Battery management system, battery device, and equalization method

Abstract

A battery management system connected to a battery module including a plurality of battery cells includes a plurality of cell equalization circuits and a control circuit configured to control the plurality of cell equalization circuits. Each cell equalization circuit includes a DC / DC converter shared by a corresponding odd-numbered battery cell and a corresponding even-numbered battery cell among the plurality of battery cells and having an output terminal connected to a positive terminal of the battery module, a first switch connected between the corresponding odd-numbered battery cell and an input terminal of the DC / DC converter, and a second switch connected between the corresponding even-numbered battery cell and the input terminal.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2025-0015594, filed on February 7, 2025, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

[0003] This disclosure relates to a battery management system, a battery device, and a balancing method. Background Technology

[0004] Electric or hybrid vehicles are automobiles that primarily use batteries as a power source to drive electric motors, and are being actively researched as alternatives to internal combustion engine vehicles, addressing their pollution and energy issues. Furthermore, batteries are used in various external devices beyond electric vehicles.

[0005] Inside a battery, multiple individual cells are connected in series. Voltage deviations between these cells can lead to over-discharge or over-charge, and also reduce their lifespan. To mitigate voltage deviations, a cell balancing circuit is designed within the battery management system.

[0006] Cell-level balancing circuits can be classified into active balancing circuits and passive balancing circuits. In traditional active balancing circuits, one DC / DC converter is connected to one battery cell. Therefore, the size of the battery management system and the cell cost increase due to the large number of DC / DC converters. Furthermore, since traditional active balancing circuits only balance even-numbered or odd-numbered battery cells, components used for balancing odd-numbered cells may be wasted when balancing even-numbered cells, and vice versa. Summary of the Invention

[0007] Technical issues

[0008] Some embodiments may provide a battery management system, battery device, and balancing method capable of efficiently performing active balancing.

[0009] Technical solution

[0010] According to some embodiments, a battery management system connected to a battery module comprising multiple battery cells may include multiple cell balancing circuits and a control circuit configured to control the multiple cell balancing circuits. Each of the multiple cell balancing circuits may include: a DC / DC converter shared by corresponding odd-numbered and even-numbered battery cells among the multiple battery cells, the output terminal of the DC / DC converter being connected to the positive terminal of the battery module; a first switch connected between the corresponding odd-numbered battery cell and the input terminal of the DC / DC converter; and a second switch connected between the corresponding even-numbered battery cell and the input terminal.

[0011] According to some embodiments, a battery device may include: a battery module comprising a plurality of battery cells; a plurality of cell equalization circuits; and a control circuit configured to control the plurality of cell equalization circuits. Each of the plurality of cell equalization circuits may be shared by a corresponding odd-numbered battery cell and a corresponding even-numbered battery cell among the plurality of battery cells, and may include a DC / DC converter whose output terminal is connected to the positive terminal of the battery module, and may be configured to, in response to control by the control circuit, equalize one of the corresponding odd-numbered battery cells and the corresponding even-numbered battery cell via the DC / DC converter, and then equalize the other.

[0012] According to some embodiments, a method for balancing a battery module comprising multiple battery cells may include: discharging a first group of odd-numbered battery cells among the multiple battery cells to charge the battery module; discharging the battery module to charge the odd-numbered battery cells after discharging the odd-numbered battery cells; discharging an even-numbered battery cell group among the multiple battery cells to charge the battery module; and discharging the battery module to charge the even-numbered battery cells after discharging the even-numbered battery cells. Attached Figure Description

[0013] Figure 1 This is a block diagram illustrating a battery device according to some embodiments.

[0014] Figure 2 This is a diagram illustrating a battery device according to some embodiments.

[0015] Figure 3 , Figure 4 , Figure 5 and Figure 6 This is a diagram illustrating the equalization operation of a battery device according to some embodiments.

[0016] Figure 7 This is a diagram illustrating a single-unit equalization circuit according to some embodiments.

[0017] Figure 8This is a diagram illustrating a single-unit equalization circuit according to some embodiments.

[0018] Figure 9 This is a flowchart illustrating an balancing method according to some embodiments. Detailed Implementation

[0019] In the following detailed description, only certain embodiments of the invention are shown and described by way of illustration only. Those skilled in the art will recognize that the described embodiments can be modified in various different ways without departing from the spirit or scope of the invention. Therefore, the drawings and descriptions should be considered illustrative in nature and not restrictive. Throughout the specification, the same reference numerals denote the same elements.

[0020] When a component is described as "connected to" another component, it should be understood that the component can be directly connected to the other component, or connected to the other component through a third component. On the other hand, when a component is described as "directly connected to" another component, it should be understood that the component is connected to the other component without any third component.

[0021] As used herein, the singular form may be intended to include the plural form as well, unless an explicit expression such as “a” or “single” is used.

[0022] In the flowchart described with reference to the accompanying drawings, the order of operations or steps can be changed, several operations or steps can be combined, a certain operation or step can be split, and a specific operation or step may not be performed.

[0023] Figure 1 This is a block diagram illustrating a battery device according to some embodiments.

[0024] refer to Figure 1 The battery device 100 may include a battery module 110, a battery management system (BMS) 120, and switches 131 and 132. The battery device 100 can be electrically connected to an external device via a positive connection terminal P+ and a negative connection terminal P-. In some embodiments, when the external device is a load, the battery device 100 can be discharged by operating as a power source supplying power to the load. When the external device is a charger, the battery device 100 can be charged by receiving external power from the charger. In some embodiments, the external device operating as a load may be, for example, an electronic device, a mobile device, or an energy storage system (ESS), and the mobile device may be, for example, a car such as an electric vehicle, a hybrid vehicle, or a smart mobility tool. The battery device 100 may be referred to as a battery pack.

[0025] Battery module 110 may include multiple battery cells (not shown). In some embodiments, the multiple battery cells may be connected in series. In some embodiments, battery device 100 may include multiple battery modules 110. The multiple battery cells of battery module 110 may each be connected to battery management system 120 via wiring.

[0026] Switch 131 may be connected between the positive terminal B+ and the positive connection terminal P+ of battery module 110, and switch 132 may be connected between the negative terminal B- and the negative connection terminal P- of battery module 110. Switches 131 and 132 may be controlled by battery management system 120 to control the connection between battery device 100 and external devices. In some embodiments, switches 131 and 132 may each include a contactor comprising a relay. In some embodiments, switches 131 and 132 may each include an electrical switch such as a transistor. In some embodiments, battery device 100 may also include a drive circuit (not shown) that drives each of switches 131 and 132 in response to a control signal from battery management system 120.

[0027] The battery management system 120 can collect and analyze information about individual battery cells to control operations such as charging and discharging, cell balancing, and cell protection. The battery management system 120 may include an balancing circuit 121, a battery monitoring circuit 122, and a processor 123.

[0028] The battery monitoring circuit 122 can be connected via wiring to each of the plurality of battery cells included in the battery module 110, and can monitor the state of the battery cells (e.g., cell voltage). In some embodiments, the battery monitoring circuit 122 may include a plurality of battery monitoring circuits 122 corresponding to the plurality of battery modules 110 respectively. In some embodiments, one battery monitoring circuit 122 may correspond to two or more battery modules 110, or two or more battery monitoring circuits 122 may correspond to one battery module 110. In some embodiments, the battery monitoring circuit 122 may be provided as an integrated circuit (IC), and the battery monitoring circuit 122 provided as an IC is referred to as a battery monitoring IC (BMIC).

[0029] The equalization circuit 121 can equalize multiple battery cells based on the voltage of the individual battery cells measured by the battery monitoring circuit 122. The equalization circuit 121 may include multiple cell equalization circuits (not shown), and each cell equalization circuit can be connected to two corresponding battery cells among the multiple battery cells to perform equalization on the two corresponding battery cells. Therefore, two battery cells can share one cell equalization circuit. In some embodiments, each cell equalization circuit can be shared by adjacent odd-numbered and even-numbered battery cells, and can perform equalization on one of the odd-numbered and even-numbered battery cells, and then perform equalization on the other battery cell. While each cell equalization circuit performs equalization on odd-numbered battery cells, other cell equalization circuits can also perform equalization on their corresponding odd-numbered battery cells, and while each cell equalization circuit performs equalization on even-numbered battery cells, other cell equalization circuits can also perform equalization on their corresponding even-numbered battery cells.

[0030] Processor 123 can receive monitoring information from battery monitoring circuit 122 and can control the operation of battery monitoring circuit 122. Processor 123 can control the operation of switches 131 and 132. Processor 123 can be a processing circuit system and can be, for example, a microcontroller unit (MCU).

[0031] In some embodiments, the battery monitoring circuit 122 and / or the processor 123 may operate as a control circuit for controlling the operation of the equalization circuit 121.

[0032] Figure 2 The diagram illustrates a battery device according to some embodiments, and Figure 3 , Figure 4 , Figure 5 and Figure 6 This is a diagram illustrating the equalization operation of a battery device according to some embodiments.

[0033] refer to Figure 2 The battery device 200 may include a battery module 210, a battery monitoring circuit 220, and multiple cell equalization circuits 2301, 2302, ..., 230 N / 2 And control circuit 240.

[0034] Battery module 210 may include multiple battery cells C1, C2, ..., C1 connected in series. N Multiple battery cells C1–C N The last battery cell in the middle (e.g., the topmost battery cell) C N The positive electrode can be connected to the positive terminal B+ of the battery module 210, and multiple battery cells C1–C NThe negative terminal of the first battery cell (e.g., the bottommost battery cell) C1 can be connected to the negative terminal B- of the battery module 210.

[0035] The battery monitoring circuit 220 can be connected to multiple battery cells C1–C via wiring. N The positive and negative electrodes can be monitored, and the C1–C of each battery cell can be monitored. N The voltage. In some embodiments, the battery monitoring circuit 220 may be provided as a BMIC 220.

[0036] 230 per unit equalization circuit i It can be connected to multiple battery cells C1–C N The two corresponding battery cells, namely the odd-numbered battery cell C 2i-1 and the corresponding even-numbered battery cell C 2i And it can be used for two battery cells C 2i-1 and C 2i Perform balancing. Here, i is an integer between 1 and N / 2.

[0037] 230 per unit equalization circuit i It may include a DC / DC converter 231 i And DC / DC converter 231 i It can be a dual-input, single-output DC / DC converter. In some embodiments, DC / DC converter 231 i It can be an inductor-based DC / DC converter. In DC / DC converter 231 i In the dual-input configuration, one input (the first input) can be connected to the corresponding odd-numbered battery cell C. 2i-1 To receive odd-numbered battery cells C 2i-1 The voltage is used as an input, and another input (the second input) can be connected to the corresponding even-numbered battery cell C. 2i To receive even-numbered battery cells C 2i The voltage is used as the input. DC / DC converter 231 i The output can be connected to the positive terminal B+ of battery module 210, i.e., the last battery cell C. N The positive electrode is B+.

[0038] In some embodiments, each individual equalization circuit 230 i It may also include: switch 232 i It is connected to DC / DC converter 231 i The negative input of the first input in the dual-input system is related to the corresponding odd-numbered battery cell C. 2i-1 Between the negative terminals; and switch 233 iIts connection is to the positive input of the first input and the corresponding odd-numbered battery cell C. 2i-1 Between the positive terminals. Each individual equalization circuit has 230. i It may also include: switch 234 i It is connected to DC / DC converter 231 i The negative input of the second input in the dual-input system is related to the even-numbered battery cell C. 2i Between the negative terminals; and switch 235 i Its connection is to the positive input of the second input and the corresponding even-numbered battery cell C. 2i Between the positive and negative terminals. When switch 232 i and 233 i When switched on, DC / DC converter 231 i Odd-numbered battery cells C can be used 2i-1 The voltage is used as an input for operation, and then the voltage of the battery module 210 is used as an input for operation. When switch 234 i and 235 i When switched on, DC / DC converter 231 i Even-numbered battery cells C can be used 2i The switch operates with the voltage of the battery module 210 as an input, and then operates with the voltage of the battery module 210 as an input. In some embodiments, switch 232 i 233 i 234 i and 235 i It can be used as a DC / DC converter 231 i The components are provided.

[0039] The control circuit 240 can be based on the battery cells C1–C monitored by the battery monitoring circuit 220. N The voltage is used to control the individual unit equalization circuit 2301–230 N / 2 In some embodiments, the control circuit 240 can control the individual equalization circuits 2301–230. N / 2 This makes the battery cell C1–C N Discharged to battery cell C1–C N The lowest voltage among the voltages.

[0040] Control circuit 240 can control individual equalization circuits 2301–230 N / 2 First, we examine the odd-numbered battery cells C1, C3, ..., C... N-1 Groups and even-numbered battery cells C2, C4, ..., C N The equalization process performs equalization on one group of the groups and then on another group. For example, control circuit 240 can control individual equalization circuits 2301–230. N / 2Only for odd-numbered battery cells C1, C3, and C N-1 Perform balancing, and then only balance the even-numbered battery cells C2, C4, and C5. N Equalization is performed. As another example, control circuit 240 can control individual equalization circuits 2301–230. N / 2 Only for even-numbered battery cells C2, C4, and C N Perform balancing, and then only balance the odd-numbered battery cells C1, C3, and C4. N-1 To achieve equilibrium.

[0041] When considering odd-numbered battery cells C1, C3, and C N-1 When performing equilibrium, such as Figure 3 As shown, the control circuit 240 can control the individual equalization circuit 230. i DC / DC converter 231 i This makes the odd-numbered battery cell C 2i-1 Discharged (S310). From battery cell C 2i-1 The energy from the discharge can be transferred to the positive terminal B+ of the battery module 210, i.e., the topmost battery cell C. N The positive electrode is charged into the battery module 210 (S320). For example, the energy discharged from the odd-numbered battery cells can be charged into the multiple battery cells C1–C included in the battery module 210. N In the middle. Next, as... Figure 4 As shown, the control circuit 240 can control the DC / DC converter 231. i This causes battery module 210 to discharge (S410). The energy discharged from battery module 210 can be transferred to the corresponding odd-numbered battery cell C. 2i-1 And it can be used for battery cells C1–C N Charging causes the battery cells C1–C to... N The voltage becomes uniform (S420). In this case, the odd-numbered battery cell C is connected. 2i-1 Switch 232 i and 233 i It can be switched on and connected to even-numbered battery cells C. 2i Switch 234 i and 235 i It can be turned off. In some embodiments, when battery cell C... 2i-1 When discharged, the single-unit equalization circuit 230 i DC / DC converter 231 i It can operate in dual-input single-output boost mode, and when the battery cell C 2i-1 When being charged, DC / DC converter 231 iIt can operate in single-input dual-output buck mode.

[0042] Similarly, when the even-numbered battery cells C2, C4, and C... N When performing equilibrium, such as Figure 5 As shown, the control circuit 240 can control the individual equalization circuit 230. i DC / DC converter 231 i This makes even-numbered battery cells C 2i Discharged (S510). From battery cell C 2i The energy from the discharge can be transferred to the positive terminal B+ of the battery module 210, i.e., the topmost battery cell C. N The positive electrode is charged into the battery module 210 (S520). For example, the energy discharged from even-numbered battery cells can be charged into the multiple battery cells C1–C included in the battery module 210. N In the middle. Next, as... Figure 6 As shown, the control circuit 240 can control the DC / DC converter 231. i This causes battery module 210 to discharge (S610). The energy discharged from battery module 210 can be transferred to the corresponding odd-numbered battery cell C. 2i And it can be used for battery cells C1–C N Charging causes the battery cells C1–C to... N The voltage becomes uniform (S620). In some embodiments, in the battery cell C 2i When discharged, the single-unit equalization circuit 230 i DC / DC converter 231 i It can operate in dual-input single-output boost mode, and in battery cell C 2i When being charged, DC / DC converter 231 i It can operate in single-input dual-output buck mode.

[0043] Despite Figures 3 to 6 The image shows odd-numbered battery cells C1, C3, and C4. N-1 The battery cell C 2i-1 And even-numbered battery cells C2, C4 and C N The battery cell C 2i As a representative, but when considering the battery cell C 2i-1 During balancing, the remaining odd-numbered battery cells can also be balanced simultaneously, and when balancing battery cell C... 2i During balancing, the remaining even-numbered battery cells can also be balanced simultaneously.

[0044] In some embodiments, the control circuit 240 may be a processor of the battery management system (e.g., Figure 1(123 in the text). In some embodiments, the battery monitoring circuit 220 may operate as the control circuit 240.

[0045] As mentioned above, due to the odd-numbered battery cell C 2i-1 and even-numbered battery cells C 2i Common DC / DC converter 231 i And in odd-numbered battery cells C 2i-1 While being balanced, even-numbered battery cells C 2i It can be unbalanced, and in even-numbered cell C 2i While being balanced, odd-numbered battery cells C 2i-1 It can be unbalanced. As a result, the number of DC / DC converters 231 can be reduced. i The number of cells is increased, thereby reducing the unit cost and size of the battery management system. In some embodiments, the entire battery module 210 utilizes cells C... 2i-1 Or C 2i After the energy from the discharge is recharged, the energy that was charged into the battery module 210 can be reused to power the battery cell C. 2i-1 Or C 2i Charging makes the voltage of the multiple battery cells more uniform.

[0046] Figure 7 This is a diagram illustrating a single-unit equalization circuit according to some embodiments.

[0047] refer to Figure 7 The individual cell equalization circuit 700 may include a boost converter-type DC / DC converter 710. The individual cell equalization circuit 700 can be connected to multiple battery cells (e.g., Figure 2 C1–C N The corresponding odd-numbered battery cells (e.g., C) 2i-1 ) and the corresponding even-numbered battery cells (e.g., C 2i ), and can control the C of individual battery cells 2i-1 and C 2i The balance.

[0048] DC / DC converter 710 may include an inductor 711, switches 712 and 713, and a capacitor 714. Inductor 711 may be connected between the input terminal IN of DC / DC converter 710 and node N1. For example, a first terminal of inductor 711 may be connected to the input terminal IN, and a second terminal of inductor 711 may be connected to node N1. Switch 712 may be connected between node N1 and a ground terminal, and switch 713 may be connected between node N1 and the output terminal OUT of DC / DC converter 710. In some embodiments, each of switches 712 and 713 may be a transistor. For example, each of switches 712 and 713 may be an N-channel field-effect transistor (FET). In this case, the drain of FETs 712 and 713 may be connected to node N1, the source of FET 712 may be connected to the ground terminal, and the source of FET 713 may be connected to the output terminal OUT. Switches 712 and 713 may be controlled by a control circuit (e.g., Figure 2 Controlled by control circuit 240. In some embodiments, the single-unit equalization circuit 700 may further include a driver 715, which drives switches 712 and 713 according to the control of control circuit 240. Capacitor 714 may be connected between output terminal OUT and ground terminal. For example, a first terminal of capacitor 714 may be connected to output terminal OUT, and a second terminal of capacitor 714 may be connected to ground terminal. Output terminal OUT may be connected to battery module (e.g., ...). Figure 2 The positive extreme of 210 in the middle.

[0049] The single-cell equalization circuit 700 may further include: a switch 721 connected to the odd-numbered battery cell C. 2i-1 Between the negative terminal and the ground terminal; switch 722, which is connected to the odd-numbered battery cell C. 2i-1 The positive terminal is connected between the positive terminal and the input terminal IN of the DC / DC converter 710; switch 723 is connected to the even-numbered battery cell C. 2i Between the negative terminal and the ground terminal; and switch 724, which is connected to the even-numbered battery cell C. 2i The positive terminal is connected to the input terminal IN of the DC / DC converter 710.

[0050] In the case of odd-numbered battery cells C 2i-1 During balancing, the voltage of battery module 210 is higher than that of individual battery cell C. 2i-1The voltage is such that the control circuit 240 can initially operate the DC / DC converter 710 in boost mode. In response to the control of the control circuit 240, switches 721 and 722 can be turned on, and switch 712 of the DC / DC converter 710 can be turned on. In this case, switches 723, 724, and 713 can be in the off state. Then, with the battery cell C... 2i-1 When discharged, current can be supplied to inductor 711, and the current in inductor 711 can increase. Next, in response to the control of control circuit 240, switch 712 of DC / DC converter 710 can be turned off, and switch 713 can be turned on. Then, through the energy charged into inductor 711, the battery cell C... 2i-1 The voltage can be discharged, and the battery module 210 can be charged.

[0051] Next, the control circuit 240 can operate the DC / DC converter 710 in buck mode to discharge the energy of the battery module 210 to the odd-numbered battery cells C. 2i-1 In response to the control of the control circuit 240, switches 721 and 722 can be turned on, and switch 713 of the DC / DC converter 710 can be turned on. In this case, switches 723, 724, and 712 can be in the off state. Then, as the battery module 210 is discharged, the current in inductor 711 can increase. In some embodiments, the current can flow through the body diode of switch 713. Next, in response to the control of the control circuit 240, switch 713 of the DC / DC converter 710 can be turned off, and switch 712 can be turned on. Then, the energy charged into inductor 711 can be used to charge the battery cell C. 2i-1 Charging. In some embodiments, current may flow through the body diode of switch 712.

[0052] In even-numbered battery cells C 2i Under the condition of balancing, compared with the odd-numbered cell C 2i-1 Similarly, for equalization, control circuit 240 can first operate DC / DC converter 710 in boost mode. In response to the control of control circuit 240, switches 723 and 724 can be turned on, and switch 712 of DC / DC converter 710 can be turned on. In this case, switches 721, 722, and 713 can be in the off state. Then, with the battery cell C... 2i When discharged, current can be supplied to inductor 711, and the current in inductor 711 can increase. Next, in response to the control of control circuit 240, switch 712 of DC / DC converter 710 can be turned off, and switch 713 can be turned on. Then, through the energy charged into inductor 711, the battery cell C... 2iThe voltage can be discharged, and the battery module 210 can be charged.

[0053] Next, the control circuit 240 can operate the DC / DC converter 710 in buck mode to discharge the energy of the battery module 210 to the even-numbered battery cells. In response to the control of the control circuit 240, switches 723 and 724 can be turned on, and switch 713 of the DC / DC converter 710 can be turned on. In this case, switches 721, 722, and 712 can be in the off state. Then, as the battery module 210 is discharged, the current in the inductor 711 can increase. Next, in response to the control of the control circuit 240, switch 713 of the DC / DC converter 710 can be turned off, and switch 712 can be turned on. Then, the energy charged into the inductor 711 can be used to charge the battery cells C. 2i Charge.

[0054] Figure 8 This is a diagram illustrating a single-unit equalization circuit according to some embodiments.

[0055] refer to Figure 8 The individual cell equalization circuit 800 may include a buck-boost type DC / DC converter 810. The individual cell equalization circuit 800 can be connected to multiple battery cells (e.g., Figure 2 C1–C N The corresponding odd-numbered battery cell (e.g., C) in ) 2i-1 ) and the corresponding even-numbered battery cells (e.g., C 2i ), and can control the C of individual battery cells 2i-1 and C 2i The balance.

[0056] DC / DC converter 810 may include an inductor 811, switches 812, 813, 814, and 815, and a capacitor 816. Inductor 811 may be connected between a first node N1 and a second node N2. For example, a first terminal of inductor 811 may be connected to the second node N2, and a second terminal of inductor 811 may be connected to the first node N1. Switch 812 may be connected between the first node N1 and a ground terminal, and switch 813 may be connected between the first node N1 and the output terminal OUT of DC / DC converter 810. Switch 814 may be connected between the input terminal IN of DC / DC converter 810 and the second node N2, and switch 815 may be connected between the input terminal IN and a ground terminal. In some embodiments, switch 815 may be omitted. In some embodiments, each of switches 812, 813, 814, and 815 may be a transistor. For example, each of switches 812, 813, 814, and 815 may be an N-channel FET. In this configuration, the drains of FETs 812 and 813 can be connected to the first node N1, the source of FET 814 and the drain of FET 815 can be connected to the input terminal IN, the drain of FET 814 can be connected to the second node N2, the sources of FETs 812 and 815 can be connected to the ground terminal, and the source of FET 813 can be connected to the output terminal OUT. Switches 812, 813, 814, and 815 can be controlled by a control circuit (e.g., Figure 2 Controlled by control circuit 240. In some embodiments, the individual equalization circuit 800 may further include a driver 817, which drives switches 812, 813, 814, and 815 according to the control of control circuit 240. Capacitor 816 may be connected between output terminal OUT and ground terminal. For example, a first terminal of capacitor 816 may be connected to output terminal OUT, and a second terminal of capacitor 816 may be connected to ground terminal. Output terminal OUT may be connected to battery module (e.g., ...). Figure 2 The positive extreme of 210 in the middle.

[0057] The single-cell equalization circuit 800 may further include: a switch 821 connected to the odd-numbered battery cell C. 2i-1 Between the negative terminal and the ground terminal; switch 822, which is connected to the odd-numbered battery cell C. 2i-1 The positive terminal is connected between the positive terminal and the input terminal IN of the DC / DC converter 810; switch 823 is connected to the even-numbered battery cell C. 2i Between the negative terminal and the ground terminal; and switch 824, which is connected to the even-numbered battery cell C. 2i The positive terminal is connected to the input terminal IN of the DC / DC converter 810.

[0058] In the case of odd-numbered battery cells C2i-1 During balancing, the voltage of battery module 210 is higher than that of individual battery cell C. 2i-1 Given the voltage, control circuit 240 can initially operate DC / DC converter 810 in boost mode. In response to the control of control circuit 240, switches 821 and 822 can be turned on, and switches 812 and 814 of DC / DC converter 810 can be turned on. In this case, switches 823, 824, 813, and 815 can be in the off state. Then, with the battery cell C... 2i-1 When discharged, current can be supplied to inductor 811, and the current in inductor 811 can increase. In some embodiments, current can flow through the body diode of switch 814. Next, in response to the control of control circuit 240, switch 812 of DC / DC converter 810 can be turned off, and switch 813 can be turned on. Then, through the energy charged into inductor 811, the battery cell C... 2i-1 The voltage can be discharged, and the battery module 210 can be charged.

[0059] Next, control circuit 240 can operate DC / DC converter 810 in buck mode to discharge energy from battery module 210 to odd-numbered battery cells. In response to control by control circuit 240, switches 821 and 822 can be turned on, and switches 813 and 814 of DC / DC converter 810 can be turned on. In this case, switches 823, 824, 812, and 815 can be in the off state. Then, as battery module 210 is discharged, the current in inductor 811 can increase. In some embodiments, current can flow through the body diode of switch 813. Next, in response to control by control circuit 240, switch 813 of DC / DC converter 810 can be turned off, and switch 812 can be turned on. Then, the energy charged into inductor 811 can be used to charge battery cells C. 2i-1 Charging. In some embodiments, current may flow through the body diode of switch 812.

[0060] In even-numbered battery cells C 2i Under the condition of balancing, compared with the odd-numbered cell C 2i-1 Similarly, for equalization, control circuit 240 can first operate DC / DC converter 810 in boost mode. In response to the control of control circuit 240, switches 823 and 824 can be turned on, and switches 812 and 814 of DC / DC converter 810 can be turned on. In this case, switches 821, 822, 813, and 815 can be in the off state. Then, with the battery cell C... 2iWhen discharged, current can be supplied to inductor 811, and the current in inductor 811 can increase. Next, in response to the control of control circuit 240, switch 812 of DC / DC converter 810 can be turned off, and switch 813 can be turned on. Then, through the energy charged into inductor 811, the battery cell C... 2i The voltage can be discharged, and the battery module 210 can be charged.

[0061] Next, the control circuit 240 can operate the DC / DC converter 810 in buck mode to discharge the energy of the battery module 210 to the even-numbered battery cells. In response to the control of the control circuit 240, switches 823 and 824 can be turned on, and switches 813 and 814 of the DC / DC converter 810 can be turned on. In this case, switches 821, 822, 812, and 815 can be in the off state. Then, as the battery module 210 is discharged, the current in the inductor 811 can increase. Next, in response to the control of the control circuit 240, switch 813 of the DC / DC converter 810 can be turned off, and switch 812 can be turned on. Then, the energy charged into the inductor 811 can be used to charge the battery cells C. 2i Charge.

[0062] Figure 9 This is a flowchart illustrating an balancing method according to some embodiments.

[0063] refer to Figure 9 The control circuit of the battery management system can operate the DC / DC converter in boost mode to discharge one of the odd-numbered and even-numbered battery cell groups (e.g., the odd-numbered battery cell group) to charge the battery module (S910). The control circuit can also operate the DC / DC converter in buck mode to discharge the battery module to charge the odd-numbered battery cells (S920).

[0064] The control circuit can operate the DC / DC converter in boost mode to discharge one of the odd-numbered battery cell groups and the other of the even-numbered battery cell groups (e.g., the even-numbered battery cell group) to charge the battery module (S930). The control circuit can also operate the DC / DC converter in buck mode to discharge the battery module to charge the even-numbered battery cells (S940).

[0065] While the invention has been described in conjunction with embodiments now considered practical, it should be understood that the invention is not limited to the disclosed embodiments. Rather, the invention is intended to cover various modifications and equivalent arrangements contained within the spirit and scope of the appended claims.

Claims

1. A battery management system connected to a battery module comprising a plurality of battery cells, the battery management system comprising: Multiple single-unit equalization circuits; as well as A control circuit, configured to control the plurality of individual equalization circuits, Each of the plurality of individual equalization circuits includes: A DC / DC converter is shared by corresponding odd-numbered and even-numbered battery cells among the plurality of battery cells, and the output terminal of the DC / DC converter is connected to the positive terminal of the battery module. A first switch is connected between the corresponding odd-numbered battery cell and the input terminal of the DC / DC converter; and A second switch is connected between the corresponding even-numbered battery cell and the input terminal.

2. The battery management system according to claim 1, wherein, The first switch includes a switch connected between the positive terminal of the corresponding odd-numbered battery cell and the input terminal, and a switch connected between the negative terminal of the corresponding odd-numbered battery cell and the ground terminal. The second switch includes a switch connected between the positive terminal of the corresponding even-numbered battery cell and the input terminal, and a switch connected between the negative terminal of the corresponding even-numbered battery cell and the ground terminal.

3. The battery management system according to claim 1, wherein, The control circuit is configured to equalize one of the corresponding odd-numbered battery cells and the corresponding even-numbered battery cells via the DC / DC converter, and then equalize the other.

4. The battery management system according to claim 3, wherein, The control circuit is configured as follows: When balancing the corresponding odd-numbered battery cells, the first switch is turned on and the second switch is turned off. as well as When balancing the corresponding even-numbered battery cells, the second switch is turned on and the first switch is turned off.

5. The battery management system according to claim 3, wherein, The control circuit is configured as follows: When balancing the corresponding odd-numbered battery cells, the DC / DC converter is operated in boost mode and then in buck mode. as well as When balancing the corresponding even-numbered battery cells, the DC / DC converter operates in boost mode and then in buck mode.

6. The battery management system according to claim 3, wherein, The DC / DC converter is configured to: when equalizing the corresponding odd-numbered battery cells, discharge the corresponding odd-numbered battery cells to charge the battery module, and then discharge the battery module to charge the corresponding odd-numbered battery cells. The DC / DC converter is configured to: discharge the corresponding even-numbered battery cell to charge the battery module when equalizing the corresponding even-numbered battery cell, and then discharge the battery module to charge the corresponding even-numbered battery cell.

7. The battery management system according to claim 1, wherein, The DC / DC converter includes: An inductor, the inductor being connected between the input terminal and the node; A third switch is connected between the node and the grounding terminal; A fourth switch, the fourth switch being connected between the node and the output terminal; and A capacitor is connected between the output terminal and the ground terminal.

8. The battery management system according to claim 7, wherein, The control circuit is configured to execute sequentially during equalization: The operation of turning on the third switch and turning off the fourth switch, and then turning off the third switch and turning on the fourth switch; and The operation of turning off the third switch and turning on the fourth switch, and then turning off the third switch and turning on the fourth switch.

9. The battery management system according to claim 1, wherein, The DC / DC converter includes: An inductor connected between a first node and a second node; A third switch is connected between the first node and the grounding terminal; A fourth switch is connected between the first node and the output terminal; A fifth switch, wherein the fifth switch is connected between the second node and the input terminal; and A capacitor is connected between the output terminal and the ground terminal.

10. The battery management system according to claim 9, wherein, The control circuit is configured to execute sequentially during equalization: The operation of turning on the third switch and the fifth switch and turning off the fourth switch, and then turning off the third switch and turning on the fourth switch and the fifth switch; and The operation of turning off the third switch and turning on the fourth and fifth switches, and then turning on the third and fifth switches and turning off the fourth switch.

11. A battery device, comprising: A battery module, the battery module comprising multiple battery cells; Multiple single-unit equalization circuits; as well as A control circuit, configured to control the plurality of individual equalization circuits, Each of the plurality of individual cell equalization circuits is shared by the corresponding odd-numbered battery cell and the corresponding even-numbered battery cell among the plurality of battery cells, including a DC / DC converter whose output terminal is connected to the positive terminal of the battery module, and is configured to, in response to the control of the control circuit, equalize one of the corresponding odd-numbered battery cell and the corresponding even-numbered battery cell through the DC / DC converter, and then equalize the other.

12. The battery device according to claim 11, wherein, The control circuit is configured as follows: When balancing the corresponding odd-numbered battery cells, the DC / DC converter is operated in boost mode and then in buck mode. as well as When balancing the corresponding even-numbered battery cells, the DC / DC converter operates in boost mode and then in buck mode.

13. The battery device according to claim 11, wherein, The DC / DC converter is configured to: when equalizing the corresponding odd-numbered battery cells, discharge the corresponding odd-numbered battery cells to charge the battery module, and then discharge the battery module to charge the corresponding odd-numbered battery cells. The DC / DC converter is configured to: discharge the corresponding even-numbered battery cell to charge the battery module when equalizing the corresponding even-numbered battery cell, and then discharge the battery module to charge the corresponding even-numbered battery cell.

14. A method for balancing a battery module comprising multiple battery cells, the method comprising: Discharge the first group of odd-numbered battery cells from the plurality of battery cells to charge the battery module; After the odd-numbered battery cell group has discharged, the battery module is discharged to charge the odd-numbered battery cell group. Discharge the even-numbered battery cells among the plurality of battery cells to charge the battery module; as well as After discharging the even-numbered battery cells, the battery module is discharged to charge the even-numbered battery cells.

15. The balancing method according to claim 14, wherein, The odd-numbered battery cells in the odd-numbered battery cell group and the even-numbered battery cells in the even-numbered battery cell group that correspond to the odd-numbered battery cells share a single DC / DC converter. Discharging the odd-numbered battery cells includes operating the DC / DC converter in boost mode. Discharging the even-numbered battery cells includes operating the DC / DC converter in the boost mode, and Discharging the battery module includes operating the DC / DC converter in buck mode.

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