Battery control device, battery system, power supply system, and battery control method

Abstract

A battery control apparatus according to the present application includes a plurality of switching circuits connected in series one-to-one to a plurality of battery packs, a plurality of sensing circuits connected one-to-one to the plurality of battery packs and generating sensing signals indicating a voltage and a current of each battery pack, and a control circuit for determining a voltage, a state of health (SOH), and a state of charge (SOC) of each of the plurality of battery packs based on the sensing signals, wherein the control circuit is configured to set all of the plurality of battery packs as discharge candidates if there is no battery pack having an SOH greater than a reference SOH from among a difference between a maximum SOH of the plurality of battery packs, apply a grouping rule to the discharge candidates to set at least one first group including at least one battery pack, set the first group as a discharge group if the first group is one, turn on each switching circuit corresponding to each battery pack included in the discharge group, and turn off the switching circuit corresponding to each of the remaining battery packs other than the discharge group.

Description

Technical Field

[0001] This application claims the benefit of Korean Patent Application No. 10-2021-0003201, filed with the Korean Intellectual Property Office on January 11, 2021, the disclosure of which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to techniques for reducing state of health (SOH) differences between multiple battery packs. Background Technology

[0003] Recently, the demand for portable electronic products such as laptops, cameras and mobile phones has increased rapidly, and with the widespread development of electric vehicles, batteries for energy storage, robots and satellites, there is a lot of research being conducted on high-performance batteries that can be recharged repeatedly.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among them, lithium batteries have almost no or no memory effect, and therefore receive more attention than nickel-based batteries. This is because lithium batteries have the advantages of being able to be charged at any convenient time, having a very low self-discharge rate, and high energy density.

[0005] Recently, not only energy storage systems but also electric vehicles require high capacity for stable power management. Therefore, battery banks that are installed with multiple batteries connected in parallel are typically used for control, allowing at least one of the batteries to be selectively connected in parallel according to the power requirements of external devices.

[0006] When performing a battery pack discharge event, conventional techniques control all or some of the batteries in multiple cells to participate in the discharge event in descending order of state of charge (SOC) for continuous and stable discharge.

[0007] This method is effective to some extent when performing a small number of discharge events. However, when only the State of Charge (SOC) is used as the most important parameter for discharge control without considering the State of Health (SOH) of each cell, this eventually leads to uneven degradation of multiple cells. In particular, in the long run, the overall operating efficiency of the system is reduced due to some cells with significantly lower SOH, and the repair, replacement, and restoration of the corresponding cells are costly and time-consuming. Summary of the Invention

[0008] Technical issues

[0009] This disclosure is designed to address the aforementioned problems, and therefore aims to provide a battery control device, battery system, power supply system, and battery control method for reducing state of health (SOH) differences among multiple batteries in selective parallel control of at least one of multiple batteries.

[0010] These objects and advantages of this disclosure, as well as other objects and advantages, will be understood from the following description and will be apparent from implementation of this disclosure. Furthermore, it will be readily understood that the objects and advantages of this disclosure can be achieved through the methods and combinations thereof set forth in the appended claims.

[0011] Technical solution

[0012] A battery control device according to one aspect of this disclosure includes: a plurality of switching circuits connected in series with a plurality of battery packs in a one-to-one relationship; a plurality of sensing circuits connected in a one-to-one relationship with the plurality of battery packs and configured to generate sensing signals indicating the voltage and current of each battery pack; and a control circuit configured to determine the voltage, state of health (SOH), and state of charge (SOC) of each of the plurality of battery packs based on the sensing signals. When no battery pack has a SOH with a difference greater than a reference SOH between the maximum SOH of the plurality of battery packs, the control circuit is configured to set all the plurality of battery packs as discharge candidates. The control circuit is configured to set at least one first group, each comprising at least one battery pack, by applying a grouping rule to all discharge candidates. In the case of a single first group, the control circuit is configured to set the first group as a discharge group. The control circuit is configured to turn on each switching circuit corresponding to each battery pack in the discharge group and turn off the switching circuit corresponding to each remaining battery pack other than the discharge group.

[0013] When there is a battery pack with a SOH that has a difference between the maximum SOH of the multiple battery packs and a reference SOH greater than the reference SOH, the control circuit is configured to set the remaining battery packs in the multiple battery packs as discharge candidates, excluding the battery packs with a SOH that is lower than the maximum SOH but equal to or greater than the reference SOH.

[0014] The grouping rules stipulate that each first group includes the maximum number of battery packs in which the voltage difference between the maximum and minimum voltages is equal to or less than the reference voltage.

[0015] In the case of multiple first groups, the control circuit can be configured to determine the sum of the State of Charge (SOC) of each of the multiple first groups. The sum of the SOC is the sum of the SOCs of all battery packs in each first group. The control circuit can be configured to designate each of the multiple first groups with the largest sum of SOC as a second group. In the case of a single second group, the control circuit can be configured to designate the second group as a discharge group.

[0016] In the case of multiple second groups, the control circuit can be configured to designate each of the multiple second groups with the largest number of members as a third group. In the case of a single third group, the control circuit can be configured to designate the third group as a discharge group.

[0017] In the case of multiple third groups, the control circuit can be configured to determine the discharge risk factor of each of the multiple third groups. The control circuit can be configured to set the third group with the lowest discharge risk factor as the discharge group.

[0018] In the case of multiple third groups, the control circuit can be configured to determine the discharge priority factor of each of the multiple third groups. The control circuit can be configured to set the third group with the highest discharge priority factor as the discharge group.

[0019] Another aspect of the battery system according to this disclosure includes a battery control device.

[0020] According to another aspect of this disclosure, the power supply system includes a battery system.

[0021] A battery control method according to another aspect of this disclosure can be executed by a battery control device. The battery control method includes: determining the voltage, state of equilibrium (SOH), and state of charge (SOC) of each of the plurality of battery packs based on sensing signals indicating the voltage and current of each of the plurality of battery packs; setting all the plurality of battery packs as discharge candidates when there is no battery pack having an SOH with a difference greater than a reference SOH between the maximum SOH of the plurality of battery packs and the SOH of the battery packs; setting at least one first group, each comprising at least one battery pack, by applying grouping rules to all discharge candidates; setting the first group as a discharge group in the case of a single first group; and turning on each switching circuit corresponding to each battery pack in the discharge group and turning off each switching circuit corresponding to the remaining battery packs other than the first group.

[0022] When there is any battery pack with a state of OH that has a difference between the maximum state of OH and the reference state of OH greater than that of the reference state of OH, the battery control method may further include setting the remaining battery packs among the multiple battery packs as discharge candidates, excluding the battery packs with a state of OH that is lower than the maximum state of OH but equal to or greater than the reference state of OH.

[0023] Beneficial effects

[0024] According to at least one embodiment of the embodiments of this disclosure, the state of health (SOH) difference among multiple batteries can be reduced in the selective parallel control of at least one of multiple batteries.

[0025] The effects of this disclosure are not limited to those mentioned above, and those skilled in the art will clearly understand these and other effects from the appended claims. Attached Figure Description

[0026] The accompanying drawings illustrate preferred embodiments of the present disclosure and are used together with the detailed description of the present disclosure described below to provide a further understanding of the technical aspects of the present disclosure; therefore, the present disclosure should not be construed as limited to the drawings.

[0027] Figure 1 This is an example diagram of a power supply system based on the contents of this disclosure.

[0028] Figure 2 It is shown in the description from Figure 1 The example shown is a data table used as a reference during the process of determining the discharge group for multiple battery packs.

[0029] Figure 3 It is shown in the description from Figure 1 This is another example of a data table used as a reference during the process of determining the discharge group for multiple battery packs.

[0030] Figure 4 and Figure 5 This is an exemplary flowchart of a battery control method according to an embodiment of the present disclosure. Detailed Implementation

[0031] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms or words used in the specification and appended claims should not be construed as limited to their general and dictionary meanings, but rather as having meanings and concepts corresponding to the technical aspects of the present disclosure, and as per the principle of allowing the inventors to appropriately define terms to obtain the best interpretation.

[0032] Therefore, the embodiments described herein and the descriptions in the accompanying drawings are only the most preferred embodiments of this disclosure, but are not intended to fully describe the technical aspects of this disclosure. It should be understood that various other equivalents and modifications may have been made thereto at the time of filing the application.

[0033] Terms including serial numbers such as "first" and "second" are used to distinguish one element from other elements among various elements, but are not intended to limit the elements.

[0034] Unless the context clearly indicates otherwise, it should be understood that, as used herein, the term "comprising" specifies the presence of the stated element but does not exclude the presence or addition of one or more other elements. Additionally, as used herein, the term "control unit" refers to a processing unit having at least one function or operation and can be implemented by hardware and software, alone or in combination.

[0035] Furthermore, as will be further understood throughout the specification, when an element is referred to as being “connected to” other elements, it can be directly connected to those other elements, or there may be intermediate elements present.

[0036] Figure 1 This is an example diagram of a power supply system 1 based on the present disclosure.

[0037] Reference Figure 1 The power supply system 1 includes a power conversion system 10 and a battery system 100.

[0038] The power conversion system 10 is electrically connected between the battery system 100 and the power grid 2 and / or the electrical load 3. The power conversion system 10 uses a DC-AC inverter and / or DC-DC converter provided herein to handle bidirectional power transfer between the battery system 100 and the power grid 2 and / or the electrical load 3. Specifically, in charging mode, the power conversion system 10 can convert AC power supplied from the power grid 2 into DC power and supply the DC power to the battery system 100. Conversely, in discharging mode, the power conversion system 10 can convert DC power input through the battery system 100 into AC power and supply the AC power to the power grid 2 and / or the electrical load 3.

[0039] The power conversion system 10 can acquire status information of the battery system 100 and each element in the power grid, and transmit charging commands, discharging commands, and / or rest commands to the battery system 100 based on the acquired status information. While transmitting charging commands, the power conversion system 10 controls the DC-AC inverter to charging mode. While transmitting discharging commands, the power conversion system 10 controls the DC-AC inverter to discharging mode.

[0040] A charging command is a signal that instructs the battery system 100 to store DC power supplied from the power conversion system 10. A discharging command is a signal that instructs the battery system 100 to supply the stored DC power to the power conversion system 10. A rest command is a signal that instructs the battery system 100 to stop charging and discharging.

[0041] The battery system 100 includes a battery compartment BB and a battery control device 120.

[0042] Battery BB comprises multiple battery packs BP_1 to BP_6. In the instruction manual, the symbol "BP" is used to denote each battery pack in a common description of the multiple battery packs BP_1 to BP_6. Although Figure 1 A battery library BB comprising a total of six battery packs BP_1 to BP_6 is shown for ease of description, wherein the battery library BB includes at least two battery packs BP, but there is no particular limitation on the number of battery packs BP.

[0043] The battery pack BP includes at least one battery cell BC connected in series. In this specification, the battery cell BC refers to a basic unit of a battery that can be charged individually, and the battery cell BC is not limited to a specific type and may include any type of rechargeable battery, such as a lithium-ion cell BC.

[0044] The battery control device 120 is configured to control discharge and / or charging events of multiple battery packs BP_1 to BP_6 to reduce the difference in degradation level among the multiple battery packs BP_1 to BP_6.

[0045] The battery control device 120 includes multiple switching circuits 200_1 to 200_6, multiple sensing circuits 300_1 to 300_6, and a control circuit 400.

[0046] Multiple switching circuits 200_1 to 200_6 are connected in series with multiple battery packs BP_1 to BP_6 in a one-to-one relationship. That is, the multiple battery packs BP_1 to BP_6 are connected in parallel through multiple switching circuits 200_1 to 200_6. In the specification, in the general description of the multiple switching circuits 200_1 to 200_6, the reference numeral "200" is assigned to the switching circuit. The switching circuit 200 is not limited to a particular type and can include any type of switching circuit capable of switching on / off the current path between the battery pack BP and the power conversion system 10. For example, the switching circuit 200 may include semiconductor switches such as metal-oxide-semiconductor field-effect transistors (MOSFETs) and mechanical switches such as relays. In another example, the switching circuit 200 may include a bidirectional DC-DC converter. When i is a natural number, when the switching circuit 200_i is turned on, the battery pack BP_i can be charged / discharged. When the switching circuit 200_i is turned off, the battery pack BP_i is electrically disconnected from the power conversion system 10.

[0047] Multiple sensing circuits 300_1 to 300_6 are connected in a one-to-one relationship to multiple battery packs BP_1 to BP_6. Sensing circuit 300 includes a voltage sensor 310 and a current sensor 320. In the general description of the multiple sensing circuits 300_1 to 300_6 in the specification, the reference numeral "300" is assigned to the sensing circuit. Sensing circuit 300 uses voltage sensor 310 and current sensor 320 to measure the voltage and current of the connected battery pack BP. Voltage sensor 310 is connected in parallel to battery pack BP and measures the voltage across battery pack BP. Current sensor 320 is connected to the power line connecting battery pack BP to switching circuit 200 and measures the current flowing through battery pack BP. Sensing circuit 300 generates sensing signals indicating the measured voltage and measured current. The sensing signals indicate a pair of synchronously detected voltage and current values.

[0048] The control circuit 400 may be implemented in hardware using at least one of an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field-programmable gate array (FPGA), a microprocessor, or an electronic unit for performing other functions.

[0049] The control circuit 400 may include a memory device. The memory device may include at least one type of storage medium selected from flash memory, hard disk, solid-state drive (SSD), silicon disk drive (SDD), multimedia card micro, random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), or programmable read-only memory (PROM). The memory device may store data and programs required for calculations by the control circuit 400. The memory device may also store data indicating the results of calculations by the control circuit 400.

[0050] The control circuit 400 is operatively coupled to a plurality of switching circuits 200_1 to 200_6, a plurality of sensing circuits 300_1 to 300_6, and a power conversion system 10. Operable coupling means a unidirectional or bidirectional connection for transmitting and receiving signals.

[0051] The control circuit 400 periodically or irregularly collects sensing signals from each of the plurality of sensing circuits 300_1 to 300_6. Based on the sensing signals, the control circuit 400 determines the voltage, state of health (SOH), and state of charge (SOC) of each of the plurality of battery packs BP_1 to BP_6.

[0052] State of Charge (SOH) is the ratio of maximum capacity to design capacity, and SOC is typically expressed as a range between 0% and 100%. Design capacity indicates the maximum amount of charge that can be stored in the battery pack (BP) when it is in a brand-new condition. Maximum capacity indicates the maximum amount of charge that can be stored in the battery pack (BP) as it deteriorates from a brand-new condition. As the battery pack (BP) deteriorates, the maximum capacity gradually decreases from the design capacity.

[0053] State of Charge (SOC) is the ratio of remaining capacity to maximum capacity, and is typically expressed as a range between 0% and 100%. Remaining capacity indicates the amount of charge currently stored in the battery pack (BP).

[0054] Each of SOH and SOC can be estimated based on at least one of a variety of known schemes, and their detailed descriptions are omitted.

[0055] When the control circuit 400 receives a discharge command from the power conversion system 10, the control circuit 400 executes a discharge event in response to the discharge command. The discharge event is the process of selecting at least one of a plurality of battery packs BP_1 to BP_6 and turning on the switching circuit 200 corresponding to each selected battery pack BP to supply DC power from each selected battery pack BP to the power conversion system 10.

[0056] A discharge event begins when at least one of the multiple battery packs BP_1 to BP_6 is set as a discharge candidate via control circuit 400. The setting of the discharge candidate will be described in detail below.

[0057] First, the control circuit 400 determines the maximum SOH by comparing the SOH of each of the multiple battery packs BP_1 to BP_6. Then, the control circuit 400 determines whether there is any SOH whose difference from the maximum SOH is greater than a reference SOH. For example, the control circuit 400 determines whether the difference between the maximum SOH and the minimum SOH is equal to or greater than the reference SOH. The reference SOH is a preset value (e.g., 3%) for reducing the frequency of use in charging and / or discharging events of any of the multiple battery packs BP_1 to BP_6 with a smaller SOH, thereby reducing the SOH difference between the multiple battery packs BP_1 to BP_6.

[0058] When no battery pack has a state of equilibrium (SOH) less than the maximum SOH but equal to or greater than the reference SOH, the control circuit 400 sets all battery packs BP_1 to BP_6 as discharge candidates. Conversely, when a battery pack has a state of equilibrium (SOH) less than the maximum SOH but equal to or greater than the reference SOH, the control circuit 400 sets the remaining battery packs BP, excluding those with a state of equilibrium (SOH less than the maximum SOH but equal to or greater than the reference SOH), as discharge candidates. When only one battery pack BP is set as a discharge candidate, the corresponding discharge event for that battery pack BP can be executed immediately.

[0059] The control circuit 400 selects at least one battery pack BP from the discharge candidates using a preset grouping rule, and will actually execute the discharge event of that at least one battery pack BP. The grouping rule is to prevent inrush currents that may occur when at least two battery packs BP with a voltage difference equal to or greater than the reference voltage are connected in parallel simultaneously.

[0060] Grouping rules are used to set at least one first group from the discharge candidates, and to group the battery packs BP whose voltage difference between the maximum and minimum voltages is equal to or less than a reference voltage (e.g., 10 V) into the same group. In the specification, each group set according to the grouping rules is referred to as a first group. Control circuit 400 extracts all first groups from the discharge candidates that satisfy the grouping rules. When at least two first groups are set according to the grouping rules, a particular battery pack (e.g., BP_3) can be a common member of at least two different first groups.

[0061] In the following text, reference will be made to Figure 2 and Figure 3 The description defines the operation of identifying a discharge group that includes at least one of multiple battery packs BP_1 to BP_6 as its members.

[0062] Figure 2 Table A (TABLE_A) shows the voltage, SOC, and SOH of each of the multiple battery packs BP_1 to BP_6. For ease of description, Figure 2 Table TABLE_A shows the voltages of the first to sixth battery packs (BP_1 to BP_6) arranged in descending order. Figure 2 In this case, when the reference SOH is 3%, all battery packs BP_1 to BP_6 are set as discharge candidates because the 2% difference between the maximum SOH of 90% and the minimum SOH of 88% is less than the reference SOH.

[0063] The control circuit 400 determines at least one first group from the discharge candidates BP_1 to BP_6 by applying a grouping rule to the discharge candidates BP_1 to BP_6. When only one first group is determined, the control circuit 400 turns on each switch circuit 200 corresponding to each battery pack BP in the corresponding first group, and turns off each switch circuit 200 corresponding to the remaining battery packs BP other than the first group.

[0064] according to Figure 2 Table TABLE_A uses 10V as the reference voltage to determine a total of three first groups according to the grouping rules. That is, the first battery group BP_1 and the second battery group BP_2 are determined to be the first group G#1_1, the second battery group BP_2 and the third battery group BP_3 are determined to be another first group G#1_2, and the fourth battery group BP_4, the fifth battery group BP_5 and the sixth battery group BP_6 are determined to be another first group G#1_3.

[0065] For reference, according to the grouping rules, when there is any other discharge candidate whose voltage difference between each discharge candidate and the reference voltage is less than the reference voltage, it cannot be set as a single member of the first group. For example, since the 3V voltage difference between the third battery group BP_3 and the second battery group BP_2 is less than the reference voltage of 10V, the third battery group BP_3 and the second battery group BP_2 cannot be single members of the first group.

[0066] like Figure 2 As shown, in the case of multiple first groups G#1_1 to G#1_3, the control circuit 400 sets the first group with the largest sum of SOC as the second group. The sum of SOC is the sum of the SOC of each battery pack BP in each first group. According to... Figure 2 In table TABLE_A, the sum of the SOCs of the first group G#1_1 is 61%, the sum of the SOCs of the other first group G#1_2 is 64%, and the sum of the SOCs of the other first group G#1_3 is 64%. Since the two first groups G#1_2 and G#1_3 have the largest sum of SOCs, the two first groups G#1_2 and G#1_3 out of the three first groups G#1_1 to G#1_3 are respectively set as the second groups G#2_1 and G#2_2.

[0067] When only one second group is determined, the control circuit 400 turns on the switch circuit 200 corresponding to each battery pack BP of the corresponding second group, and turns off the switch circuit 200 corresponding to the remaining battery pack BP other than the second group.

[0068] Conversely, when Figure 2When at least two second groups G#2_1 and G#2_2 are set as shown, the control circuit 400 sets any one of the at least two second groups G#2_1 and G#2_2 with the largest number of members as the third group. Since the second group G#2_1 has 2 members and the other second group G#2_2 has 3 members, the other second group G#2_2 is set as the third group G#3.

[0069] like Figure 2 As shown, when only one third group G#3 is determined, the control circuit 400 sets the third group G#3 as a discharge group. The control circuit 400 turns on the switch circuits 200_4 to 200_6 corresponding to the battery groups BP_4 to BP_6 that are members of the discharge group G#3, and turns off the switch circuits 200_1 to 200_3 corresponding to the remaining battery groups BP_1 to BP_3 other than the discharge group G#3.

[0070] and Figure 2 Conversely, when at least two third groups are determined, the control circuit 400 can determine the discharge risk factor of each third group and set any one of the at least two third groups with the minimum discharge risk factor as the fourth group.

[0071] The discharge risk factor for a specific group corresponds to the amount of damage inflicted on the battery pack belonging to the corresponding specific group by additional discharge from the current time. Regarding the discharge risk factor, battery pack BP has the following characteristic: the closer the State of Charge (SOC) is to a fully discharged state below a reference SOC (i.e., SOC 0%), the faster the degradation. The reference SOC is preset by testing a test battery pack with the same electrochemical specifications as battery pack BP. That is, even if the discharge capacity is equal, the degradation rate of battery pack BP will differ depending on the SOC of battery pack BP. Given this fact, control circuit 400 can determine the discharge risk factor for each third group using the following Equation 1.

[0072] Equation 1

[0073]

[0074] In equation 1, P A y is the discharge risk factor for a specific group, and y is the number of members in the specific group. m is a predetermined index greater than 1 (e.g., 2), and n is a predetermined index greater than 1 (e.g., 1.3). The first and second indices are preset by testing the test battery pack in the same manner as with the reference SOC. r It is a reference to SOC and SOC x When the SOC is the xth member of a specific group, in the SOC x Equal to or greater than SOCr In the case of SOC, ΔSOC1[x] is set to 0, and when SOC x Less than SOC r When ΔSOC1[x] is set to equal (SOC... x -SOC r When SOC x Equal to or greater than SOC r When ΔSOC2[x] is set to equal (SOC... x -SOC r ), and when SOC x Less than SOC r At that time, ΔSOC2[x] is set to 0.

[0075] Alternatively, when at least two third groups are determined, the control circuit 400 can determine the discharge priority factor of each third group and set any one of the at least two third groups with the largest discharge priority factor as the fourth group.

[0076] The discharge priority factor of a specific group corresponds to the current discharge capacity of the corresponding specific group. That is, the discharge priority factor of a specific group can be determined according to the following Equation 2.

[0077] Equation 2

[0078]

[0079] In equation 2, P B is the discharge priority factor for a specific group, y is the number of members in the specific group, and V is the discharge priority factor for a specific group. x SOC x and SOH x These are the voltage, SOC, and SOH of the x-th member of a specific group, respectively. j is a predetermined index greater than 0 (e.g., 1.2), k is a predetermined index greater than 0 (e.g., 0.8), and l is a predetermined index greater than 0 (e.g., 1.5). Each of j, k, and l is preset by testing the test battery pack.

[0080] Alternatively, when at least two third groups are determined, the control circuit 400 may use both the discharge risk factor and the discharge priority factor to set only one of the at least two third groups as the fourth group. For example, any one of the at least two third groups may be set as the fourth group if: (i) the value obtained by dividing the discharge risk factor by the discharge priority factor is the smallest; (ii) the value obtained by dividing the discharge priority factor by the discharge risk factor is the largest; (iii) the value obtained by subtracting the discharge priority factor from the discharge risk factor is the smallest; or (iv) the value obtained by subtracting the discharge risk factor from the discharge priority factor is the largest.

[0081] Figure 3 Another table—Table B (TABLE_B)—is shown, displaying the voltage, SOC, and SOH of each of the multiple battery packs BP_1 to BP_6. For ease of description, Figure 3 The voltages of the first to sixth battery packs (BP_1 to BP_6) arranged in descending order are shown. Figure 3 In the context of a reference SOH of 3%, the sixth battery pack BP_6 has an SOH of less than 90% of the maximum SOH, reaching or exceeding the reference SOH by 85%. Therefore, the control circuit 400 only sets the remaining battery packs BP_1 to BP_5, excluding the sixth battery pack BP_6, as discharge candidates. Figure 3 When describing the contents of this disclosure, it should be noted that references and explanations may be omitted. Figure 2 The aforementioned descriptions overlap.

[0082] The control circuit 400 sets at least one first group from discharge candidates BP_1 to BP_5 by applying grouping rules to discharge candidates BP_1 to BP_5.

[0083] according to Figure 3 Table TABLE_B uses 10V as the reference voltage to determine a total of three first groups according to the grouping rules. That is, the first battery group BP_1, the second battery group BP_2, and the third battery group BP_3 are determined as the first group g#1_1; the second battery group BP_2, the third battery group BP_3, and the fourth battery group BP_4 are determined as another first group g#1_2; and the third battery group BP_3, the fourth battery group BP_4, and the fifth battery group BP_5 are determined as another first group g#1_3.

[0084] The control circuit 400 sets the first group with the largest sum of SOC among the three first groups g#1_1 to g#1_3 as the second group. According to... Figure 3 In table TABLE_B, the sum of the SOCs of the first group g#1_1 is 96%, the sum of the SOCs of another first group g#1_2 is 95%, and the sum of the SOCs of another first group g#1_3 is 96%. Since the two first groups g#1_1 and g#1_3 have the largest sum of SOCs, two of the three first groups g#1_1 to g#1_3, g#1_1 and g#1_3, are respectively set as second groups g#2_1 and g#2_2.

[0085] When Figure 3When at least two second groups g#2_1 and g#2_2 are set, the control circuit 400 sets either of the two second groups g#2_1 and g#2_2 with the largest number of members as the third group. Since the number of members in the second group g#2_1 and the second group g#2_2 is equal to 3, both second groups g#2_1 and g#2_2 are set as the third groups g#3_1 and g#3_2.

[0086] The control circuit 400 can set any one of the at least two third groups g#3_1, g#3_2 with the minimum discharge risk factor (e.g., g#3_1) as the discharge target (see Equation 1).

[0087] Alternatively, the control circuit 400 may set any one of the at least two third groups g#3_1, g#3_2 with the largest discharge priority factor (e.g., g#3_1) as the discharge target (see Equation 2).

[0088] Alternatively, the control circuit 400 may use both the discharge risk factor and the discharge priority factor to set one of at least two third groups g#3_1, g#3_2 (e.g., g#3_1) as the discharge target.

[0089] When the third group g#3_1 is the discharge target, the control circuit 400 can turn on the switch circuits 200_1 to 200_3 corresponding to the battery groups BP_1 to BP_3 of the discharge target g#3_1, and turn off the switch circuits 200_4 to 200_6 corresponding to the remaining battery groups BP_4 to BP_6 other than the discharge target g#3_1.

[0090] Figure 4 and Figure 5 This is an exemplary flowchart of a battery control method according to an embodiment of the present disclosure. Figure 4 and Figure 5 The method can be executed by the battery control device.

[0091] Reference Figures 1 to 5 In step S400, the control circuit 400 determines the voltage, SOH, and SOC of each of the plurality of battery packs BP_1 to BP_6 based on sensing signals indicating the voltage and current of each of the plurality of battery packs BP_1 to BP_6.

[0092] In step S410, the control circuit 400 determines whether there exists any battery pack with a SOH whose difference between the maximum SOH of the plurality of battery packs BP_1 to BP_6 is greater than a reference SOH. If the value of step S410 is "No", step S422 is executed (see [link to step S410]). Figure 2When the value of step S410 is "Yes", proceed to step S424 (see...). Figure 3 ).

[0093] In step S422, the control circuit 400 sets all the multiple battery packs BP_1 to BP_6 as discharge candidates (see...). Figure 2 ).

[0094] In step S424, the control circuit 400 sets the remaining battery packs (e.g., BP_1 to BP_5) as discharge candidates, excluding the battery pack with a SOH whose difference from the maximum SOH is greater than the reference SOH (e.g., BP_6). (See also: [link to discharge circuit]) Figure 3 ).

[0095] In step S430, the control circuit 400 sets at least one first group, each comprising at least one battery pack, by applying grouping rules to all discharge candidates. Figure 2 In this case, three first groups G#1_1 to G#1_3 are set, and in Figure 3 In this case, three first groups g#1_1 to g#1_3 are set.

[0096] In step S440, the control circuit 400 determines whether multiple first groups are set. Figure 2 and Figure 3 In the case where the value of step S440 is "Yes", step S442 is executed. If the value of step S440 is "No", step S444 is executed.

[0097] In step S442, the control circuit 400 sets each of the plurality of first groups with the largest sum of SOC as a second group. Figure 2 In the case of setting up two second groups G#2_1 and G#2_2, and in Figure 3 In this case, two second groups, g#2_1 and g#2_2, are set up.

[0098] In step S444, the control circuit 400 sets a single first group as a discharge group.

[0099] In step S450, the control circuit 400 determines whether to set multiple second groups. Figure 2 and Figure 3 In the case where the value of step S450 is "Yes", step S452 is executed. When the value of step S450 is "No", step S454 is executed.

[0100] In step S452, the control circuit 400 sets each of the multiple second groups with the largest number of members as the third group. Figure 2 In the case of setting a single third group G#3, and in Figure 3 In this case, two third groups, g#3_1 and g#3_2, are set up.

[0101] In step S454, the control circuit 400 sets a single second group as a discharge group.

[0102] In step S460, the control circuit 400 determines whether multiple third groups are set. Figure 3 In the case where the value of step S460 is "Yes", the value of step S462 is executed. Figure 2 In the case where the value of step S460 is "No", the value of step S464 is executed.

[0103] In step S462, the control circuit 400 sets one of the multiple third groups as the discharge target (i.e., the discharge group) based on the discharge risk factor (see Equation 1) and discharge priority factor (see Equation 2) of each of the multiple third groups.

[0104] In step S464, the control circuit 400 sets a single third group as a discharge group.

[0105] In step S470, the control circuit 400 turns on the switching circuit (e.g., 200_1 to 200_3) corresponding to each battery pack of the discharge group (e.g., g#3_1), and turns off the switching circuit (e.g., 200_4 to 200_6) corresponding to the remaining battery packs BP_4 to BP_6 other than the discharge group (e.g., g#3_1).

[0106] The embodiments of the present disclosure described above can be implemented not only by apparatus and method, but also by a program that performs functions corresponding to the configuration of the embodiments of the present disclosure, or by a recording medium on which the program is recorded. Those skilled in the art can easily implement such implementation based on the disclosure of the above embodiments.

[0107] While this disclosure has been described above with respect to a limited number of embodiments and accompanying drawings, it is not limited thereto, and it will be apparent to those skilled in the art that various modifications and alterations can be made to the technical aspects of this disclosure and to the equivalents of the appended claims.

[0108] Furthermore, since those skilled in the art can make many substitutions, modifications and changes to the above-described disclosure without departing from the technical aspects of this disclosure, this disclosure is not limited to the above-described embodiments and drawings, and all or some embodiments can be selectively combined to allow for various modifications.

[0109] (Explanation of reference numerals in the attached image)

[0110] 1: Power Supply System

[0111] 10: Power Conversion System

[0112] 100: Battery System

[0113] BB: Battery Library

[0114] BP: Battery Pack

[0115] BC: Battery cell

[0116] 120: Battery control device

[0117] 200: Switching circuit

[0118] 300: Sensing Circuit

[0119] 310: Voltage sensor

[0120] 320: Current sensor

[0121] 400: Control Circuit

Claims

1. A battery control device, comprising: Multiple switching circuits are connected in series with multiple battery packs in a one-to-one relationship; Multiple sensing circuits are connected to the multiple battery packs in a one-to-one relationship and are configured to generate sensing signals indicating the voltage and current of each battery pack; as well as The control circuit is configured to determine the voltage, state of health (SOH), and state of charge (SOC) of each of the plurality of battery packs based on the sensing signals. The control circuit is configured as follows: When there is no battery pack with a SOH whose difference between the maximum SOH and the reference SOH is greater than that of the plurality of battery packs. Set all of the aforementioned battery packs as discharge candidates. At least one first group comprising at least one battery pack is established by applying a grouping rule to the discharge candidates, wherein the grouping rule specifies that the first group comprises a maximum number of battery packs in which the voltage difference between the maximum and minimum voltages is equal to or less than a reference voltage. In the case of a single first group, the first group is set as the discharge group, and Turn on each switching circuit corresponding to each battery pack included in the discharge group, and turn off the switching circuit corresponding to each remaining battery pack other than the discharge group.

2. A battery control device, comprising: Multiple switching circuits are connected in series with multiple battery packs in a one-to-one relationship; Multiple sensing circuits are connected to the multiple battery packs in a one-to-one relationship and are configured to generate sensing signals indicating the voltage and current of each battery pack; as well as The control circuit is configured to determine the voltage, state of health (SOH), and state of charge (SOC) of each of the plurality of battery packs based on the sensing signals. The control circuit is configured as follows: When there is a battery pack with a SOH whose difference from the maximum SOH is greater than the reference SOH, The remaining battery packs, excluding those with a SOH whose difference from the maximum SOH is greater than the reference SOH, are designated as discharge candidates. At least one first group comprising at least one battery pack is established by applying a grouping rule to the discharge candidates, wherein the grouping rule specifies that the first group comprises a maximum number of battery packs in which the voltage difference between the maximum and minimum voltages is equal to or less than a reference voltage. In the case of a single first group, the first group is set as the discharge group, and Turn on each switching circuit corresponding to each battery pack included in the discharge group, and turn off the switching circuit corresponding to each remaining battery pack other than the discharge group.

3. A battery control device, comprising: Multiple switching circuits are connected in series with multiple battery packs in a one-to-one relationship; Multiple sensing circuits are connected to the multiple battery packs in a one-to-one relationship and are configured to generate sensing signals indicating the voltage and current of each battery pack; as well as The control circuit is configured to determine the voltage, state of health (SOH), and state of charge (SOC) of each of the plurality of battery packs based on the sensing signals. The control circuit is configured as follows: When there is no battery pack with a SOH whose difference between the maximum SOH and the reference SOH is greater than that of the plurality of battery packs. Set all of the aforementioned battery packs as discharge candidates. At least one first group is set up by applying grouping rules to the discharge candidates, which includes at least one battery pack. In the case of multiple first groups, the sum of the SOC of each of the multiple first groups is determined, wherein the sum of the SOC is the sum of the SOCs of all the battery packs included in each first group. The first group with the largest sum of SOC among the plurality of first groups is set as the second group. In the case of a single second group, the second group is set as the discharge group, and Turn on each switching circuit corresponding to each battery pack included in the discharge group, and turn off the switching circuit corresponding to each remaining battery pack other than the discharge group.

4. The battery control device according to claim 3, wherein, The control circuit is configured to: In the case of multiple second groups, the second group with the largest number of members among the multiple second groups is set as the third group, and In the case of a single third group, the third group is set as the discharge group.

5. The battery control device according to claim 4, wherein, The control circuit is configured to: In the case of multiple third groups, determine the discharge risk factor for each of the multiple third groups, and The third group with the lowest discharge risk factor among the plurality of third groups is set as the discharge group.

6. The battery control device according to claim 4, wherein, The control circuit is configured to: In the case of multiple third groups, determine the discharge priority factor for each of the multiple third groups, and The third group with the highest discharge priority factor among the plurality of third groups is set as the discharge group.

7. A battery system comprising a battery control device according to any one of claims 1 to 6.

8. A power supply system comprising the battery system according to claim 7.

9. A battery control method executable by the battery control device according to claim 1, the battery control method comprising: The voltage, SOH, and SOC of each of the plurality of battery packs are determined based on sensing signals indicating the voltage and current of each of the plurality of battery packs; When there is no battery pack with a SOH whose difference between the maximum SOH of the plurality of battery packs and the reference SOH is greater than that of the reference SOH, all of the plurality of battery packs are set as discharge candidates. At least one first group comprising at least one battery pack is set by applying a grouping rule to the discharge candidates, wherein the grouping rule specifies that the first group comprises a maximum number of battery packs in which the voltage difference between the maximum voltage and the minimum voltage is equal to or less than a reference voltage. In the case of a single first group, the first group is designated as the discharge group; and Turn on each switching circuit corresponding to each battery pack included in the discharge group, and turn off each switching circuit corresponding to the remaining battery packs other than the first group.

10. A battery control method executable by the battery control device according to claim 2, the battery control method comprising: The voltage, SOH, and SOC of each of the plurality of battery packs are determined based on sensing signals indicating the voltage and current of each of the plurality of battery packs; When there exists any battery pack with a SOH whose difference from the maximum SOH is greater than the reference SOH. The remaining battery packs, excluding those with a SOH that has a difference between the maximum SOH and the reference SOH, are designated as discharge candidates. At least one first group comprising at least one battery pack is set by applying a grouping rule to the discharge candidates, wherein the grouping rule specifies that the first group comprises a maximum number of battery packs in which the voltage difference between the maximum voltage and the minimum voltage is equal to or less than a reference voltage. In the case of a single first group, the first group is designated as the discharge group; and Turn on each switching circuit corresponding to each battery pack included in the discharge group, and turn off each switching circuit corresponding to the remaining battery packs other than the first group.

11. A battery control method executable by a battery control device according to any one of claims 3 to 6, the battery control method comprising: The voltage, SOH, and SOC of each of the plurality of battery packs are determined based on sensing signals indicating the voltage and current of each of the plurality of battery packs; When there is no battery pack with a SOH whose difference between the maximum SOH of the plurality of battery packs and the reference SOH is greater than that of the reference SOH, all of the plurality of battery packs are set as discharge candidates. At least one first group comprising at least one battery pack is set by applying grouping rules to the discharge candidates. In the case of multiple first groups, the sum of the SOC of each of the multiple first groups is determined, wherein the sum of the SOC is the sum of the SOCs of all the battery packs included in each first group. The first group with the largest sum of SOC among the plurality of first groups is set as the second group. In the case of a single second group, the second group is set as the discharge group, and Turn on each switching circuit corresponding to each battery pack included in the discharge group, and turn off each switching circuit corresponding to the remaining battery packs other than the discharge group.

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