Even when the first communication connection and the second communication connection are in a disconnected state, the control unit 14 controls the relay R1 such that the estimation unit 13 continues to discharge or charge according to the estimated temperature and the state of charge of the battery, without interrupting the charging and discharging of the battery B1. Therefore, a specific time for the electric vehicle in motion to drive to one side of the lane can be ensured. That is, when a battery using the battery management system 20 is installed in an electric vehicle, a degradation operation of the electric vehicle can be achieved.

[0100] Here, the control unit 14 calculates the remaining time by dividing the remaining charge amount by a predetermined set current. Then, the control unit 14 is described as controlling the continuation of discharge or charge during the calculated remaining time. However, it is not limited thereto, and the control unit 14 can be allowed to continue discharging or charging during the time obtained by shortening the calculated remaining time. With such a configuration, the control unit 14 can be controlled to continue discharging or charging more safely.

[0101] In Figure 8 , the maximum temperature of the pack temperature of the battery pack BP1 is shown. Generally, the pack temperature increases with charging / discharging. When the pack temperature estimated by the estimation unit 13 becomes the highest temperature or higher, the control unit 14 controls Figure 3 the relay R1 and cuts off the charging and discharging of the battery. Therefore, safety can be ensured.

[0102] Here, the battery cells in the battery pack tend to increase in order to increase the capacity and efficiency of the battery. As the number of battery cells increases, when the battery management unit increases, the communication lines between the battery management unit and the communication IC ( Figure 3 ) increase.

[0103] However, compared with Figure 4 , in Figure 3 , since the first communication connection is a wireless connection, such a problem can be solved. In addition, as in Figure 3As shown, 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. In addition, as Figure 3 shown, when the first communication connection is a wireless connection, there is no need to redesign the communication line path during battery layout. Additionally, as Figure 3 shown, when the first communication connection is a wireless connection, since the space for the communication line can be allocated to the space for battery cells, the capacity of the battery cells can be increased.

[0104] (Third Embodiment)

[0105] (When the first communication connection is disconnected and the second communication connection is in communication)

[0106] Next, the configuration of the battery management system and the battery according to the third embodiment will be described. Figure 9 is a block diagram showing the battery management system according to the third embodiment. The battery management system 30 includes a microcontroller MC3 and battery management units BM1 to BMn. The microcontroller MC3 includes a first communication connection check unit (CCC1) 11, a second communication connection check unit (CCC2) 12, an estimation unit (ESTIMATION) 13, a control unit (CONTROL) 14, a first storage unit (STORAGE1) 16, and a second storage unit (STORAGE2) 17.

[0107] Figure 9 The first communication connection check unit 11, the second communication connection check unit 12, and the control unit 14 shown in

[0108] are the same as those in the second embodiment, and thus their descriptions will be omitted. Hereinafter, the configuration of the battery, the first storage unit 16, the second storage unit 17, and the estimation unit 13 will be described in this order in detail. Figure 9 First, the configuration of the battery will be described. In

[0109] the first communication connection is in a disconnected state, and since the second communication connection is in a communication state, the connection (first communication connection) between the wireless ICs IC1 to ICn and the wireless IC IC101 is shown by a dashed line. Figure 5A and Figure 5B 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 battery 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 as shown in Figure 5A and Figure 5B . That is, the first storage unit 16 stores the corresponding information of the cell voltage, the charge state of the battery cell, and the pack temperature (in Figure 5A ), and the corresponding information of the pack voltage, the charge state of the battery, and the pack temperature (in Figure 5B ).

[0110] The second storage unit 17 stores Figures 6A - 6C the change of the group current with respect to time, the change of the group temperature with respect to time, and the relationship between the group current and the change of the group temperature shown in FIG. The first storage unit 16 and the second storage unit 17 periodically store the group temperature, the charging state of the battery element, and the charging state of the battery obtained by the microcontroller MC3.

[0111] As Figure 9 shown in FIG., since the second communication connection is in a communication state, the microcontroller MC3 can obtain the group current. Therefore, when the microcontroller MC3 detects that current is flowing, the microcontroller MC3 can detect that the battery B1 is in a charging state. On the other hand, if the microcontroller MC3 detects that no current is flowing, the microcontroller MC3 can detect that the battery is idle.

[0112] Hereinafter, the estimation unit 13 will be described separately from the case where the battery is in a sleep state and the case where the battery is in a charging state. In the following description, the estimation unit 13 will be described as estimating the group temperature and the charging state of the battery as charging information for controlling the discharge and charge of the battery.

[0113] (When the battery is in a sleep state)

[0114] When the battery is in a sleep state, the method by which the estimation unit 13 estimates the temperature and the charging state will be described. First, the method by which the estimation unit 13 estimates the temperature based on the information stored in the first storage unit 16 ( Figure 5B shown in FIG.) will be described.

[0115] As Figure 9 shown in FIG., the microcontroller MC3 can obtain the group voltage because the second communication connection is in a communication state. The first storage unit 16 stores the charging state of the battery that the microcontroller MC3 has obtained before the first communication connection is disconnected.

[0116] Thus, the estimation unit 13 estimates the group temperature by using the relationship between the charging state at each temperature and the group voltage stored in the first storage unit 16 ( Figure 5B shown in FIG.). A more specific description thereof will be made with reference to Figure 10 FIG. Figure 10 FIG. is a diagram showing the relationship between the charging state of the battery and the group voltage at each temperature. Figure 10 Same as Figure 5B FIG. and is an explanatory diagram for more detailedly explaining the estimation unit 13.

[0117] As Figure 10As shown in the figure, the estimation unit 13 may estimate, among the temperatures of the first storage unit 16, the temperature corresponding to the pack voltage and the state of charge of the battery immediately before the first communication connection is disconnected (immediately before going to sleep) as the pack temperature. In other words, as Figure 10 shown in the figure, the estimation unit 13 estimates the temperature of curve C1 that satisfies both the pack voltage and the state of charge of the battery immediately before the first communication connection is disconnected (immediately before going to sleep) as the pack temperature.

[0118] 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. In addition, since the second communication connection is in a communication state, the microcontroller MC3 can obtain the pack voltage.

[0119] Therefore, the estimation unit 13 can estimate the state of charge of the battery by using the relationship between the state of charge and the pack voltage at each temperature stored in the first storage unit 16 ( Figure 5B in the figure). A more specific description will be given with reference to Figure 11 . Figure 11 is a diagram showing the relationship between the state of charge of the battery cells and the pack voltage at each temperature. Figure 11 Same as Figure 5B , it is an explanatory diagram for more detailed explanation of the estimation unit 13.

[0120] As Figure 11 shown in the figure, the estimation unit 13 may estimate the state of charge corresponding to the estimated pack temperature and the pack voltage obtained by the microcontroller MC3 as the state of charge of the battery. In other words, as Figure 11 shown in the figure, the estimation unit 13 estimates the state of charge G1 having the pack voltage obtained by the microcontroller MC3 from curve C1 of the estimated pack temperature as the state of charge of the battery.

[0121] Therefore, when the battery is in a sleep state, the battery management system 30 can estimate the pack temperature and the state of charge of the battery even if the measurement results (battery cell voltage, pack temperature) are not fully obtained, so as to control charging / discharging.

[0122] Incidentally, as time elapses from the timing when the battery becomes idle, the pack temperature changes with the ambient temperature. Therefore, the estimation unit 13 estimates the pack temperature by using Figure 10 and estimates the state of charge of the battery. With such a configuration, even when the battery changes from the temperature and state of charge at the timing when the battery is in a sleep state, the battery management system 30 can accurately estimate the pack temperature and the state of charge of the battery.

[0123] (When the battery is in a discharged state)

[0124] When the battery is in a charging / discharging state, a method for the estimation unit 13 to estimate the temperature and the state of charge 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 ( Figure 6C will be described. Since the second communication connection is in a communication state, the microcontroller MC3 can obtain the pack current. The second storage unit 17 stores the pack temperature obtained by the microcontroller MC3 before the first communication connection is disconnected.

[0125] Therefore, the estimation unit 13 can use the relationship between the pack current stored in the second storage unit 17 and the change in the pack temperature ( Figure 6C to estimate the change in the pack temperature according to the pack current. Then, the estimation unit 13 estimates the temperature obtained by correcting the estimated temperature change with respect to the pack temperature before the first communication connection is disconnected as the pack temperature.

[0126] 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 23 degrees as the pack temperature.

[0127] Next, a method for the estimation unit 13 to estimate the state of charge will be described. Since the second communication connection is in a communication state, the microcontroller MC3 can obtain the pack current. The second storage unit 17 stores the state of charge obtained by the microcontroller MC3 before the first communication connection is disconnected.

[0128] Here, the microcontroller MC1 measures the time. Therefore, the estimation unit 13 can calculate the integral value of the current by multiplying the time by the pack current. Thus, the estimation unit 13 estimates the state of charge obtained by correcting the integral value of the pack current with respect to the state of charge of the battery before the first communication connection is disconnected as the state of charge of the battery.

[0129] Therefore, when the battery is in a charging / discharging state, even if the measurement results (battery cell voltage, pack temperature) are not fully obtained, the battery management system 30 can estimate the pack temperature and the state of charge of the battery in order to control the charging / discharging.

[0130] 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. This allows the battery management system 30 to estimate the pack temperature and the state of charge of the battery to control the charging / discharging even if the measurement results are not fully obtained.

[0131] (When the first communication connection is in a communication state and the second communication connection is in a disconnected state)

[0132] When the first communication connection is in a communication state and the second communication connection is in a disconnected state, the microcontroller MC1 cannot obtain the pack voltage and pack current. On the other hand, since the first communication connection is in a communication state, the microcontroller MC1 can obtain the cell voltage and pack temperature.

[0133] Accordingly, the estimation unit 13 can estimate the state of charge of the battery cell based on the information in the first storage unit 16. Figure 5A More specifically, the estimation unit 13 specifies the curve having the pack temperature obtained by the microcontroller MC3 among the curves of Figure 5A . Then, the estimation unit 13 estimates the state of charge of the battery cell having the cell voltage obtained by the microcontroller MC3 as the state of charge of the battery cell according to this curve.

[0134] Then, the estimation unit 13 estimates the state of charge of the battery based on the state of charge of the battery cell. More specifically, when the battery is in a charging state, the estimation unit 13 estimates the highest state of charge among the states of charge of the battery cells as the state of charge of the battery. In addition, when the battery is in a discharging state, the estimation unit 13 estimates the lowest state of charge among the states of charge of the battery cells as the state of charge of the battery.

[0135] Incidentally, the estimation unit 13 estimates the state of charge of the battery cell at a predetermined time interval. Therefore, the estimation unit 13 can estimate the pack current by dividing the state of charge obtained by subtracting the state of charge of the battery cell after a predetermined time has elapsed from the state of charge of the battery cell before a predetermined time has elapsed by the predetermined time.

[0136] (Fourth Embodiment)

[0137] (When the connection between the microcontroller and the battery management section is disconnected)

[0138] Next, the configuration of the battery management system and the battery according to the fourth embodiment will be described. Figure 12 is a block diagram showing a battery management system according to the fourth embodiment. The battery management system 40 includes a microcontroller MC4 and battery management units BM1 to BMn. The microcontroller MC4 includes a first communication connection check unit (CCC1) 11, a second communication connection check unit (CCC2) 12, and an estimation unit (ESTIMATION) 13.

[0139] Figure 12 The first communication connection check unit 11 and the second communication connection check unit 12 shown in are the same as those in the first to third embodiments, and thus their descriptions will be omitted. Hereinafter, the configuration of the battery and the estimation unit 13 will be described in detail in order. Although Figure 12 is not shown, the microcontroller MC4 may include the same control unit as in the second and third embodiments.

[0140] First, the configuration of the battery will be described. If some of the connections in the connections between the microcontroller MC4 and the battery management units BM1 to BMn are disconnected, the wireless IC101 connected to the microcontroller is normal and some of the wireless ICs IC1 to ICn connected to the battery management units BM1 to BMn are abnormal.

[0141] In Figure 12 As the wireless IC IC1 of the battery management unit BM1 is abnormal and the connection (a part of the first communication connection) between the microcontroller MC4 and the battery management unit BM1 is disconnected, the wireless IC IC1 is indicated by a dashed line. In the following description, the estimation unit 13 is described as estimating the group temperature and the charging state of the battery as the charge / discharge information for controlling the charge / discharge of the battery.

[0142] Since the connection (a part of the first communication connection) between the wireless IC IC1 and the wireless IC IC101 is disconnected, the microcontroller MC4 cannot obtain the cell voltage and the group temperature in the battery management unit BM1.

[0143] In this case, the estimation unit 13 estimates the cell voltage and the group temperature obtained by the microcontroller MC4 from the battery management unit BM1 in the following manner. The estimation unit 13 determines the cell voltage and the group temperature obtained by the microcontroller MC1 as the cell voltage and the group temperature obtained by any of the battery management units BM2 to BMn that can be communicatively connected to the microcontroller MC1.

[0144] In other words, the estimation unit 13 replaces the cell voltage and the group temperature from the battery management unit BM1 with the cell voltage and the group temperature from the other battery management units BM2 to BMn. Then, the estimation unit 13 estimates the group temperature of the battery pack and the charging state of the battery.

[0145] With such a configuration, even if the measurement results (the cell voltage and the group temperature under the battery management unit BM1) are not fully obtained, the battery management system 40 can estimate the group temperature and the charging state of the battery in order to control the charge / discharge.

[0146] Since the group temperature depends on the ambient temperature, for example, a temperature difference appears in the battery management sections located at both ends of the battery. Therefore, it is preferable that the estimation unit 13 replaces the cell voltage and the group temperature from the battery management unit BM1 with the cell voltage and the group temperature from the battery management unit BM2 provided adjacent to the battery management unit BM1. With such a configuration, the estimation unit 13 can more accurately estimate the cell voltage and the group temperature from the battery management unit BM1.

[0147] Here, the wireless IC1 of the battery management unit BM1 is explained as abnormal. Even if the wireless ICs IC1 to ICn of the battery management units BM1 to BMn are abnormal, the battery management system 40 can similarly estimate the cell voltages and the pack temperatures from the battery management units BM1 to BMn. That is, when any one or more of the wireless ICs IC1 to ICn connected to the battery management units BM1 to BMn are abnormal, the battery management system 40 substitutes the cell voltages and the pack temperatures from the other battery management units BM2 to BMn whose communication is normal.

[0148] It should be understood that the graphs shown in FIGS. 5 and 6, Figure 8 , Figure 10 and Figure 11 are merely examples shown schematically and are not limited to the shapes shown in the respective figures.

[0149] Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the embodiments that have been described, and it goes without saying that various modifications can be made without departing from its gist.

[0150] From the first to the fourth embodiments, each functional block such as the estimation unit 13 has been described as a configuration of a microcontroller. However, the present invention is not limited to this, and the configuration may be such that each functional block is provided in the battery management system.

[0151] In addition, some or all of the processes in the battery management systems 10 to 40 can be implemented by causing a CPU (Central Processing Unit) to run a computer program.

[0152] The above program includes an instruction set (or software code) for causing a computer to execute one or more functions described in the embodiments when read into the computer. The program can be stored on a non-temporary computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or the 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 tape cassette, magnetic tape, magnetic disk storage or other magnetic storage devices. The program can be transmitted on a temporary computer-readable medium or a communication medium. By way of example and not limitation, the temporary computer-readable medium or the communication medium includes electrical, optical, acoustic or other forms of propagated signals.

Claims

1. A battery management system, comprising: Microcontroller; A battery management unit, used to obtain battery cell voltages of a plurality of battery cells and a battery pack temperature; A measuring unit, used for measuring a pack voltage and a pack current of the battery pack; a first communication connection checking unit, configured to check a first communication state of a first communication connection connecting the microcontroller and the battery management unit; a second communication connection checking unit, configured to check a second communication state of a second communication connection connecting the microcontroller and the measuring unit; as well as An estimating unit for estimating charge / discharge information for controlling charge / discharge of the battery pack based on information obtained by the microcontroller in response to the first communication state and the second communication state.

2. The battery management system according to claim 1, The charging / discharging information includes the group temperature and charging state of the battery group.

3. The battery management system according to claim 2, further comprising a control unit for controlling the charging / discharging of the battery pack, wherein the control unit calculates a remaining time indicating a time taken to reach a charging state from a discharge stop state or a charge stop state based on the charge / discharge information estimated by the estimation unit, and controls to continue discharging or charging during the remaining time.

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

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

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

7. The battery management system according to claim 6, further comprising a first storage unit storing corresponding information of the group voltage, the group temperature and the charging state of the battery group, wherein the estimation unit estimates the group temperature based on a temperature among the temperatures in the first storage unit that corresponds to the group voltage and the charge state of the battery group before the first communication connection is disconnected, wherein the estimation unit estimates the state of charge of the battery pack based on a state of charge corresponding to the estimated pack temperature and the estimated pack voltage.

8. The battery management system according to claim 6, in, The estimation unit estimates the pack temperature and the charge state of the battery pack based on the pack current when the battery pack is in the charge / discharge state.

9. The battery management system according to claim 8, further comprising a second storage unit storing the group current and temperature changes, wherein the estimation unit estimates the group temperature based on a temperature obtained by correcting a temperature change corresponding to the group current among the temperature changes in the second storage unit with respect to the group temperature before the first communication connection is disconnected, wherein the estimation unit estimates the charge state of the battery pack based on a charge state of the battery pack obtained by correcting an integrated value of the pack current with respect to a charge state of the battery before the first communication connection is disconnected.

10. The battery management system according to claim 2, wherein the first communication connection is configured by connecting a plurality of the battery management units to the microcontroller, in, When part of the connection between the microcontroller and the multiple battery management units is disconnected in the first communication connection, the estimation unit estimates the group temperature and the charging state of the battery group based on the battery cell voltage and the group temperature obtained by the microcontroller from the battery management unit that is disconnected from the microcontroller, and the battery cell voltage and the group temperature are the battery cell voltage and the group temperature obtained by the microcontroller from the battery management unit that is communicatively connected to the microcontroller.

11. The battery management system according to claim 10, The battery management unit is communicatively connected to the microcontroller and is arranged adjacent to the battery management unit that is disconnected from the microcontroller.

12. A battery management method for the battery management system according to claim 1, the battery management method comprising the following steps: checking a communication state of a first communication connection connecting the microcontroller and a battery management unit, the battery management unit obtaining a battery cell voltage of a plurality of battery cells and a pack temperature of a battery pack; checking a communication state of a second communication connection connecting the microcontroller and a measuring unit, the measuring unit being used to measure a pack voltage and a pack current of the battery pack; as well as In response to the communication states of the first communication connection and the second communication connection, charge / discharge information for controlling charge / discharge of the battery pack is estimated based on information obtainable by the microcontroller.

13. A program comprising program instructions for causing a computer to execute the battery management method according to claim 12.

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