Apparatus and method for controlling a battery

Abstract

An apparatus for controlling a battery pack, the battery pack comprising a plurality of modules, each module comprising a plurality of cells connected in series, the apparatus can comprise: a selection circuit comprising one or more switches connected to a positive terminal of each cell and one or more switches connected to a negative terminal of each cell; a resonant circuit comprising one or more inductors and one or more capacitors, one end of the resonant circuit connected to a first node and the other end of the resonant circuit connected to a second node; and a controller configured to control the plurality of switches in the selection circuit and the one or more switches in the resonant circuit to measure impedance of selected cells among the plurality of cells or to perform charge equalization among the plurality of cells or among the plurality of modules.

Description

Technical Field

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2024-0118296, filed on September 2, 2024, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a battery control device and method, and more particularly to a battery control device and method comprising circuitry capable of both charge balancing and battery impedance measurement. Background Technology

[0003] Rechargeable and reusable secondary batteries are manufactured into battery modules or battery packs by connecting multiple individual cells in series based on the required output capacity, thus serving as a power source for a variety of applications. These batteries are used in small, high-tech electronic devices such as smartphones, as well as in various fields including electric bicycles, electric vehicles, and energy storage systems (ESS).

[0004] A battery pack is a structure composed of multiple battery cells. Overvoltage, overcurrent, and overheating in some battery cells can impair the safety and operating efficiency of the battery pack, making the detection of these defects necessary. Therefore, battery packs are typically equipped with a battery management system (BMS), which measures the voltage of each battery cell and monitors and controls the voltage state of the cells based on these measurements.

[0005] Meanwhile, the performance of individual cells within a battery pack can vary due to various reasons, leading to voltage imbalances among the cells. If a battery pack is used with voltage imbalances among its cells, its performance becomes dependent on the degraded cells, thus limiting the overall performance of the battery pack. In other words, cell imbalance reduces the usable capacity / power of the battery.

[0006] Furthermore, degraded battery cells tend to deteriorate further, thus accelerating cell aging. If these degraded cells are left untreated, the lifespan of the battery pack will be rapidly reduced.

[0007] To address this issue of cell imbalance, passive balancing or active balancing is typically used. Passive balancing selectively connects resistors across the cell terminals to discharge the cell, while active balancing transfers power from high-voltage cells to low-voltage cells via capacitors.

[0008] Meanwhile, methods for measuring and analyzing battery impedance are frequently used to assess battery degradation or anomalies. To measure battery impedance, circuitry is typically added to measure the impedance of each individual cell to obtain the necessary measurements, which are then used to calculate the impedance.

[0009] Therefore, the equalization of individual unit imbalances and impedance measurements was previously performed using separate devices or circuits.

[0010] Among the prior art documents related to this invention, KR 10-2016-0064089 A is somewhat relevant. Summary of the Invention

[0011] Technical issues

[0012] To eliminate one or more problems of the related art, embodiments of this disclosure provide a battery control device including control circuitry capable of performing both inter-cell / inter-module balancing and battery impedance measurement.

[0013] To eliminate one or more problems of the related technology, embodiments of this disclosure also provide a battery pack including a battery control device.

[0014] Technical solution

[0015] To achieve the objectives of this disclosure, an apparatus for controlling a battery pack includes multiple modules, each module including multiple cells connected in series. The apparatus may include: a selection circuit including one or more switches connected to the positive terminal of each cell and one or more switches connected to the negative terminal of each cell; a resonant circuit including one or more inductors and one or more capacitors, one end of the resonant circuit being connected to a first node and the other end of the resonant circuit being connected to a second node; and a controller configured to control the multiple switches in the selection circuit and the one or more switches in the resonant circuit to measure the impedance of a selected cell among the multiple cells or to perform charge equalization among the multiple cells or among the multiple modules.

[0016] The resonant circuit may include: a first inductor; and a first capacitor connected in series with the first inductor.

[0017] The resonant circuit may further include: a second inductor and an inductor connection switch connected in parallel with the first inductor; and a second capacitor and a capacitor connection switch connected in parallel with the first capacitor.

[0018] Here, the resonant frequency provided by the resonant circuit can vary depending on whether the inductor connection switch and the capacitor connection switch are turned on or off.

[0019] In addition, the battery control device may also include: a voltmeter that measures the voltage between the first node and the second node; and an ammeter that measures the current flowing through the resonant circuit.

[0020] Here, the controller can also be configured to: turn on the switch connected to the positive terminal of the cell whose impedance is to be measured and the switch connected to the negative terminal of the cell; and calculate the impedance of the cell based on the voltage obtained from the voltmeter and the current obtained from the ammeter.

[0021] In addition, the battery control device may also include a polarity reversal switch having one end connected to a first node and the other end connected to a second node.

[0022] Meanwhile, the controller can also be configured to: turn on the positive and negative connection switches of the first cell, thereby accumulating energy in the capacitor within the resonant circuit; and subsequently, turn off the positive and negative connection switches of the first cell, and turn on the positive and negative connection switches of the second cell, so that energy from the first cell is transferred to the second cell.

[0023] Here, the controller can also be configured such that if the first cell and the second cell are of odd number and even number in terms of their series connection structure, a polarity reversal switch is turned on to reverse the polarity of the capacitor in the resonant circuit before the positive and negative connection switches of the second cell are turned on; and subsequently, the positive and negative connection switches of the second cell are turned on, thereby transferring the energy stored in the capacitor to the second cell.

[0024] Additionally, the controller can be configured such that if both the first and second cells are odd-numbered cells or both are even-numbered cells in terms of their series connection structure, then after transferring the energy stored in the capacitor to the second cell, a polarity reversal switch is turned on to reverse the polarity of the capacitor in the resonant circuit.

[0025] Here, when performing cell-to-cell charge balancing from the first cell to the second cell, the controller controls the inductor connection switch and the capacitor connection switch to be turned off.

[0026] Meanwhile, the resonant circuit may include an inductor connected to the first node and a capacitor connected to the second node, and the resonant circuit may be arranged in each module.

[0027] The device may also include one or more resonant circuit connection switch units connected to the resonant circuit located within each module, and each resonant circuit connection switch unit may include a pair of resonant circuit connection switches connected to one end and the other end of a capacitor of the resonant circuit within each module.

[0028] The controller can be configured to perform charge balancing between the first module and the second module by: turning on the switch connecting the positive terminal of the first cell in the series-connected cells of the first module and the switch connecting the negative terminal of the last cell in the series-connected cells of the first module, and turning on one or more resonant circuit connection switching units in the battery pack, thereby accumulating energy in the capacitors of the multiple resonant circuits; and subsequently, turning off the connection switch of the first module, and turning on the switch connecting the positive terminal of the first cell in the series-connected cells of the second module and the switch connecting the negative terminal of the last cell in the series-connected cells of the second module.

[0029] Furthermore, the controller can be configured to turn on a switch connected to the positive terminal of the cell whose impedance is to be measured and a switch connected to the negative terminal of the cell whose impedance is to be measured; measure the current flowing through the resonant circuit and the voltage between the first node and the second node; and calculate the impedance of the target cell based on the measured current and voltage.

[0030] Here, the resonant frequency of the resonant circuit varies depending on the on / off state of one or more resonant circuit connected switching units.

[0031] According to another embodiment of this disclosure, a battery pack including multiple modules may include: a plurality of cells connected in series; a selection circuit including one or more switches connected to the positive terminal of each cell and one or more switches connected to the negative terminal of each cell; and a resonant circuit including one or more inductors and one or more capacitors, one end of the resonant circuit being connected to a first node and the other end of the resonant circuit being connected to a second node, and the battery pack may include a controller configured to control the plurality of switches in the selection circuit and the one or more switches in the resonant circuit to measure the impedance of a selected cell among the plurality of cells or to perform charge equalization among the plurality of cells or to perform charge equalization among the plurality of modules.

[0032] Beneficial effects

[0033] A battery control device according to an embodiment of the present disclosure enables both charge balancing in individual cells and battery impedance measurement.

[0034] The battery control device according to another embodiment of the present disclosure enables both charge balancing and battery impedance measurement within the module.

[0035] In addition, impedance can be measured in various resonant frequency environments, thus providing more accurate battery diagnostics. Attached Figure Description

[0036] Figure 1 An example of a battery structure to which embodiments of the present invention can be applied is illustrated.

[0037] Figure 2 A circuit diagram of a battery control device according to an embodiment of the present invention is shown.

[0038] Figure 3 The illustration shows current flowing in a resonant circuit according to an embodiment of the present invention.

[0039] Figure 4 This is an exemplary illustration of the path formed between a selected cell and a resonant circuit when measuring impedance using a battery control device according to an embodiment of the present invention.

[0040] Figure 5 The illustration shows a first example of an operational sequence for performing cell-to-cell balancing using a battery control device according to an embodiment of the present invention.

[0041] Figure 6 The illustration shows a second example of cell-to-cell balancing using a battery control device according to an embodiment of the present invention.

[0042] Figure 7 A circuit diagram of a battery control device according to another embodiment of the present invention is shown.

[0043] Figure 8a and Figure 8b An exemplary sequence of operations is illustrated for performing inter-module balancing using a battery control device according to an embodiment of the present invention.

[0044] 100: Battery pack

[0045] 200: BMS

[0046] 210: Controller

[0047] 220, 720: Selection circuit

[0048] 230, 730: Resonant circuit

[0049] 770: Resonant circuit connected to switching unit Detailed Implementation

[0050] This invention can be modified in various forms and has various embodiments, and specific embodiments thereof are shown by way of example in the accompanying drawings and will be described in detail below. However, it should be understood that the invention is not intended to be limited to the specific embodiments, but rather, the invention should cover all modifications, equivalents, and substitutions falling within the spirit and technical scope of the invention. Throughout the description of the accompanying drawings, the same reference numerals refer to the same elements.

[0051] It will be understood that although terms such as first, second, A, B, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element without departing from the scope of the invention, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes a combination of or any of a plurality of associated listed items.

[0052] It will be understood that when a component is described as "coupled" or "connected" to another component, it can be directly coupled or connected to the other component, or there may be intermediate components. Conversely, when a component is described as "directly coupled" or "directly connected" to another component, there are no intermediate components.

[0053] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprising,” “including,” “containing,” “covering,” and / or “having,” when used herein, specify the presence of stated features, integers, steps, operations, constituent elements, components, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, constituent elements, components, and / or combinations thereof.

[0054] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will be further understood that terms such as those defined in common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant field, and will not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0055] Some of the terms used in this article are defined as follows.

[0056] A battery cell is a basic unit used to store electricity, and a battery module may include multiple battery cells connected in series.

[0057] A battery pack is an assembly of multiple electrically connected battery cells and can be configured with multiple modules connected in series or in parallel.

[0058] In the following, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0059] Figure 1 An example of a battery structure to which embodiments of the present invention can be applied is illustrated.

[0060] exist Figure 1In this battery pack 100, multiple battery cells may be included. These cells can be connected in series to form modules, and the battery pack may include multiple modules. The most commonly used battery cell is a lithium-ion (Li-Ion) battery cell. The battery pack can be connected to a load via positive and negative terminals and perform charging / discharging operations. Each battery pack may be equipped with a battery management system (BMS).

[0061] The BMS 200 can monitor the current, voltage, and temperature of each battery pack under management, calculate the state of charge (SOC) based on the monitoring results, and control charging and discharging. Here, SOC expresses the current charge level of the battery as a percentage (%).

[0062] To perform these operations, the BMS 200 may include various components such as fuses, current sensing elements, thermistors, switches, and balancers. The BMS 200 typically includes a microcontroller unit (MCU) 201 or a battery monitoring integrated chip (BMIC) for interfacing with and controlling these components. The BMIC may be an IC-type component located within the BMS and capable of measuring information such as the voltage, temperature, and current of individual battery cells / modules. The BMS 200 may also include a memory 202 storing at least one command executed by the MCU and various data generated during BMS operation.

[0063] Additionally, the BMS can monitor individual battery cells, read their voltages, and transmit this information to other systems connected to the battery. For this purpose, the BMS may include a communication module (not shown) for communicating with other systems within the device, including the battery system. The BMS communication module can communicate with other systems within the device using a Controller Area Network (CAN). Here, components, modules, or systems within the BMS can be interconnected via a CAN bus.

[0064] The battery control device according to embodiments of the present invention described below can be incorporated into a group BMS and implemented as part of the group BMS.

[0065] Figure 2 A circuit diagram of a battery control device according to an embodiment of the present invention is shown.

[0066] The battery control device according to embodiments of the present invention can be applied to a battery structure in which the battery pack includes multiple modules, each module having multiple cells connected in series. For example, such as Figure 2 As illustrated, module 110 may have multiple units connected in series.

[0067] According to an embodiment of the present invention, a battery control device can control a battery pack comprising multiple modules, each module comprising multiple cells connected in series. The battery control device can be configured to include a controller 210, a selection circuit 220, and a resonant circuit 230. The controller 210 can control multiple switches in the selection circuit and one or more switches in the resonant circuit to measure the impedance of one of the multiple cells or to perform charge equalization among the multiple cells or among the multiple modules.

[0068] Figure 2 The embodiments described herein specifically illustrate a battery control device for measuring the impedance of one of a plurality of cells or performing cell balancing among a plurality of cells.

[0069] More specifically, in Figure 2 In this circuit, controller 210 can generate switching control signals for switches W1, W2, W3, W4, and W5 in selection circuit 220 and switches W7 and W8 in resonant circuit 230, and send the switching control signals to the corresponding circuits. Furthermore, controller 210 can receive voltage values ​​measured by voltmeter 280 and current values ​​measured by ammeter 290 to calculate the impedance value of the selected unit.

[0070] Furthermore, the selection circuit 220 may include one or more switches connected to the positive terminal of each individual cell and one or more switches connected to the negative terminal of each individual cell. For example, in Figure 2 In this circuit, selection circuit 220 may include five switches W1, W2, W3, W4, and W5 connected to the positive and negative terminals of four individual cells. The positive terminal of the first cell is connected to the first switch, and the negative terminal of the first cell is connected to the second switch. The second switch is also connected to the positive terminal of the second cell. The negative terminal of the second cell is connected to the third switch, and the third switch is simultaneously connected to the positive terminal of the third cell. In summary, the switches connected to the positive terminals of the multiple cells connected in series are alternately connected to the first node or the second node. In other words, the first switch connected to the positive terminal of the first cell and the third switch connected to the positive terminal of the third cell have one end connected to the first node, and the second switch connected to the positive terminal of the second cell and the fourth switch connected to the positive terminal of the fourth cell have one end connected to the second node. In other words, the switches connected to the negative terminals of the multiple cells connected in series can be described as being alternately connected to the second node or the first node.

[0071] Meanwhile, the switches W1, W2, W3, W4, and W5 included in the selection circuit 220 can be implemented using various switching elements, and according to one embodiment, the switches can be implemented using metal-oxide-semiconductor field-effect transistors (MOSFETs). Switches W1, W2, W3, W4, and W5 can be selectively turned on or off according to control signals from the controller 210.

[0072] Alternatively, the resonant circuit 230 may have one or more inductors and one or more capacitors connected in series by one or more switches, and one end of the resonant circuit 230 is connected to the first node, and the other end of the resonant circuit 230 is connected to the second node.

[0073] Here, the resonant circuit may include: a first inductor; a first capacitor connected in series with the first inductor; a second inductor and an inductor connection switch connected in parallel with the first inductor; and a second capacitor and a capacitor connection switch connected in parallel with the first capacitor.

[0074] More specifically, see reference Figure 2 The resonant circuit 230 may include an inductor (L1, L2) and a capacitor (C1, C2) connected in series.

[0075] The inductor section (L1, L2) can be formed by a first inductor (L1) and a second inductor (L2) connected in parallel. By turning on the inductor connection switch W7, the second inductor (L2) can form part of the inductor section together with the first inductor L1. Conversely, when the inductor connection switch W7 is turned off, the second inductor L2 is excluded from the inductor section. In other words, the inductance value of the inductor section can be adjusted according to the on / off control of the inductor connection switch.

[0076] The capacitor section (C1, C2) can be configured with a first capacitor C1 and a second capacitor C2 connected in parallel. By turning on the capacitor connection switch W8, the second capacitor C2 can form part of the capacitor section together with the first capacitor C1. Conversely, when the capacitor connection switch W8 is turned off, the second capacitor C2 can be excluded from the capacitor section. In other words, the capacitance value of the capacitor section can be adjusted according to the on / off control of the capacitor connection switch.

[0077] In other words, the resonant frequency provided by the resonant circuit 230 can vary depending on the on / off state of the inductor connection switch W7 and the capacitor connection switch W8.

[0078] Furthermore, the battery control device according to this embodiment may also include a voltmeter 280 for measuring the voltage between the first node and the second node, and an ammeter 290 for measuring the current flowing through the resonant circuit. The controller can turn on a switch connected to the positive terminal of the cell whose impedance is to be measured and a switch connected to the negative terminal of the cell, and calculate the impedance of the corresponding cell based on the voltage obtained from the voltmeter and the current obtained from the ammeter.

[0079] Additionally, when through methods including such Figure 2 When configuring the battery pack using the multiple modules shown in the diagram, according to Figure 2 The controller 210 in the embodiment can be implemented by placing it in each module. Alternatively, the battery pack can be implemented such that only one controller 210 is placed in the battery pack to control the circuitry within each module.

[0080] Figure 3 The illustration shows the current flowing in a resonant circuit and the individual cell voltage according to an embodiment of the present invention.

[0081] Figure 3 The upper curve in the graph represents the... Figure 2 The resonant current flows in the resonant circuit 230. The resonant current is an alternating current (AC) flowing through the path connecting the cell selected by the controller, the first inductor, and the first capacitor. In other words, the resonant current can be the current flowing through the selected cell.

[0082] also, Figure 3 The lower curve in the middle represents Figure 2 The measured voltage is between the first and second nodes in the circuit. If a single cell is selected by controlling a switch in the selection circuit, either the first or second node can be connected to the positive terminal of the single cell, and the other node can be connected to the negative terminal. Therefore, the voltage between the first and second nodes is equal to the voltage of the corresponding single cell.

[0083] Therefore, the controller can calculate the impedance of the selected cell based on the amplitude and phase difference of the AC components of the measured current and voltage.

[0084] Figure 4 This is an exemplary illustration of the path formed between a selected cell and a resonant circuit when measuring impedance using a battery control device according to an embodiment of the present invention.

[0085] Figure 4 The diagram illustrates the current generated when the fourth switch (W4) and the fifth switch (W5) are turned on to measure the impedance of the fourth of the four cells in the module. If both the inductor-connecting switch W7 and the capacitor-connecting switch W8 in the resonant circuit are turned off, the current flows as follows... Figure 4 As shown in the diagram.

[0086] Meanwhile, the resonant frequency provided by the resonant circuit 230 varies depending on the on / off state of the inductor connection switch W7 and the capacitor connection switch W8. For example... Figure 4 As illustrated, the inductor connection switch W7 and the capacitor connection switch W8 have four possible on / off scenarios. Therefore, according to... Figure 4The resonant circuit of this embodiment can provide a total of four resonant frequencies. Therefore, the controller can adjust the resonant frequency by changing the connection state of the inductor connection switch W7 and the capacitor connection switch W8, and can measure the impedance at different frequencies.

[0087] return Figure 2 The controller 210 can control multiple switches in the selection circuit and one or more switches in the resonant circuit to perform charge balancing among multiple cells. For this purpose, the battery control device according to an embodiment of the invention may further include a polarity reversal switch 250, having one end connected to a first node and another end connected to a second node. Here, the polarity reversal switch 250 is a switch for changing the polarity of the resonant capacitor C1.

[0088] More specifically, the controller can turn on the positive and negative connection switches of the first cell to accumulate energy in the capacitor within the resonant circuit. Then, the controller can turn off the positive and negative connection switches of the first cell and turn on the positive and negative connection switches of the second cell, thereby performing charge balance between the first and second cells.

[0089] According to one embodiment, when the first and second cells are of odd number and even number in terms of the order of their cell connection structure, a polarity reversal switch is turned on before the positive and negative connection switches of the second cell are turned on, in order to reverse the polarity of the capacitor in the resonant circuit. Then the positive and negative connection switches of the second cell are turned on to control the connection of the energy stored in the capacitor, thereby allowing the energy stored in the capacitor to be transferred to the second cell.

[0090] According to another embodiment, when both the first and second cells are odd-numbered cells or both are even-numbered cells in terms of the order of their cell connection structure, after the energy stored in the capacitor is transferred to the second cell, a polarity reversal switch can be turned on to reverse the polarity of the capacitor in the resonant circuit.

[0091] Figure 5 The illustration shows a first example of an operation sequence for performing cell-to-cell balancing according to a battery control device used in an embodiment of the present invention.

[0092] Figure 5 The example illustration shows the sequence of monomer-to-monomer balancing operations as energy is transferred from the first monomer to the fourth monomer.

[0093] More specifically, the controller connects the positive and negative terminals of the first cell to accumulate energy in capacitor C1 within the resonant circuit. Figure 5Step 1). Then, the controller shuts off the positive and negative connection switches of the first cell and connects the positive and negative connection switches of the fourth cell. Figure 5 Step 3), thereby performing monomer-to-monomer balancing from the first monomer to the fourth monomer.

[0094] Here, since the first unit is an odd-numbered unit and the fourth unit is an even-numbered unit according to the series connection structure of the units, the polarity reversal switch (W6) is turned on before the positive and negative connection switches of the fourth unit are turned on to reverse the polarity of the capacitor C1 in the resonant circuit. Figure 5 Step 2), and then control the positive and negative connection switches of the fourth cell to be turned on, so that the energy stored in the capacitor can be transferred to the fourth cell ( Figure 5 (Step 3 in the circuit). Here, when energy is accumulated in capacitor C1 in the resonant circuit, the voltage of the first node becomes higher than the voltage of the second node, and in order to transfer energy to the fourth cell, the voltage of the second node must be higher than the voltage of the first node. Therefore, before transferring energy to the fourth cell, the polarity of the resonant capacitor is controlled to reverse by a polarity reversing switch.

[0095] The controller can then repeat steps 1 through 3 above. The number of repetitions can be determined based on factors such as the voltage difference between the cells requiring energy transfer and the cumulative capacitance of the resonant capacitor.

[0096] Simultaneously, while performing inter-unit balancing, the controller can control the switching of inductor connection switch W7 and capacitor connection switch W8 within the resonant circuit to be turned on or off. Depending on the on / off state of inductor connection switch W7 and capacitor connection switch W8, the impedance of the resonant circuit can be changed, thereby controlling the balancing current. While increasing the balancing current has the advantage of faster balancing, it also has the disadvantage of increasing the energy consumed by the circuit. Therefore, the impedance can be appropriately adjusted by controlling the inductor connection switches and capacitor connection switches according to the situation.

[0097] Figure 6 The illustration shows a second example of cell-to-cell balancing using a battery control device according to an embodiment of the present invention.

[0098] Figure 6 The example illustration shows the sequence of monomer-to-monomer balance operations when energy is transferred from the second monomer to the fourth monomer.

[0099] More specifically, the controller can connect the positive and negative terminals of the second cell to accumulate energy in the capacitor within the resonant circuit. Figure 6Step 1). Afterwards, the controller can turn off the positive and negative connection switches of the second cell and turn on the positive and negative connection switches of the fourth cell. Figure 6 Step 2), which allows for charge balance between the second and fourth monomers.

[0100] Furthermore, since both the second and fourth cells are even-numbered cells in terms of their series connection sequence, the polarity reversal switch (W6) is turned on after the energy stored in capacitor C1 is transferred to the fourth cell. Figure 6 Step 3) Reverses the polarity of capacitor C1 in the resonant circuit. In this embodiment, the process of reversing the polarity of the resonant capacitor by using a polarity reversal switch is to transfer energy more efficiently by reversing the polarity of the resonant capacitor that has accumulated energy. More specifically, the magnitude of the resonant current is proportional to the difference between the individual cell voltage and the initial voltage of the resonant capacitor. If charging and discharging are repeated in the same direction, the voltage of the resonant capacitor converges to the same level as the individual cell voltage, which leads to a problem where the magnitude of the resonant current continues to decrease. In this embodiment, this problem can be solved by turning on the polarity reversal switch to reverse the polarity of the resonant capacitor.

[0101] The controller can then repeat steps 1 through 3 above. The number of repetitions can be determined based on factors such as the voltage difference between the cells requiring energy transfer and the cumulative capacitance of the resonant capacitor.

[0102] Simultaneously, while performing inter-unit balancing, the controller can control the inductor connection switch W7 and capacitor connection switch W8 within the resonant circuit to be switched on or off. The impedance of the resonant circuit can be changed depending on the on / off state of the inductor connection switch W7 and capacitor connection switch W8, thereby controlling the balancing current. While increasing the balancing current has the advantage of achieving balance more quickly, it also has the disadvantage of increasing the energy consumed in the circuit. Therefore, the impedance can be appropriately adjusted and used by controlling the inductor connection switch and capacitor connection switch according to the situation.

[0103] Figure 7 A circuit diagram of a battery control device according to another embodiment of the present invention is shown.

[0104] The battery control device according to an embodiment of the present invention can be applied to a battery structure in which the battery pack includes multiple modules and multiple cells are connected in series within a single module. Here, the multiple modules (module 1, module 2, and module 3) within the same group can be implemented in a series connection configuration, such as... Figure 7 As shown in the diagram.

[0105] According to an embodiment of the present invention, a battery control device can control a battery pack including module 110, which includes a plurality of cells connected in series. The battery control device can be configured to include a controller (not shown), a selection circuit 720, and a resonant circuit 730. The controller can control a plurality of switches in the selection circuit and one or more switches in the resonant circuit to measure the impedance of one of the plurality of cells or to perform charge balancing among the plurality of cells or among the plurality of modules.

[0106] Figure 7 The embodiments specifically describe a battery control device that measures the impedance of one of a plurality of cells or performs charge balancing among a plurality of modules.

[0107] exist Figure 7 In the example, the battery pack includes multiple modules, each module having five cells connected in series.

[0108] More specifically, the selection circuit 720 includes one or more switches connected to the positive terminal of each cell and one or more switches connected to the negative terminal of each cell. For example, Figure 7 The selection circuit 720 of module 1 includes six switches (W9, W10, W11, W12, W13, and W33) connected to the positive and negative terminals of the five individual units. Similar to... Figure 2 According to the embodiments, Figure 7 The selection circuit 720 of the embodiment has a switch connected to the positive terminal of each cell that is alternately connected to the first node or the second node. In other words, the other terminal of the switch connected to the positive terminal of the first cell, the switch connected to the positive terminal of the third cell, and the switch connected to the positive terminal of the fifth cell are connected to the second node, and the other terminal of the switch connected to the positive terminal of the second cell and the switch connected to the positive terminal of the fourth cell are connected to the first node.

[0109] Meanwhile, the switches W9, W10, W11, W12, W13, and W33 included in the selection circuit 720 can be implemented using various switching elements, and according to one embodiment, the switches can be implemented using MOSFETs. Switches W9, W10, W11, W12, W13, and W33 can be selectively turned on or off according to control signals from a controller (not shown).

[0110] Additionally, resonant circuits 730-1, 730-2, and 730-3 are arranged for each module, and in this embodiment, the resonant circuits may include an inductor connected to the first node and a capacitor connected to the second node. The battery control device may also include polarity reversing switches W14, W21, and W31 located between the contact point of the first node and the inductor and the contact point of the second node and the capacitor. Here, the resonant circuits 730-1, 730-2, and 730-3 and the polarity reversing switches can perform operations related to… Figure 2 The resonant circuit and polarity reversing switch included in the illustrated embodiment serve the same purpose. In this embodiment, the polarity reversing switch is used to transfer energy more efficiently by reversing the polarity of the resonant capacitor that has accumulated energy. More specifically, the magnitude of the resonant current is proportional to the difference between the individual cell voltage and the initial voltage of the resonant capacitor. However, if charging and discharging are repeated in the same direction, the voltage of the resonant capacitor converges to the same level as the individual cell voltage, resulting in a continuous decrease in the magnitude of the resonant current. In this embodiment, this problem can be solved by turning on the polarity reversing switch to reverse the polarity of the resonant capacitor.

[0111] Additionally, the battery control device may include one or more resonant circuit connection switch units 770-1 and 770-2 that connect the resonant circuit of a corresponding module to the resonant circuit of another adjacent module. Each resonant circuit connection switch unit may include a pair of resonant circuit connection switches (W15 and W30; W23 and W24) connected to one end and the other end of a capacitor of the resonant circuit within each module. The number of resonant circuit connection switch units may be set to (number of modules included in the battery pack - 1).

[0112] exist Figure 7 In some embodiments, for example, the resonant circuit 730-1 of module 1 and the resonant circuit 730-2 of module 2 can be connected by turning on the first resonant circuit and then connecting to the switching unit 770-1. Alternatively, the resonant circuit 730-1 of module 1 and the resonant circuit 730-3 of module 3 can be connected by turning on the first resonant circuit and then connecting to the switching unit 770-1, and then connecting the second resonant circuit and then connecting to the switching unit 770-2.

[0113] The controller of the battery control device can turn on the switch connected to the positive terminal of the cell whose impedance is to be measured and the switch connected to the negative terminal, measure the current flowing through the resonant circuit and the voltage between the first node and the second node, and calculate the impedance of the target cell based on the measured current and voltage. Here, the controller can set different resonant frequencies by controlling the on / off state of one or more resonant circuit connection switching units. Therefore, impedance can be measured for various resonant frequencies.

[0114] Furthermore, the battery control device according to an embodiment of the present invention may further include a voltmeter (not shown) for measuring the voltage between the first node and the second node, and an ammeter (not shown) for measuring the current flowing through the resonant circuit. The positions of the voltmeter and the ammeter can be determined relative to... Figure 2 The same location is shown in the embodiment illustrated in the figure.

[0115] Therefore, the controller can turn on the switch connected to the positive terminal of the battery undergoing impedance measurement and the switch connected to the negative terminal, and calculate the battery impedance based on the voltage obtained from the voltmeter and the current obtained from the ammeter.

[0116] In addition, the battery control device can use, for example Figure 7 The circuit shown in the figure performs charge balancing between the first module and the second module.

[0117] More specifically, the battery control device can turn on the switch connecting the positive terminal of the first cell in the series-connected cells in the first module and the switch connecting the negative terminal of the last cell in the series-connected cells, and turn on one or more resonant circuit connection switching units in the battery pack, thereby accumulating energy in the capacitors in the multiple resonant circuits.

[0118] Then, the battery control device can turn off the connection switch of the first module and turn on the switch of the positive terminal of the first cell connected in series in the second module and the switch of the negative terminal of the last cell connected in series, thereby transferring energy from the first module to the second module.

[0119] At the same time, such as Figure 7 As illustrated, when the battery pack is configured by including multiple modules, a single controller (not shown) can be located within the battery pack to control the circuitry within each module.

[0120] Here, the battery pack may include multiple modules, each module including: multiple cells connected in series; a selection circuit including one or more switches connected to the positive terminal of each cell and one or more switches connected to the negative terminal of each cell; and a resonant circuit including one or more inductors and one or more capacitors, one end of the resonant circuit being connected to a first node and the other end of the resonant circuit being connected to a second node.

[0121] Here, the battery pack may include a controller configured to control a plurality of switches in a selection circuit and one or more switches in a resonant circuit to measure the impedance of a selected cell among a plurality of cells or to perform charge balancing among a plurality of cells or to perform charge balancing among a plurality of modules.

[0122] Figure 8a and Figure 8b An exemplary sequence of operations is illustrated for performing inter-module balancing using a battery control device according to an embodiment of the present invention.

[0123] Figure 8a and Figure 8b The diagram illustrates the gradual current flow during the balancing operation between modules 1 and 3 as energy is transferred from module 1 to module 3.

[0124] Figure 8a The diagram illustrates the current flow when switches 33 and 13 of module 1 are turned on, and multiple switches (W15, W30, W23, and W24) within the first resonant circuit connected to the switching unit and the second resonant circuit connected to the switching unit are turned on, thereby storing energy in multiple resonant capacitors (C3, C4, and C5) within the multiple modules. Figure 8b The diagram shows that switches 33 and 13 are turned off, and switches 32 and 29 of module 3 are turned on, and the energy stored in multiple resonant capacitors (C3, C4, C5) is transferred to module 3.

[0125] At the same time, as with Figure 8a and Figure 8b In the illustrated example of a different scenario, even when energy is to be transferred from module 1 to module 2, both the first resonant circuit connected to the switching units (W15, W30) and the second resonant circuit connected to the switching units (W23, W24) can be turned on to store energy in the three resonant capacitors (C3, C4, C5), and then the switches of module 2 (W20, W22) can be turned on to transfer the accumulated energy to module 2. This method allows the resonant capacitors to be set as large as possible, thereby increasing the resonant current and achieving rapid balancing.

[0126] The operation of the method according to embodiments of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices in which computer systems store data readable by the computer. Furthermore, the computer-readable recording medium can be distributed across network-connected computer systems to store and execute the computer-readable program or code in a distributed manner.

[0127] Furthermore, computer-readable recording media can include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory, and can include, for example, various types of servers located on a network. Program instructions can include not only machine language code, such as machine language code created by a compiler, but also high-level language code that can be executed by a computer using an interpreter.

[0128] Although some aspects of the invention have been described in the context of apparatus, they may also refer to, according to the description of the corresponding method, a block or apparatus corresponding to a method step or feature of a method step. Similarly, aspects described in the context of a method may also refer to features of a corresponding block or item or a corresponding apparatus. Some or all of the method steps may be performed by (or using) hardware devices, such as, for example, microprocessors, programmable computers, or electronic circuits. In some embodiments, one or more of the most important method steps may be performed by such apparatus.

[0129] The present invention has been described above with reference to exemplary embodiments thereof; however, those skilled in the art will understand that various corrections and modifications may be made to the invention within the scope of the appended claims without departing from the spirit and scope of the invention as described therein.

Claims

1. A device for controlling a battery pack, the battery pack comprising a plurality of modules, each module comprising a plurality of cells connected in series, the device comprising: The selection circuit includes one or more switches connected to the positive terminal of each cell and one or more switches connected to the negative terminal of each cell. A resonant circuit, comprising one or more inductors and one or more capacitors, wherein one end of the resonant circuit is connected to a first node and the other end of the resonant circuit is connected to a second node; as well as A controller configured to control a plurality of switches in the selection circuit and one or more switches in the resonant circuit to measure the impedance of a selected cell among the plurality of cells or to perform charge balancing among the plurality of cells or among the plurality of modules.

2. The apparatus according to claim 1, wherein, The resonant circuit includes: First inductor; and The first capacitor is connected in series with the first inductor.

3. The apparatus according to claim 2, wherein, The resonant circuit further includes: A second inductor connected in parallel with the first inductor and an inductor connection switch; and A second capacitor and a capacitor connection switch are connected in parallel with the first capacitor.

4. The apparatus according to claim 3, wherein, The resonant frequency provided by the resonant circuit varies depending on whether the inductor connection switch and the capacitor connection switch are turned on or off.

5. The apparatus according to claim 1, further comprising: A voltmeter that measures the voltage between the first node and the second node; as well as An ammeter that measures the current flowing through the resonant circuit.

6. The apparatus according to claim 5, wherein, The controller is also configured to: Turn on the switch connected to the positive terminal of the cell whose impedance is to be measured and the switch connected to the negative terminal of the cell; and The impedance of the cell is calculated based on the voltage obtained from the voltmeter and the current obtained from the ammeter.

7. The apparatus according to claim 1, further comprising: A polarity reversing switch having one end connected to the first node and the other end connected to the second node.

8. The apparatus according to claim 7, wherein, The controller is also configured to: By connecting the positive and negative terminals of the first cell, energy is accumulated in the capacitor within the resonant circuit; and Subsequently, the positive and negative connection switches of the first cell are turned off, and the positive and negative connection switches of the second cell are turned on, so that the energy from the first cell is transferred to the second cell.

9. The apparatus according to claim 8, wherein, The controller is also configured to: If, in terms of the series connection structure of the first and second monomers, one is an odd-numbered monomer and the other is an even-numbered monomer, Before the positive and negative connection switches of the second cell are turned on, the polarity reversal switch is turned on to reverse the polarity of the capacitor in the resonant circuit. and Subsequently, the positive and negative connection switches of the second cell are turned on, thereby transferring the energy stored in the capacitor to the second cell.

10. The apparatus according to claim 8, wherein, The controller is also configured to: If both the first monomer and the second monomer are odd-numbered monomers or both are even-numbered monomers in terms of their tandem connection structure, After the energy stored in the capacitor is transferred to the second cell, the polarity reversal switch is turned on to reverse the polarity of the capacitor in the resonant circuit.

11. The apparatus according to claim 3, wherein, When performing a single-to-single charge balancing operation from the first single cell to the second single cell, the controller controls the inductor connection switch and the capacitor connection switch to be turned off.

12. The apparatus according to claim 1, wherein, The resonant circuit includes: The inductor connected to the first node; and The capacitor connected to the second node, and The resonant circuit is arranged in each module.

13. The apparatus of claim 12, further comprising: One or more resonant circuits are connected to a switching unit, and the one or more resonant circuits connected to the switching unit are connected to the resonant circuit located within each module. Each resonant circuit connection switch unit includes a pair of resonant circuit connection switches connected to one end and the other end of a capacitor connected to the resonant circuit within each module.

14. The apparatus according to claim 13, wherein, The controller is configured to perform charge balancing between the first module and the second module by: The switch connecting the positive terminal of the first cell in the series-connected cells in the first module and the switch connecting the negative terminal of the last cell in the series-connected cells are turned on, and the one or more resonant circuit connection switch units in the battery pack are turned on, thereby accumulating energy in the capacitors in the multiple resonant circuits. and Subsequently, the connection switch of the first module is turned off, and the switch connecting the positive terminal of the first cell in the series-connected cells of the second module and the switch connecting the negative terminal of the last cell in the series-connected cells of the second module are turned on.

15. The apparatus according to claim 13, wherein, The controller is configured to: Turn on the switch connected to the positive terminal of the single cell whose impedance is to be measured and the switch connected to the negative terminal of the single cell whose impedance is to be measured; Measure the current flowing through the resonant circuit and the voltage between the first node and the second node; and The impedance of the target cell is calculated based on the measured current and voltage.

16. The apparatus according to claim 15, wherein, The resonant frequency of the resonant circuit varies depending on the on / off state of the one or more resonant circuit connected switching units.

17. A battery pack comprising multiple modules, each module comprising: Multiple units connected in series; The selection circuit includes one or more switches connected to the positive terminal of each cell and one or more switches connected to the negative terminal of each cell. as well as A resonant circuit, comprising one or more inductors and one or more capacitors, wherein one end of the resonant circuit is connected to a first node and the other end of the resonant circuit is connected to a second node. The battery pack includes: A controller configured to control a plurality of switches in the selection circuit and one or more switches in the resonant circuit to measure the impedance of a selected cell among the plurality of cells or to perform charge balancing among the plurality of cells or to perform charge balancing among the plurality of modules.

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