Battery system and parallel group control method using same

Abstract

Provided are a battery system and a parallel group control method using the same, the system including: a plurality of battery packs connected in parallel with each other; a plurality of switches connected in series to one of both ends of each of the plurality of battery packs, for each of the plurality of battery packs; a battery monitoring integrated circuit (BMIC) acquiring state information of a plurality of pack voltages including the plurality of battery packs; and a main control unit (MCU) that generates a plurality of candidate groups including at least one battery pack among the plurality of battery packs based on the plurality of group voltages, estimates a capacity of each of the plurality of battery packs based on the state information, determining one final connection group to perform the power operation among the plurality of candidate groups based on the capacity of each of the plurality of battery packs, and transmitting, to the BMIC, a group control signal for turning on a switch connected to a battery pack belonging to the final connection group among the plurality of switches.

Description

Technical Field

[0001] CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0147905 filed in the Korean Intellectual Property Office on November 8, 2022, and Korean Patent Application No. 10-2023-0073573 filed in the Korean Intellectual Property Office on June 8, 2023, and all contents disclosed in the files of the Korean patent applications are incorporated as a part of this specification.

[0003] The invention relates to a battery system and a parallel group control method using the battery system. Background Art

[0004] In a system where battery packs are connected in parallel to each other, one combination of the plurality of battery packs may be selected and operated in parallel. The state of charge (SOC) of each of the plurality of battery packs may be considered in order to find a combination of battery packs operated in parallel.

[0005] However, there are cases where it is difficult to fully express the performance of a battery pack with SOC alone. For this reason, there are cases where a battery device in which battery packs are connected in parallel with each other combined only in consideration of SOC fails to exhibit optimal performance. Summary of the invention

[0006] [Technical issues]

[0007] The present disclosure seeks to provide a battery system including a plurality of battery packs, that is, a battery system in which a combination of battery packs to be operated in parallel with each other is determined among the plurality of battery packs and the determined combination of packs is connected in parallel with each other, and a parallel pack control method.

[0008] [Technical solution]

[0009] According to one embodiment, a battery system is provided, comprising: a plurality of battery packs connected in parallel to each other; a plurality of switches, for each battery pack in the plurality of battery packs, the plurality of switches being connected in series to one of the two ends of each battery pack; a battery monitoring integrated circuit (BMIC), the battery monitoring integrated circuit acquiring status information of a plurality of group voltages including the plurality of battery packs; and a main control unit (MCU), the main control unit generating a plurality of candidate groups including at least one battery pack among the plurality of battery packs based on the plurality of group voltages, estimating a capacity of each of the plurality of battery packs based on the status information, determining a final connection group for performing power operations among the plurality of candidate groups based on the capacity of each of the plurality of battery packs, and sending a group control signal to the BMIC for turning on switches among the plurality of switches connected to the battery pack belonging to the final connection group.

[0010] The MCU can sort the multiple battery groups in order of highest group voltage, and based on the sorting order, determine a group of battery groups among the multiple battery groups that have a group voltage as a reference group or smaller and a voltage deviation from the group voltage of the reference group of a predetermined reference voltage or smaller as a candidate group by using each of the multiple battery groups as a reference group.

[0011] The MCU may estimate, for each battery pack of the plurality of battery packs, a state of charge (SOC) and a state of health (SOH) of the battery pack, and, for each battery pack of the plurality of battery packs, estimate a capacity of each battery pack of the plurality of battery packs based on the SOC and SOH of the battery pack.

[0012] The MCU may derive a capacity as a total capacity of at least one battery pack belonging to each candidate group among the plurality of candidate groups based on the capacity of each battery pack of the plurality of battery packs.

[0013] The MCU may determine a final connection group among multiple candidate groups based on the total capacity.

[0014] When receiving a group control signal from the MCU, the BMIC can send a signal to multiple switches by generating a switch control signal, which is used to close a first switch among the multiple switches connected to at least one battery group belonging to the final connection group and open the remaining switches among the multiple switches except the first switch.

[0015] The MCU can determine available battery groups among multiple battery groups, sort the available battery groups in order of highest group voltage, and based on the sorting order, determine a group of battery groups among the multiple available battery groups that have a group voltage as a reference group or smaller and a voltage deviation from the group voltage of the reference group of a predetermined reference voltage or smaller as a candidate group by using each available battery group in the available battery groups as a reference group.

[0016] According to another embodiment, a parallel group control method is provided, including: a battery management system (BMS) receiving a signal indicating that a vehicle is in a driving mode from a vehicle control unit (VCU); the BMS grouping a plurality of candidate groups based on the group voltage of each battery group in a plurality of battery groups connected in parallel with each other, each candidate group including at least one battery group among the plurality of battery groups; the BMS estimating, for each battery group among the plurality of battery groups, a state of charge (SOC) and a state of health (SOH) of the battery group, and the BMS estimating, for each battery group among the plurality of battery groups, a capacity of each battery group based on the SOC and SOH of the battery group; and the BMS determining, from the plurality of candidate groups, a final connection group based on the capacity of each battery group of the plurality of battery groups.

[0017] Grouping multiple candidate groups may include: sorting the multiple battery groups in order of highest group voltage; and based on the sorting order, determining a group including battery groups among the multiple battery groups that have a group voltage as a reference group or less and a voltage deviation from the group voltage of the reference group of a predetermined reference voltage or less as a candidate group by using each of the multiple battery groups as a reference group.

[0018] Determining a final connection group among multiple candidate groups may include: deriving a capacity as a total capacity of at least one battery pack belonging to each of the multiple candidate groups based on the capacity of each of the multiple battery packs, and determining a final connection group among the multiple candidate groups based on the total capacity.

[0019] The method may also include: generating a switch control signal by the BMS, the switch control signal being used to close a first switch connected to a battery pack belonging to a final connection group among a plurality of switches connected in series to one of the two ends of each battery pack, and being used to open the remaining switches except the first switch among a plurality of switches for each of the plurality of battery packs, and sending the switch control signal by the BMS to the plurality of switches.

[0020] Grouping of multiple candidate groups may include: determining available battery groups among multiple battery groups, sorting the available battery groups in order of highest group voltage, and based on the sorting order, determining a group including battery groups among the multiple available battery groups that have a group voltage as a reference group or less and a voltage deviation from the group voltage of the reference group of a predetermined reference voltage or less as a candidate group by using each available battery group in the available battery groups as a reference group.

[0021] [Beneficial Effects]

[0022] The combination of groups to be connected in parallel to each other may be determined in consideration of the amount of energy of each of the plurality of battery groups, thereby ensuring that the battery system including them has maximum energy.

[0023] The battery capacity may be estimated in consideration of not only the state of charge (SOC) but also the state of health (SOH) of each of the bank combinations to be connected in parallel to each other, thus having the optimal bank combination determined in consideration of the deviation between the SOHs.

[0024] Even when each of a plurality of battery packs deteriorates differently, the driving mileage of the vehicle can be improved by connecting a battery system in which an optimum combination of packs is connected in parallel to each other to the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a view showing a battery system according to one embodiment.

[0026] Figure 2 yes Figure 1 Detailed configuration view of the main control unit (MCU) shown in .

[0027] Figure 3 is a flow chart of a parallel group control method according to another embodiment.

[0028] Figure 4 is a table showing examples of a pack voltage, a state of charge (SOC), and a state of health (SOH) for each of a plurality of battery packs.

[0029] Figure 5 is an example view showing a battery device with a closed switch. DETAILED DESCRIPTION

[0030] Hereinafter, the embodiments disclosed in the specification are described in detail with reference to the accompanying drawings, and the same or similar components are represented by the same or similar reference numerals, and their overlapping descriptions are omitted. The terms "module" and / or "unit" of the components described in the following description are only used to make the specification easy to understand. Therefore, these terms themselves do not have meanings or functions that distinguish each other. In addition, when describing the embodiments of the present disclosure, a detailed description of the situation where the detailed description of the known technology related to the present disclosure may blur the main points of the present disclosure is omitted. In addition, it should be understood that the drawings are provided only to allow the embodiments of the present disclosure to be easy to understand, and the spirit of the present disclosure is not limited by the drawings, and includes all modifications, equivalents and substitutions included in the spirit and scope of the present disclosure.

[0031] Terms including ordinal numbers such as "first", "second", etc. may be used to describe various components. However, these components are not limited by these terms. These terms are only used to distinguish one component from another component.

[0032] It should be understood that the terms "including", "having", etc. used in the present application specify the existence of the features, numbers, steps, operations, components, parts or a combination thereof mentioned in the specification, and do not exclude the existence or possible addition of one or more other features, numbers, steps, operations, components, parts or a combination thereof.

[0033] A program implemented as an instruction set embodying a control algorithm necessary for controlling another configuration may be installed in a configuration for controlling another configuration under specific control conditions among the configurations according to one embodiment. The control configuration may process input data and stored data based on the installed program to thereby generate output data. The control configuration may include a non-volatile memory storing the program and a memory storing the data.

[0034] Figure 1 is a view showing a battery system according to one embodiment.

[0035] The battery system 1 may include a battery device 100 , a battery management system (BMS) 200 , relays 300 and 301 , and a plurality of switches SW1 to SW5 .

[0036] The battery apparatus 100 may include a plurality of battery packs 110 , 120 , 130 , 140 , and 150 connected in parallel to one another. Figure 1 It is shown that the number of the battery packs 110 , 120 , 130 , 140 , and 150 is five, the present disclosure is not limited thereto, and the battery system 1 may include three or more battery packs.

[0037] Each of the plurality of battery packs 110, 120, 130, 140, and 150 may include a plurality of battery cells. For example, the battery pack 110 may include a plurality of battery cells 111 to 114 connected in series to each other. Figure 1 While the number of the plurality of battery cells 111 to 114 is shown to be four, the present disclosure is not limited thereto, and each of the plurality of battery packs 110, 120, 130, 140 and 150 may be implemented as two or more battery cells connected in series with each other, a plurality of battery cells in which two or more battery cells are connected in parallel with each other are connected in series with each other, or two or more battery cells connected in parallel with each other.

[0038] One end of each of the relays 300 and 301 may be connected to the battery device 100, and the other end of each of the relays 300 and 301 may be connected to at least one component of the external device 2. Closing and opening of the relays 300 and 301 may be controlled based on relay control signals RCS1 and RCS2 supplied from the BMS 200.

[0039] The battery system 1 may be connected to an external device 2. The external device 2 may include a load or a charging device such as an inverter or a converter. When the external device 2 is a charger, both ends P+ and P- of the battery system 1 may be connected to the charger and supplied with power from the charger for charging. When the external device 2 is a load, both ends P+ and P- of the battery system 1 may be connected to the load, and the power supplied by the battery pack 10 may thus be discharged through the load.

[0040] The external device 2 may include a vehicle control unit (VCU) 21 included in the vehicle. The BMS 200 may communicate with the VCU 21 to exchange signals. The VCU 21 may receive a driving mode request for the vehicle from the BMS 200. The driving mode may include a plurality of vehicle modes, such as a driving mode in which the shifter is in the "D" gear, a stop mode in which the vehicle stops although the shifter is in the "D" gear, a parking mode in which the shifter is in the "P" gear, and an inspection mode in which the vehicle is inspected. When receiving the driving mode request, the VCU 21 may send a signal indicating one of the plurality of vehicle modes to the BMS 200 in response to the request.

[0041] When the driving mode is a driving mode indicated by a signal received by the BMS 200 from the VCU 21, the BMS 200 may determine which battery pack to perform the power operation among the plurality of battery packs 110, 120, 130, 140, and 150, and turn on the switch connected to the determined battery pack among the plurality of switches SW1 to SW5. The battery pack may then be connected to the node N1. The power operation may include a discharge operation of supplying power to the outside and a charging operation of power supplied from the outside. Here, at least one battery pack for performing the power operation may refer to two or more battery packs among the plurality of battery packs 110, 120, 130, 140, and 150, and in this case, the battery packs may be connected in parallel to each other.

[0042] Respective one ends of the plurality of switches SW1 to SW5 may be connected to each other at the node N1 , and the other end of each of the plurality of switches SW1 to SW5 may be connected in series to one end of each of the plurality of battery packs 110 , 120 , 130 , 140 , and 150 .

[0043] One end of the switch SW1 may be connected to the relay 300 at the node N1, and the other end of the switch SW1 may be connected to the positive terminal of the battery pack 110. One end of the switch SW2 may be connected to the relay 300 at the node N1, and the other end of the switch SW2 may be connected to the positive terminal of the battery pack 120. One end of the switch SW3 may be connected to the relay 300 at the node N1, and the other end of the switch SW3 may be connected to the positive terminal of the battery pack 130. One end of the switch SW4 may be connected to the relay 300 at the node N1, and the other end of the switch SW4 may be connected to the positive terminal of the battery pack 140. One end of the switch SW5 may be connected to the relay 300 at the node N1, and the other end of the switch SW5 may be connected to the positive terminal of the battery pack 150.

[0044] The BMS 200 may include a battery monitoring integrated circuit (BMIC) 210 and a main control unit (MCU) 220 .

[0045] The BMIC 210 may monitor a plurality of group voltages of the plurality of battery packs 110, 120, 130, 140, and 150. The BMIC 210 may receive a plurality of voltage measurement signals VS1 to VS5 from respective ends of the plurality of battery packs 110, 120, 130, 140, and 150. The BMIC 210 may include a plurality of terminals P1_1 to P1_5. Each of the plurality of terminals P1_1 to P1_5 may be connected to one end of each of the plurality of battery packs 110, 120, 130, 140, and 150 through each of the plurality of wirings LN1 to LN5. The BMIC 210 may receive a plurality of voltage measurement signals VS1 to VS5 through the plurality of terminals P1_1 to P1_5.

[0046] The positive terminal of the battery pack 110 may be connected to the terminal P1_1 through the wiring LN1, and the BMIC 210 may acquire the voltage measurement signal VS1 measured from the positive terminal of the battery pack 110 through the terminal P1_1. The positive terminal of the battery pack 120 may be connected to the terminal P1_2 through the wiring LN2, and the BMIC 210 may acquire the voltage measurement signal VS2 measured from the positive terminal of the battery pack 120 through the terminal P1_2. The positive terminal of the battery pack 130 may be connected to the terminal P1_3 through the wiring LN3, and the BMIC 210 may acquire the voltage measurement signal VS3 measured from the positive terminal of the battery pack 130 through the terminal P1_3. The positive terminal of the battery pack 140 may be connected to the terminal P1_4 through the wiring LN4, and the BMIC 210 may acquire the voltage measurement signal VS4 measured from the positive terminal of the battery pack 140 through the terminal P1_4. The positive terminal of the battery pack 150 may be connected to the terminal P1_5 through the wiring LN5 , and the BMIC 210 may acquire a voltage measurement signal VS5 measured from the positive terminal of the battery pack 150 through the terminal P1_5 .

[0047] The BMIC 210 may derive each group voltage of the plurality of battery groups 110, 120, 130, 140, and 150 from the plurality of voltage measurement signals VS1 to VS5. When receiving a request signal from the MCU 220, the BMIC 210 may acquire state information of the plurality of battery groups 110, 120, 130, 140, and 150 based on the request signal, and transmit a signal indicating the acquired state information to the MCU 220. The state information of the plurality of battery groups 110, 120, 130, 140, and 150 may include a group voltage, a group temperature, a group current, and the like of each battery group. For example, when receiving a request signal for requesting a battery group voltage or a battery group temperature from the MCU 220, the BMIC 210 may measure a group voltage or a group temperature of each of the plurality of battery groups 110, 120, 130, 140, and 150, and transmit a signal indicating the measured group voltage or group temperature to the MCU 220.

[0048] The battery device 100 may further include current sensors 101 to 105 corresponding to the plurality of battery packs 110, 120, 130, 140, and 150, respectively. The current sensors 101 to 105 may periodically measure the group current of each of the plurality of battery packs 110, 120, 130, 140, and 150, and provide signals (hereinafter referred to as "current measurement signals") CS1 to CS5 indicating the current measurement results to the MCU 220. The MCU 220 may receive the plurality of current measurement signals CS1 to CS5 from the plurality of current sensors 101 to 105, and estimate the state of charge (SOC) of each of the plurality of battery packs using the received current measurement signals CS1 to CS5. For example, when using the current integration result, the MCU 220 may estimate the SOC by integrating the values ​​indicated by the current measurement signals CS1 to CS5. In addition, the MCU 220 may use each of the current measurement signals CS1 to CS5 received from the current sensors 101 to 105 when calculating the amount of charge charged in or discharged from each battery pack in order to estimate the capacity of each of the plurality of battery packs.

[0049] Figure 1 It is shown that the multiple current sensors 101 to 105 directly provide current measurement signals to the MCU 220, and the present disclosure is not limited thereto. The multiple current sensors 101 to 105 can send the current measurement signals to the BMIC 210, and when a request signal for requesting the battery pack current is received from the MCU 220, the BMIC 210 can send information about the multiple current measurement signals obtained from the multiple current sensors to the MCU 220.

[0050] The MCU 220 can generate multiple candidate groups based on the group voltage of each battery group in the multiple battery groups 110, 120, 130, 140 and 150, determine a group that performs power operation among the multiple candidate groups based on the status information of the multiple battery groups 110, 120, 130, 140 and 150, and send a group control signal to the BMIC 210, which is used to turn on the switches among the multiple switches SW1 to SW5 connected to the battery group belonging to one of the determined groups.

[0051] The MCU 220 may generate a plurality of candidate groups including at least one battery pack among the plurality of battery packs 110, 120, 130, 140, and 150 based on the signal indicating the plurality of pack voltages received from the BMIC 210. The MCU 220 may estimate a state of charge (SOC) and a state of health (SOH) of each of the plurality of battery packs 110, 120, 130, 140, and 150, and estimate a capacity of each of the plurality of battery packs 110, 120, 130, 140, and 150 based on the estimated SOC and SOH. The MCU 220 may determine one group (hereinafter referred to as a "final connection group") that performs a power operation among the plurality of candidate groups based on the capacity of each of the at least one battery pack belonging to each of the plurality of candidate groups.

[0052] The SOC of a battery may indicate a remaining capacity charged in the battery and may be used as one of indicators representing the performance of the battery.

[0053] The MCU 220 may estimate the SOC in the unit of the battery cells included in each of the plurality of battery packs 110, 120, 130, 140, and 150, and estimate a representative value (e.g., an average value or a median value) of the SOC of the battery cells included in each of the plurality of battery packs 110, 120, 130, 140, and 150 as the SOC of the group. The MCU 220 may estimate the SOC in the unit of the cell by using a current integration method or a method using a relationship function or table between an open circuit voltage (OCV) and the SOC. Alternatively, the MCU 220 may estimate the SOC of the group based on each group current of the plurality of battery packs 110, 120, 130, 140, and 150 and values ​​of the cell voltage, cell temperature, etc. of the battery cells included in each of the plurality of battery packs 110, 120, 130, 140, and 150. Alternatively, the MCU 220 may estimate the SOC of the pack based on an equivalent circuit that models the electrical properties of the battery pack (i.e., a model equivalent circuit). The model equivalent circuit may include a resistance component and a capacitance component of a cell included in the battery pack, a wiring resistance that connects a plurality of cells to each other, etc. The method by which the MCU 220 estimates the SOC of each of the plurality of battery packs 110, 120, 130, 140, and 150 may be one of various known methods.

[0054] The SOH of a battery may indicate a degradation level or a remaining life of the battery and may be used as one of the indicators indicating the performance of the battery. The SOH may indicate the current capacity of each battery cell compared to the initial capacity of the battery cells included in the plurality of battery packs 110, 120, 130, 140, and 150. Here, the capacity may indicate the total amount of charge that may be contained in each cell.

[0055] The MCU 220 may estimate the SOH in units of battery cells included in each of the plurality of battery packs 110, 120, 130, 140, and 150, and estimate a representative value (e.g., an average value or a median value) of the SOH of the battery cells included in each of the plurality of battery packs 110, 120, 130, 140, and 150 as the SOH of the group. The MCU 220 may estimate the SOH in a unit of a cell by estimating the SOH of a cell based on the SOC of each of the battery cells, or by using a method of measuring the capacity of a corresponding cell based on the amount of charge required for charging or discharging the corresponding cell, etc. The method by which the MCU 220 estimates the SOH of each of the plurality of battery packs 110, 120, 130, 140, and 150 may be one of various known methods.

[0056] The MCU 220 may generate a group control signal for connecting at least one battery group belonging to the final connection group, and transmit it to the BMIC 210. Upon receiving the group control signal, the BMIC 210 may generate a plurality of switch control signals SS1 to SS5 based on the group control signal, and transmit it to the plurality of switches SW1 to SW5 to thereby control an opening or closing operation of the plurality of switches SW1 to SW5.

[0057] The plurality of switch control signals SS1 to SS5 may be signals for closing a switch corresponding to at least one battery pack belonging to the final connection group among the plurality of switches SW1 to SW5 and opening the remaining switches. For example, when the battery packs belonging to the final connection group are battery packs 140 and 150, the switch control signals SS4 and SS5 may be on-level signals, and the switch control signals SS1 to SS3 may be off-level signals.

[0058] The plurality of switches SW1 to SW5 may perform switching operations based on the plurality of switch control signals SS1 to SS5. The switches receiving the on-level switch control signals may be closed, and the switches receiving the off-level switch control signals may be opened. For example, the switches SW4 and SW5 receiving the on-level switch control signals SS4 and SS5, respectively, may be closed.

[0059] Figure 2 yes Figure 1 Detailed configuration view of the main control unit (MCU) shown in .

[0060] The MCU 220 may include a communication unit 221 , a connection group determination unit 222 , and a control unit 223 .

[0061] The communication unit 221 may communicate with the VCU 21 to transmit and receive information. The control unit 223 may control the communication unit 221 to transmit a driving mode request to the VCU 21. The communication unit 221 may transmit a signal received from the VCU 21 to the control unit 223. In this manner, the control unit 223 may transmit a driving mode request to the VCU 21 through the communication unit 221, and receive a signal indicating one of a plurality of vehicle modes from the VCU 21. The VCU 21 may generate a signal indicating a driving mode of the vehicle based on a random time point in a period from a time point when the driving mode request is received from the BMS 200 to a time point when the generated signal indicating one of a plurality of vehicle modes is transmitted to the BMS 200.

[0062] When receiving the signal indicating the driving mode, the control unit 223 may instruct the connection group determination unit 222 to determine the final connection group among the plurality of battery packs 110, 120, 130, 140, and 150. The connection group determination unit 222 may perform an operation (hereinafter referred to as a connection group determination operation) of determining the final connection group among the plurality of battery packs 110, 120, 130, 140, and 150 based on the instruction.

[0063] The control unit 223 may generate a group control signal for controlling closing of switches among the plurality of switches SW1 to SW5 connected to at least one battery group belonging to the final connection group determined by the connection group determination unit 222 , and transmit the group control signal to the BMIC 210 through the communication unit 221 .

[0064] In the following, the description refers to Figure 3 and Figure 4 A detailed operation of each of the communication unit 221 , the connection group determination unit 222 , and the control unit 223 is described.

[0065] Figure 3 is a flow chart of a parallel group control method according to another embodiment.

[0066] The communication unit 221 may receive a signal indicating that the vehicle is in the driving mode from the vehicle control unit (VCU) 21 (S1). The communication unit 221 may transmit the signal received from the VCU 21 to the control unit 223. When the signal indicating the driving mode is received in response to the driving mode request, the control unit 223 may instruct the connection group determination unit 222 to determine a final connection group among the plurality of battery packs 110, 120, 130, 140, and 150. The connection group determination unit 222 may perform a connection group determination operation based on the instruction.

[0067] The connection group determination unit 222 may determine an available group among the plurality of battery groups 110, 120, 130, 140, and 150 (S2). Here, the available group may be a battery group except a defective group among the plurality of battery groups 110, 120, 130, 140, and 150.

[0068] The defective group may refer to a group in which a failure occurs and a discharge operation and / or a charge operation is difficult among the plurality of battery groups 110 , 120 , 130 , 140 , and 150 .

[0069] The connection group determination unit 222 may derive a group voltage of each of the plurality of battery groups 110, 120, 130, 140, and 150 based on a signal received from each of the plurality of battery groups 110, 120, 130, 140, and 150, and derive a group temperature and / or a group current of each of the plurality of battery groups 110, 120, 130, 140, and 150 based on a signal received from a temperature sensor and / or a current sensor provided in each of the plurality of battery groups 110, 120, 130, 140, and 150. The connection group determination unit 222 may determine a battery group in which at least one of the group voltage, the group temperature, and the group current of each of the plurality of battery groups 110, 120, 130, 140, and 150 is outside a predetermined normal range as a defective group.

[0070] When the main control unit (MCU) 220 is activated, the connection group determination unit 222 may determine a problematic battery pack among the plurality of battery packs 110 , 120 , 130 , 140 , and 150 as a defective pack through a read only memory (ROM) diagnosis.

[0071] In the following, under the assumption Figure 1 A description is provided in the case where all of the plurality of battery packs 110 , 120 , 130 , 140 , and 150 are available packs.

[0072] The connection group determination unit 222 may group a plurality of candidate groups including battery groups having a group voltage as the reference group or less and a voltage deviation of a predetermined reference voltage or less by using each available battery group as a reference group ( S3 ).

[0073] This description refers to Figure 3The connection group determination unit 222 is described to group the plurality of candidate groups based on the available groups, and the present disclosure is not limited thereto. After step S1, the connection group determination unit 222 may group the plurality of candidate groups by using each of the plurality of battery groups 110, 120, 130, 140, and 150 as a reference group, the plurality of candidate groups including battery groups having a group voltage as the reference group or less and a voltage deviation of a predetermined reference voltage or less.

[0074] The BMIC 210 may transmit a signal indicating a plurality of group voltages to the MCU 220. The connection group determination unit 222 may generate a plurality of candidate groups based on the plurality of group voltages acquired according to the signal received from the battery monitoring integrated circuit (BMIC) 210. Figure 4 The operation of the connection group determination unit 222 is described by way of example.

[0075] Figure 4 is a table showing examples of a pack voltage, a state of charge (SOC), and a state of health (SOH) for each of a plurality of battery packs.

[0076] Figure 4 The "first group", "second group", "third group", "fourth group" and "fifth group" of Figure 1 The battery pack 110, the battery pack 120, the battery pack 130, the battery pack 140 and the battery pack 150.

[0077] refer to Figure 4 , the pack voltage of the battery pack 110 is 360 V, the pack voltage of the battery pack 120 is 360 V, the pack voltage of the battery pack 130 is 365 V, the pack voltage of the battery pack 140 is 380 V, and the pack voltage of the battery pack 150 is 390 V. Hereinafter, a description is provided assuming that 10 V is a predetermined reference voltage having a reference value of a voltage deviation.

[0078] The connection group determination unit 222 can sort the multiple battery groups 110, 120, 130, 140 and 150 in order of highest group voltage, set one of the multiple battery groups 110, 120, 130, 140 and 150 as a reference group based on the sorting order, and compare a predetermined reference voltage with a voltage deviation between the group voltage (i.e., the group voltage of a battery group among the multiple battery groups 110, 120, 130, 140 and 150 whose group voltage is the group voltage of the reference group or smaller) and the group voltage of the reference group.

[0079] Alternatively, the connection group determination unit 222 may sort the available battery groups among the plurality of battery groups 110, 120, 130, 140 and 150 in order of highest group voltage, set one of the available battery groups as a reference group based on the sorting order, and compare a predetermined reference voltage with a voltage deviation between the group voltage (i.e., the group voltage of a battery group among the available battery groups whose group voltage is the group voltage of the reference group or smaller) and the group voltage of the reference group.

[0080] The connection group determination unit 222 may sort the plurality of battery groups 110, 120, 130, 140, and 150 in order of the highest group voltage: battery group 150, battery group 140, battery group 130, battery group 120, and then battery group 110. The connection group determination unit 222 may derive a plurality of candidate groups by using each of the battery group 150, battery group 140, battery group 130, battery group 120, and battery group 110 as a reference group. A plurality of candidate groups may be derived using each of the plurality of battery groups 110, 120, 130, 140, and 150 as a reference group, and the maximum value of the number of candidate groups may therefore be the same as the number of battery groups.

[0081] The connection group determination unit 222 may use the battery pack 150 as a reference group and determine each of the battery packs 140 and 150 whose voltage deviation has a reference voltage of 10 V or less as a first group based on 390 V as the pack voltage of the battery pack 150 .

[0082] The connection group determination unit 222 may use the battery pack 140 as a reference group and determine the battery pack 140 whose voltage deviation has a reference voltage of 10 V or less as the second group based on 380 V as the group voltage of the battery pack 140 .

[0083] The connection group determination unit 222 may use the battery pack 130 as a reference group and determine each of the battery packs 110 , 120 , and 130 whose voltage deviation has a reference voltage of 10V or less as a third group based on 365V as the pack voltage of the battery pack 130 .

[0084] The connection group determination unit 222 may use the battery pack 120 as a reference group and determine the battery packs 110 and 120 whose voltage deviation has a reference voltage of 10 V or less as the fourth group based on 360 V as the pack voltage of the battery pack 120 .

[0085] When the group generated based on each reference group overlaps with another group, the connection group determination unit 222 may use one of the overlapping groups as a candidate group. When the connection group determination unit 222 uses the battery pack 110 as the reference group, the fifth group may overlap with the fourth group, and the fifth group includes each of the battery packs 110 and 120 whose voltage deviation has a reference voltage of 10V or less based on 360V as the pack voltage of the battery pack 110. Therefore, the connection group determination unit 222 may determine the first to fourth groups except the fifth group as candidate groups.

[0086] The connection group determination unit 222 may estimate the capacity of each of the plurality of battery packs 110, 120, 130, 140, and 150 (S4). The connection group determination unit 222 may estimate the state of charge (SOC) and the state of health (SOH) of each of the plurality of battery packs 110, 120, 130, 140, and 150, and estimate the capacity of each of the plurality of battery packs 110, 120, 130, 140, and 150 based on the initial capacity, SOC value, and SOH value of the battery pack.

[0087] The connection group determination unit 222 may estimate the SOC of each of the plurality of battery packs 110, 120, 130, 140, and 150. Figure 4 , the connection group determination unit 222 may estimate the respective SOCs of the battery groups 110 , 120 , 130 , 140 , and 150 as 70%, 70%, 75%, 85%, and 90%.

[0088] The connection group determination unit 222 may estimate the SOH of the battery pack of each of the plurality of battery packs 110, 120, 130, 140, and 150. Figure 4 , the connection group determination unit 222 may estimate the respective SOHs of the battery groups 110 , 120 , 130 , 140 , and 150 as 80%, 70%, 70%, 95%, and 95%.

[0089] The connection group determination unit 222 may estimate the initial capacity of each of the plurality of battery packs 110, 120, 130, 140, and 150 based on the initial capacity of each of the battery cells included in each of the plurality of battery packs 110, 120, 130, 140, and 150. Hereinafter, for ease of explanation, it is assumed that 50 Ah is the initial capacity of each of the plurality of battery packs 110, 120, 130, 140, and 150.

[0090] The connection group determination unit 222 may estimate the capacity of each of the plurality of battery packs 110, 120, 130, 140, and 150 based on the initial capacity, SOC value, and SOH value of each of the plurality of battery packs 110, 120, 130, 140, and 150. The connection group determination unit 222 may estimate the capacity of each of the plurality of battery packs 110, 120, 130, 140, and 150 by multiplying the initial capacity, SOC value, and SOH value of each of the plurality of battery packs 110, 120, 130, 140, and 150.

[0091] refer to Figure 4 , the capacity of battery pack 110 may be 50 Ah*0.7*0.8=28 Ah, the capacity of battery pack 120 may be 50 Ah*0.7*0.7=24.5 Ah, the capacity of battery pack 130 may be 50 Ah*0.75*0.7=26.2 Ah, the capacity of battery pack 140 may be 50 Ah*0.85*0.95=40.3 Ah, and the capacity of battery pack 150 may be 50 Ah*0.9*0.95=42.7 Ah.

[0092] The connection group determination unit 222 may determine a final connection group among the plurality of candidate groups based on the capacity of each of the plurality of battery packs 110, 120, 130, 140, and 150 (S5). The connection group determination unit 222 may obtain a total capacity of at least one battery pack belonging to each of the plurality of candidate groups, and determine a candidate group having a maximum value of the total capacity as the final connection group.

[0093] refer to Figure 4 , the total capacity of the first group including battery pack 140 and battery pack 150 may be 40.3 Ah+42.7 Ah=83.0 Ah. The total capacity of the second group including battery pack 140 may be 40.3 Ah. The total capacity of the third group including battery pack 110, battery pack 120, and battery pack 130 may be 28 Ah+24.5 Ah+26.2 Ah=78.7 Ah. The total capacity of the fourth group including battery pack 110 and battery pack 120 may be 28 Ah+24.5 Ah=52.5 Ah.

[0094] The connection group determination unit 222 may determine the first group having the maximum value (i.e., 83.0 Ah) among the total capacity of the plurality of battery packs 110, 120, 130, 140, and 150 as the final connection group. Therefore, the battery packs connected to the node N1 among the plurality of battery packs 110, 120, 130, 140, and 150 may be the battery packs 140 and 150 belonging to the first group.

[0095] When the connection group determination unit 222 determines the final connection group, the control unit 223 may generate a group control signal that causes at least one battery group belonging to the final connection group to perform a power operation. Figure 4 The battery pack control signal may include a signal that enables the battery packs 140 and 150 to perform power operations. The communication unit 221 may transmit the battery pack control signal to the BMIC 210, and the battery management system (BMS) 200 may control switches corresponding to the battery packs belonging to the final connection group through the BMIC 210 (S6).

[0096] The BMIC 210 may control the switching operation of the plurality of switches SW1 to SW5 based on the group control signal. When receiving the group control signal, the BMIC 210 may generate a plurality of switch control signals SS1 to SS5 for closing the switch corresponding to at least one battery pack belonging to the final connection group among the plurality of switches SW1 to SW5 and opening the remaining switches. For example, the BMIC 210 may set each of the switch control signals SS4 and SS5 to have an on level, and set each of the switch control signals SS1 to SS3 to have an off level, and the switch control signals SS4 and SS5 correspond to the battery pack 140 and the battery pack 150, respectively, which are the battery packs belonging to the final connection group. The BMIC 210 may send the plurality of switch control signals SS1 to SS5 to the plurality of switches SW1 to SW5.

[0097] Among the plurality of switches SW1 to SW5, switches receiving on-level control signals may be closed, and switches receiving off-level switch control signals may be opened. For example, switches SW4 and SW5 receiving on-level switch control signals SS4 and SS5 may be closed, and switches SW1, SW2, and SW3 receiving off-level switch control signals SS1-SS3 may be opened.

[0098] Figure 5 is an example view showing a battery device with a closed switch.

[0099] refer to Figure 5 , in the Figure 1 Among the plurality of battery packs 110, 120, 130, 140, and 150 of the battery device 100, switches SW4 and SW5 may be closed, and switches SW1, SW2, and SW3 may be opened. Battery pack 140 and battery pack 150 among the plurality of battery packs 110, 120, 130, 140, and 150 may perform power operations based on switch operations of the plurality of switches SW1 to SW5.

[0100] In one embodiment, the capacity of the plurality of battery packs 110, 120, 130, 140, and 150 may be estimated considering not only the SOC of the battery pack but also the SOH of the battery pack, and the battery pack to be connected in parallel with the battery system 1 may be determined based on the estimated capacity. The capacity of the battery pack determined considering the SOC and SOH of the battery pack may allow the actual amount of energy of the battery pack to be estimated. Therefore, among the plurality of battery packs 110, 120, 130, 140, and 150, the battery device 100 in which the group combination is connected in parallel with each other may have the best performance considering the actual amount of energy.

[0101] Although the embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto. Various modifications and improvements made by technicians in the field to which the present disclosure belongs also belong to the scope of the present disclosure.

Claims

1. A battery system comprising: a plurality of battery packs connected in parallel with each other; a plurality of switches, for each of the plurality of battery packs, the plurality of switches being connected in series to one of the two ends of each battery pack; a battery monitoring integrated circuit (BMIC) that acquires status information of a plurality of group voltages including the plurality of battery groups; as well as A main control unit (MCU) is configured to generate a plurality of candidate groups including at least one battery group among the plurality of battery groups based on the plurality of group voltages, estimate a capacity of each of the plurality of battery groups based on the status information, determine a final connection group for performing power operations among the plurality of candidate groups based on the capacity of each of the plurality of battery groups, and send a group control signal to the BMIC for turning on a switch among the plurality of switches connected to a battery group belonging to the final connection group.

2. The system according to claim 1, wherein: The MCU sorts the multiple battery groups in order of highest group voltage, and based on the sorting order, by using each of the multiple battery groups as a reference group, determines a group including battery groups among the multiple battery groups that have a group voltage as the reference group or smaller and whose voltage deviation from the group voltage of the reference group is a predetermined reference voltage or smaller as the candidate group.

3. The system according to claim 2, wherein: The MCU estimates, for each of the plurality of battery packs, a state of charge (SOC) and a state of health (SOH) of the battery pack, and estimates, for each of the plurality of battery packs, a capacity of each of the plurality of battery packs based on the SOC and the SOH of the battery pack.

4. The system of claim 3, wherein: The MCU derives a capacity as a total capacity of at least one battery pack belonging to each of the plurality of candidate groups based on a capacity of each of the plurality of battery packs.

5. The system according to claim 4, wherein: The MCU determines the one final connection group among the plurality of candidate groups based on the total capacity.

6. The system according to claim 5, wherein: When receiving the group control signal from the MCU, the BMIC sends a signal to the multiple switches by generating a switch control signal, wherein the switch control signal is used to close a first switch among the multiple switches connected to at least one battery group belonging to the final connection group and to open the remaining switches among the multiple switches except the first switch.

7. The system according to claim 1, wherein: The MCU determines available battery groups among the multiple battery groups, sorts the available battery groups in order of highest group voltage, and based on the sorting order, by using each of the available battery groups as a reference group, determines a group including battery groups among the multiple available battery groups that have a group voltage as the reference group or less and have a voltage deviation from the group voltage of the reference group of a predetermined reference voltage or less as the candidate group.

8. A parallel group control method, comprising: A signal is received by a battery management system (BMS) from a vehicle control unit (VCU) indicating that the vehicle is in a driving mode; grouping, by the BMS, a plurality of candidate groups based on a group voltage of each battery group in a plurality of battery groups connected in parallel with each other, each candidate group including at least one battery group among the plurality of battery groups; estimating, by the BMS, a state of charge (SOC) and a state of health (SOH) of each of the plurality of battery packs, and estimating, by the BMS, a capacity of each of the plurality of battery packs based on the SOC and SOH of the battery pack for each of the plurality of battery packs; as well as A final connection group is determined by the BMS among the plurality of candidate groups based on a capacity of each of the plurality of battery packs.

9. The method according to claim 8, wherein: The grouping of the plurality of candidate groups comprises: sorting the plurality of battery groups in order of highest group voltage; and Based on the sorting order, by using each of the multiple battery groups as a reference group, a group including battery groups among the multiple battery groups that have a group voltage as the reference group or smaller and whose voltage deviation from the group voltage of the reference group is a predetermined reference voltage or smaller is determined as the candidate group.

10. The method according to claim 9, wherein: Determining the one final connection group among the plurality of candidate groups comprises: deriving a capacity as a total capacity of at least one battery pack belonging to each of the plurality of candidate groups based on the capacity of each of the plurality of battery packs, and The one final connection group is determined among the plurality of candidate groups based on the total capacity.

11. The method according to claim 9, further comprising: A switch control signal is generated by the BMS, the switch control signal being used to close a first switch connected to the battery pack belonging to the final connection group among a plurality of switches connected in series to one of the two ends of each battery pack, and to open the remaining switches except the first switch among the plurality of switches for each of the plurality of battery packs, and the switch control signal is sent by the BMS to the plurality of switches.

12. The method according to claim 9, wherein: The grouping of the plurality of candidate groups comprises: determining an available battery pack among the plurality of battery packs, The available battery groups are sorted in order of highest group voltage, and based on the sorting order, by using each of the available battery groups as a reference group, a group including battery groups among the multiple available battery groups that have a group voltage as the reference group or less and whose voltage deviation from the group voltage of the reference group is a predetermined reference voltage or less is determined as the candidate group.

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