Power supply circuit for a battery management circuit

Abstract

Embodiments of the present disclosure relate to a power supply circuit for a battery management circuit. The battery management circuit can be configured to monitor a plurality of battery cells. The battery management circuit can include a battery monitoring circuit and a power supply circuit configured to power the battery monitoring circuit based on the plurality of battery cells. The power supply circuit can include a DC / DC power converter and a regulator, and wherein the DC / DC power converter is configurable based on a number of monitored battery cells of the plurality of battery cells.

Description

Technical Field

[0001] This disclosure relates to battery management circuitry, and more specifically, to a power supply circuitry configured to supply power to battery monitoring circuitry in a battery management system (BMS). Background Technology

[0002] Battery-powered devices, such as electric vehicles, typically include a number of battery cells connected in series to form a battery system for the device. For such battery systems, a battery management system (BMS) is typically used for battery cell monitoring, thermal monitoring, block balancing of different groups of battery cells, or other battery management functions.

[0003] A Battery Management System (BMS) typically uses several different battery monitoring circuits to monitor all battery cells in a battery-powered device. For example, each battery monitoring circuit can monitor a subgroup of battery cells in the battery system that supplies power to the battery-powered device. The battery monitoring circuits can use different analog-to-digital converters or multiplexing techniques to monitor several cells. However, the number of channels in each battery monitoring circuit may be limited, and therefore several battery monitoring circuits may be needed within a BMS to monitor all cells in the battery system.

[0004] For example, an electric vehicle may include a battery system with one hundred or more battery cells connected in series, but the battery monitoring circuitry may include a more limited number of channels, such as only twelve. In this case, nine battery monitoring circuits might be needed within the BMS to monitor all one hundred cells of the battery system. As a result, in some cases, some battery monitoring circuits may monitor fewer battery cells than the number of available channels in the battery monitoring circuitry, which could lead to challenges in power supply adaptation for the supply current used to power the battery monitoring circuitry. Summary of the Invention

[0005] Generally, this disclosure relates to techniques and circuits for controlling the power supply (e.g., current or voltage) to a battery monitoring circuit that monitors battery cells. In particular, this disclosure describes a circuit in which a DC / DC power converter is implemented as part of a power supply circuit for monitoring battery cells. The battery cells themselves can provide input power to the power supply circuit, and the DC / DC power converter can be configured to account for the number of battery cells being monitored. Furthermore, the DC / DC power converter can also be configured to account for other factors, such as factors defining a minimum number of battery cells being monitored within a battery management system (BMS), and / or factors accounting for manufacturing variations during integrated circuit production. Thus, the power supply circuit can be adaptive or configurable to facilitate balanced power supply to the battery monitoring circuit under different conditions that may have different numbers of battery cells.

[0006] In one example, this disclosure describes a battery management circuit configured to monitor a plurality of battery cells. The battery management circuit may include a battery monitoring circuit and a power supply circuit configured to power the battery monitoring circuit based on the plurality of battery cells. Furthermore, according to this disclosure, the power supply circuit may include a DC / DC power converter and a regulator, wherein the DC / DC power converter is configurable based on the number of monitored battery cells among the plurality of battery cells.

[0007] In another example, this disclosure describes a method that includes powering a battery monitoring circuit using a power supply circuit and a plurality of battery cells of a battery system, wherein the power supply circuit includes a DC / DC power converter and a regulator, and the DC / DC power converter is controlled according to configurable parameters, the configurable parameters being configurable based on the number of monitored battery cells among the plurality of battery cells.

[0008] In another example, this disclosure describes a battery management system (BMS) configured to monitor a plurality of battery cells arranged in series. The BMS may include a first battery monitoring circuit and a second battery monitoring circuit. The first battery monitoring circuit is configured to monitor a first subgroup of the plurality of battery cells, and the second battery monitoring circuit is configured to monitor a second subgroup of the plurality of battery cells, wherein the second subgroup differs from the first subgroup and includes a different number of battery cells than the first subgroup. The BMS may also include a first power supply circuit and a second power supply circuit. The first power supply circuit is configured to power the first battery monitoring circuit based on the first subgroup of the plurality of battery cells, and the second power supply circuit is configured to power the second battery monitoring circuit based on the second subgroup of the plurality of battery cells, wherein the first and second power supply circuits are configured to define substantially similar power supplies to the first and second battery monitoring circuits. The first and second power supply circuits may include structurally similar DC / DC power converters, but the DC / DC power converters of the first and second power supply circuits may be configured with different so-called K-factors. The K-factor can adjust the DC / DC power converters for different numbers of battery cells in the first and second subgroups. Furthermore, in some examples, the K-factor can also indicate the minimum number of battery cells being monitored within the BMS. Additionally, in some examples, the K-factor can also indicate manufacturing variations during integrated circuit production.

[0009] Details of these and other examples are set forth in the accompanying drawings and the following description. Other features, objects, and advantages will be apparent from the description and the accompanying drawings. Attached Figure Description

[0010] Figure 1This is a block diagram showing a battery cell and a battery monitoring system (BMS) including power supply circuitry and battery monitoring circuitry.

[0011] Figure 2 This is a block diagram showing a battery cell and a BMS including several battery monitoring circuits and several power supply circuits.

[0012] Figure 3 This is a block diagram showing an example power supply circuit that can be coupled to a battery cell and a load.

[0013] Figure 4 This is a block diagram illustrating examples of several power supply circuits that can be coupled to different groups of battery cells and different loads.

[0014] Figure 5 and Figure 6 This is a block diagram showing an example power supply circuit that can be coupled to a battery cell and a load.

[0015] Figure 7 It is a flowchart consistent with the technology of this disclosure. Detailed Implementation

[0016] This disclosure relates to techniques for controlling the supply (e.g., current or voltage) to a battery monitoring circuit for monitoring battery cells. In particular, this disclosure describes a circuit in which a DC / DC power converter is implemented as part of a power supply circuit for monitoring battery cells. The battery cells themselves can provide input power to the power supply circuit, and the DC / DC power converter of the power supply circuit can be configured to account for the number of battery cells being monitored. Furthermore, the DC / DC power converter can also be configured to account for other factors, such as a minimum number of battery cells being monitored defined within a battery management system (BMS), and / or factors accounting for manufacturing variations during the integrated circuit manufacturing process.

[0017] In some examples, this disclosure contemplates a power supply circuit that includes a DC / DC power converter comprising a customer-configurable k-factor defining the ratio between an input current or voltage and an output current or voltage. In addition to the DC / DC power converter, the power supply circuit may also include a regulator, such as a linear regulator (LDO), to achieve lower power consumption and better power supply adaptation across the entire battery management system (BMS).

[0018] For any given application of the power supply circuit, the k-factor of the DC / DC power converter can be adjusted based on the number of battery cells being monitored. For example, the k-factor can differ depending on whether the power supply circuit is powering a battery monitoring circuit monitoring eleven battery cells or eight battery cells. Furthermore, the k-factor of the DC / DC power converter can be configured to account for other circuit factors, such as factors defining the minimum number of battery cells used within a larger BMS, and / or factors accounting for manufacturing variations during the integrated circuit production process. This allows for better adjustment of the supply current or supply voltage for different battery monitoring scenarios, such as different numbers of battery cells being monitored.

[0019] For example, an electric vehicle may include a battery system with one hundred or more battery cells connected in series, but the battery monitoring circuitry may include a more limited number of channels, such as only twelve. In this case, nine battery monitoring circuits may be needed within the BMS to monitor all one hundred cells of the battery system. The circuitry and techniques disclosed herein can help improve the power supply to the battery monitoring circuitry in these situations, illustrating the different numbers of channels used by different battery monitoring circuits.

[0020] Figure 1 This is a block diagram illustrating a battery cell and a battery management system (BMS), which includes a power supply circuit 102 and a battery monitoring circuit 106 for monitoring the battery cell 100. The battery cell 100 may include a group of battery cells connected in series. To monitor the battery cells, the power supply circuit 102 uses power from the battery cells to power a cell selection component 104 and the battery monitoring circuit. The cell selection component 104 individually connects each cell within the battery cell 100 to the battery monitoring circuit 106, allowing the battery monitoring circuit 106 to monitor each cell, such as by measuring or tracking the potential energy stored in each cell. For example, the cell selection component 104 may include circuit elements forming a multiplexer or other type of selection circuit that can individually connect each cell within the battery cell 100 to the battery monitoring circuit 106.

[0021] According to this disclosure, the power supply circuit 102 can be configured to supply (at least partially) a current or voltage to the battery monitoring circuit 106 based on the number of battery cells within the battery cell 100. More specifically, the power supply circuit 102 may include a DC / DC power converter and a regulator, such as an LDO regulator. The DC / DC power converter of the power supply circuit 102 is configurable based on the number of monitored battery cells among a plurality of battery cells, for example, the number of cells within the battery cell 100. Thus, for example, the DC / DC power converter can be configured differently in the case where the battery cell 100 includes twelve battery cells compared to the case where the battery cell 100 includes nine battery cells.

[0022] According to this disclosure, the DC / DC power converter within the power supply circuit 102 can be configured to define an input-to-output ratio of the DC / DC power converter, which can be an input-to-output current ratio or an input-to-output voltage ratio. This ratio can be defined by a configurable parameter based on the number of monitored battery cells. Therefore, the customer can adjust the configurable parameter to accommodate different numbers of monitored battery cells. In some cases, the configurable parameter can be based on the number of battery cells being monitored, and also on the minimum number of battery cells being monitored and powered by other circuits within a larger BMS.

[0023] In some cases, the DC / DC power converter is configurable based on multiple factors. For example, the DC / DC power converter is configurable based on a first K-factor, which is defined based on the number of monitored battery cells and the minimum number of battery cells being monitored within a given BMS. Furthermore, the DC / DC power converter can also be configurable based on a second K-factor defined during the manufacturing process of the battery management circuitry to adjust the DC / DC power converter. The first K-factor can be defined at least in part by the customer based on usage conditions, and the second K-factor can be defined by the integrated circuit manufacturer to help compensate for changes in the operation of the battery management circuitry caused by thermal variations or other manufacturing factors or changes. The customer can select the actual number of monitored battery cells for a given usage condition, and the customer can select the minimum number of battery cells being monitored within the BMS. Thus, the user can configure the power supply circuit 102 by defining the first K-factor of the DC / DC power converter within the power supply circuit 102 based on the number of monitored battery cells for a given usage condition and the minimum number of battery cells in any given cell block within the BMS.

[0024] In addition to improving power supply, in some cases, the power supply circuit 102 can also be configured to excite multiple cells (at one or more desired frequencies) while the battery monitoring circuit monitors these cells. This helps ensure accurate cell monitoring and responsiveness and can aid in impedance measurements. Furthermore, in some examples, the power supply circuit 102 can also be configured to perform charge balancing of the battery cell 100 relative to other cell groups or blocks; for example, drawing more or less charge from the battery cell 100 to balance the charge relative to one or more other cell groups may be desirable. For example, using the power supply circuit 102 to perform charge balancing of the battery cell 100 can reduce or eliminate the charge balancing function performed by the battery monitoring circuit 106 or another circuit.

[0025] As mentioned above, in many cases, the number of battery cells in a system can be greater than the number of monitoring channels of the battery monitoring circuit. Therefore, in many cases, several battery monitoring circuits can be used within a larger BMS. The power supply circuit of this disclosure can be used for each battery monitoring circuit within a larger BMS, in which case each battery monitoring circuit can monitor different subgroups of battery cells within the larger battery system. The K-factor described herein allows the power supply circuit to be adjusted based on the number of cells associated with the power supply circuit and based on the minimum number of cells within any cell block of the BMS.

[0026] Figure 2 This is a block diagram illustrating a battery cell and a BMS including several battery monitoring circuits and several power supply circuits. Specifically, the battery cell 200 may include a first subgroup 201A of battery cells, a second subgroup 201B of battery cells, and an Mth subgroup 201C of battery cells. Figure 2 In this context, "M" can represent any positive integer, such that unit 200 can include any number of units that can be divided into any number of different subgroups. Different subgroups can have different numbers of battery units, although one or more subgroups can have the same or similar number of battery units. For each subgroup of battery units 201A, 201B, 201C, unit selection components 204A, 204B, 204C can individually connect each unit within the corresponding subgroup to the corresponding battery monitoring circuits 206A, 206B, 206C.

[0027] The technology disclosed herein can improve the power supply to the battery monitoring circuits 206A, 206B, 206C by implementing power supply circuits 202A, 202B, 202C configured for the different monitored subgroups 201A, 201B, 201C. Figure 2In this configuration, battery monitoring circuits 206A, 206B, and 206C are collectively referred to as battery monitoring circuit 206; power supply circuits 202A, 202B, and 202C are collectively referred to as power supply circuit 202; cell selection components 204A, 204B, and 204C are collectively referred to as cell selection component 204; and different subgroups 201A, 201B, and 201C are collectively referred to as subgroup 201. Power supply circuit 202, cell selection component 204, and battery monitoring circuit 206 can form a larger BMS for monitoring all battery cells 200.

[0028] Battery cell 200 can represent multiple battery cells arranged in series. Power supply circuit 202, cell selection component 204, and battery monitoring circuit 206 can define a BMS configured to monitor all cells 200. Specifically, as shown, a first battery monitoring circuit 206 can be configured to monitor a first subgroup 201A of the multiple battery cells 200, and a second battery monitoring circuit 206B can be configured to monitor a second subgroup 201B of the multiple battery cells 200. In some cases, the second subgroup differs from the first subgroup and includes a different number of battery cells than the first subgroup. In this case, power supply circuit 202A can be configured differently from power supply circuit 202B to indicate the different number of battery cells being monitored (and ultimately define the different numbers of input currents or voltages for power supply circuits 202A and 202B).

[0029] For example, the first power supply circuit 202A can be configured to power the first battery monitoring circuit 206A based on a first subgroup 201A of multiple battery cells 200, and the second power supply circuit 202B can be configured to power the second battery monitoring circuit 206B based on a second subgroup 201B of multiple battery cells 200, wherein the first power supply circuit and the second power supply circuits 202A and 202B are configured to define substantially similar power supply to the first battery monitoring circuit 206A and the second battery monitoring circuit 206B.

[0030] As discussed in more detail below, power supply circuits 202A, 202B, and 202C may each include a configurable DC / DC converter based on one or more factors. One factor that can be used to configure the DC / DC converters of power supply circuits 202A, 202B, and 202C is the number of cells within each subgroup 201A, 201B, and 201C. The ratio of the input to output current or voltage of the DC / DC converter can be configurable based on the number of cells within each subgroup 201A, 201B, and 201C. Additional factors can also be used to configure the DC / DC converters of power supply circuits 202A, 202B, and 202C, such as factors defining the minimum number of channels used in different subgroups 201, and factors adjusting the DC / DC converters to compensate for manufacturing variations.

[0031] In some examples, the first power supply circuit 202A and the second power supply circuit 202B may each include a DC / DC power converter and a regulator, wherein each of the DC / DC power converters is configurable based on the number of battery cells being monitored by the first battery monitoring circuit 206A and the second battery monitoring circuit 206B, respectively (e.g., based on the number of cells in the first subgroup 201A and the number of cells in the second subgroup 201B). In some examples, each of the DC / DC power converters within the power supply circuits 202A and 202B can be configured to define a corresponding ratio of input to output (current or voltage), wherein, for each of the DC / DC power converters, the corresponding ratio is defined by a configurable parameter based on the number of monitored battery cells and based on the number of... Figure 2 The minimum number of battery cells within the different subgroups 201 of the BMS shown.

[0032] As an additional feature, it is also desirable for the power supply circuit to activate the battery cells when performing unit monitoring. Therefore, in some examples, the first power supply circuit 202A is configured to activate the first subgroup 201A of the plurality of battery cells 200 when the first battery monitoring circuit 206A monitors the first subgroup 201A, and the second power supply circuit is configured to activate the second subgroup 201B of the plurality of battery cells 200 when the second battery monitoring circuit 206B monitors the second subgroup 201B.

[0033] Furthermore, it may be desirable for the power supply circuit 202 to perform charge balancing of different cell blocks. Since the cells are already used to power the power supply circuit, in some cases, performing some charge balancing can be done as part of the function of the power supply circuit 202. Therefore, in some cases, the first power supply circuit 202A may be configured to perform charge balancing of the first subgroup 201A of battery cells relative to the second subgroup 201B of battery cells, and the second power supply circuit 202B may be configured to perform charge balancing of the second subgroup 201B of battery cells relative to the first subgroup 201A of battery cells. In other words, it may be desirable for the power supply circuit 202 to perform charge balancing of different subgroups 201 relative to other subgroups 201.

[0034] Figure 3 This is a block diagram illustrating an example power supply circuit that can be coupled to a battery cell and a load. Battery cell 300 may include a group of cells (eight cells in this example), or may include a subgroup of cells associated with a larger battery system. Load 306 may include components from... Figure 3 The battery monitoring circuit is powered by the other components shown. Cell selection component ( Figure 3(Not shown in the image) This allows each cell within the battery cell 300 to be individually connected to the load 306 to perform cell monitoring functions.

[0035] like Figure 3 As shown, the power supply circuit for load 306 may include a DC / DC power converter 308 and a linear regulator 310. Furthermore, the DC / DC power converter 308 is configurable. A first K-factor 312 can define at least a portion of the input-to-output ratio of the DC / DC power converter 308 based on the number of cells (N) in the plurality of cells 300 (in this example, N = 8, since there are eight cells) and based on the minimum number of cells used within the BMS (Nmin) (e.g., four cells, eight cells, or some other defined minimum value set by the user for a given situation). A second K-factor 314 can be defined during production testing of the circuit to adjust the DC / DC power converter 308 to account for manufacturing variations, thermal variations between any usage conditions, or other factors that may affect circuit operation. Component 315 functionally illustrates a combination of the first K-factor 312 and the second K-factor 314 to define a combined K-factor (e.g., K'). #M The combined K-factor defines the input-to-output ratio of the DC / DC converter 308 based on information defined by the first K-factor 312 and the second K-factor 314. Thus, the DC / DC power converter 308 can be adapted for use cases where circuit M is used to supply power to a battery monitoring circuit (e.g., load 306) to monitor eight of the multiple units 300.

[0036] In some examples, the first K factor 312 is based on Figure 3 The variables N and Nmin are defined as shown, and the second K factor can be defined at least partially by the variable M. N can define the number of cells attached to the circuit, in which case the number can be 8. Nmin can define the minimum number of cells connected to any corresponding circuit within a larger BMS. In some cases, M is simply an identifier for a specific circuit, in which case M can identify or define manufacturing variations in the integrated circuit manufacturing process associated with that specific circuit. Moreover, in some cases, the value M can also identify the total number of power supply circuits within the BMS (and the corresponding number of subgroups of cell blocks) (similar to...). Figure 2 (How M is labeled in the text). Therefore, in some cases, the K factor used in any given power supply circuit can also be defined based on the total number of power supply circuits in use (which may also correspond to the total number of cell blocks or cell subgroups used within the BMS).

[0037] Some exemplary markings for voltage and current are also included. Figure 3 As shown in the image. V VSThis refers to the voltage associated with cell 300, which can correspond to the number of cells (N) within cell 300 multiplied by the voltage (V) associated with one cell. CELL ). I VS This refers to the current within the DC / DC converter 308, which includes the current determined by the combined K-factor (e.g., K'). #M ) Adjusted input current I regin#M The combined K-factor defines the input-to-output ratio of the DC / DC converter based on information defined by the first K-factor 312 and the second K-factor 314. REGIN This refers to the regulated input voltage on the linear regulator 310, and V REGOUT This refers to the regulated output voltage across load 306. REG This refers to the regulated current from the linear regulator 310, and I REGOUT#M This refers to the regulated current supplied to the load 306 from the linear regulator 310. In some examples, the circuitry of this disclosure can appropriately control and define I for a given situation. REGOUT#M This given situation describes the number of battery cells in cell 300 and other factors that may be discussed here.

[0038] Figure 4 This is a block diagram illustrating an example of several power supply circuits that can be coupled to different groups of battery cells and different loads. The battery cells of the entire battery system can include several subgroups of cells associated with a larger battery system. In this example, three subgroups of battery cells are shown: subgroup 401A, subgroup 401B, and subgroup 401C (collectively referred to as subgroup 401). Furthermore, one or more subgroups within subgroup 401 may have a different number of battery cells than the other subgroups. For example, in… Figure 4 Subgroup 401A includes eleven battery cells, subgroup 401B includes twelve battery cells, and subgroup 401C includes eight battery cells. The technology disclosed herein improves power supply in these types of situations, allowing similar power supply circuitry to be used for each situation and enabling the DC / DC converter to be configured with different K-factors to help balance the supply in these different situations.

[0039] Loads 406A, 406B, and 406C (collectively referred to as loads 406) may include components made of... Figure 4 The battery monitoring circuit is powered by the other components shown. Cell selection component ( Figure 4 (Not shown) This allows each cell within a subgroup 401 of the battery cell to be individually connected to the load 406 in order to perform cell monitoring functions.

[0040] like Figure 4As shown, the power supply circuit for load 406 can each include a DC / DC power converter and a regulator, which may include a linear regulator. Various components of the DC / DC power converter are... Figure 4 The linear regulators are shown and discussed in detail below. The linear regulators are labeled as elements 410A, 410B, and 410C (collectively referred to as linear regulator 410).

[0041] according to Figure 4 The first circuit 402A may include a first DC / DC power converter, which includes transistors 418A and 419A, and a controller 416A that controls the on / off states of transistors 418A and 419A to transmit pulse signals to inductor 420A and output capacitor 422A. The timing of the on / off switching of transistors 418A and 419A can be controlled via the controller 416A according to a timing scheme, which may be at least partially based on one or more configurable parameters. In particular, the controller 416A may perform control based on one or more programmable factors that define the input-to-output ratio of the DC / DC power converter. A first K-factor 412A may define at least a portion of the input-to-output ratio of the DC / DC power converter of circuit 402A based on the number of cells in subgroup 401A (eleven cells in this example) and the minimum number of cells (Nmin) used in any block within the BMS. The number of cells used and the minimum number of cells (Nmin) may be programmable values ​​selected by the user in any given usage scenario. exist Figure 4 In the example, Nmin can be equal to eight (8), as this is the minimum number of cells within any subgroup 401 provided and monitored by circuit 402. A second K-factor 414A can be defined during production testing of the circuit to adjust the DC / DC power converter to account for manufacturing variations, thermal variations between any usage conditions, or other factors that may affect circuit operation. Moreover, as mentioned above, in some cases, the second K-factor can also be adjusted based on the total number of power supply circuits in the BMS (which corresponds to the number of subgroups 401). Element 415A functionally describes a combination of the first K-factor 412A and the second K-factor 414A to define a combined K-factor (e.g., K'). #1 The combined K-factor defines the input-to-output ratio of the DC / DC converter based on information defined by the first K-factor 412A and the second K-factor 414A. Thus, the DC / DC power converter of circuit 402A can be adapted for use in situations where circuit 402A is used to supply power to a battery monitoring circuit (e.g., load 406A) to monitor eleven battery cells.

[0042] according to Figure 4The second circuit 402B may include a second DC / DC power converter, which includes transistors 418B and 419B, and a controller 416B that controls the on / off states of transistors 418B and 419B to transmit pulse signals to inductor 420B and output capacitor 422B. The timing of the on / off switching of transistors 418B and 419B can be controlled via the controller 416B according to a timing scheme, which can be at least partially based on one or more configurable parameters. In particular, the controller 416B can perform control based on one or more programmable factors that define the input-to-output ratio of the DC / DC power converter. A first K-factor 412B can define at least a portion of the input-to-output ratio of the DC / DC power converter of circuit 402B based on the number of cells in subgroup 401B (twelve cells in this example) and based on the minimum number (Nmin) of cells associated with any subgroup of cells 401. Again, in this case, Nmin can be equal to eight (8), because this is the minimum number of cells within any subgroup 401 provided and monitored by circuit 402. A second K-factor 414B can be defined during production testing of the circuit to adjust the DC / DC power converter to account for manufacturing variations, thermal variations between any usage conditions, or other factors that may affect circuit operation. Element 415B functionally describes a combination of the first K-factor 412B and the second K-factor 414B to define a combined K-factor (e.g., K'). #2 The combined K-factor defines the input-to-output ratio of the DC / DC converter of circuit 402B based on information defined by the first K-factor 412B and the second K-factor 414B. Thus, the DC / DC power converter of circuit 402B can be adapted for use cases where circuit 2 is used to supply power to the battery monitoring circuit (e.g., load 406B) to monitor twelve battery cells.

[0043] According to this disclosure, any number of circuits can be used in a larger BMS. Figure 4 Three circuits are shown, but additional circuitry may be needed to monitor additional battery cells. Similar to the explanation above, according to... Figure 4The third circuit 402C may include a third DC / DC power converter, which includes transistors 418C and 419C, and a controller 416C that controls the on / off states of transistors 418C and 419C to transmit pulse signals to inductor 420C and output capacitor 422C. The timing of the on / off switching of transistors 418C and 419C can be controlled via controller 416C according to a timing scheme, which can be at least partially based on one or more configurable parameters. In particular, controller 416C can perform control based on one or more programmable factors that define the input-to-output ratio of the DC / DC power converter. A first K-factor 412C can define at least a portion of the input-to-output ratio of the DC / DC power converter of circuit 402C based on the number of cells in subgroup 401C (eight cells in this example) and based on the minimum number of cells associated with the subgroup of cells 401. Figure 4 In the example, Nmin can be equal to eight (8), as this is the minimum number of cells within any subgroup 401 provided and monitored by circuit 402. A second K-factor 414C can be defined during production testing of the circuit to adjust the DC / DC power converter to account for manufacturing variations, thermal variations between any usage conditions, or other factors that may affect circuit operation. Element 415C functionally describes a combination of the first K-factor 412C and the second K-factor 414C to define a combined K-factor (e.g., K'). #M The combined K-factor defines the input-to-output ratio of the DC / DC converter of circuit 402C based on information defined by the first K-factor 412C and the second K-factor 414C. Thus, the DC / DC power converter of circuit 402C can be adapted for use cases where circuit M is used to provide power to a battery monitoring circuit (e.g., load 406C) to monitor eight battery cells.

[0044] Figure 4 The designation "M" typically corresponds to any positive integer, meaning that any number of circuits can be used in a larger BMS to monitor any number of subgroups or blocks of cells. HV- and HV+ refer to the negative and positive terminals of a larger battery system comprising each subgroup 401 of battery cells. Some exemplary markings for voltage and current are also included. Figure 4 As shown in the image. V VS This refers to the voltage associated with each subgroup 401 of the cells, which can correspond to the number of cells (N) within each subgroup 401 multiplied by the voltage (V) associated with one cell. CELL ). I VS This refers to the current within each DC / DC converter, which includes the current determined by the combined K-factor (e.g., K'). #M K'#2 Or K' #1 ) Adjusted input current I regin#M I regin#2 Or I regin#1 The combined K-factor defines the input-to-output ratio of the DC / DC converter based on information defined by the first K-factors 412A, 412B, 412C and the second K-factors 414A, 414B, 414C. REGIN This refers to the regulated input voltage on the linear regulators 410A, 410B, and 410C, and V REGOUT This refers to the regulated output voltage across loads 406A, 406B, and 406C. REG This refers to the supply current of the linear regulators 410A, 410B, and 410C, and I REGOUT This refers to the regulated current from the linear regulators 410A, 410B, and 410C that supplies power to the loads 406A, 406B, and 406C. In some examples, the circuitry of this disclosure can appropriately control and define I for different situations. REGOUT This is to indicate the number of battery cells in each subgroup 401 and other possible factors discussed herein. Although similar notation is used... Figure 4 The currents and voltages shown in the different circuits 402 are as follows, but the actual values ​​of these currents and voltages will generally be different for each circuit in 402 because different K factors are used in the different DC / DC converters of each circuit in 402.

[0045] Figure 5 This is a block diagram illustrating an example power supply circuit that can be coupled to battery cell 501 and load 506. As described in more detail below, the technology of this disclosure allows power to be supplied to an external load 530 in addition to powering the load 506, which may represent battery monitoring circuitry. Figure 5As shown, the circuit may include integrated circuit 502 and additional external circuit elements (e.g., capacitor 522 and inductor 520) that operate together with integrated circuit 502 to define a DC / DC power converter. Similar to other examples above, transistors 518 and 519 are controlled by controller 516. Specifically, controller 516 controls the on / off states of transistors 518 and 519 to deliver pulse signals to inductor 520 and output capacitor 522. The timing of the on / off switching of transistors 518 and 519 can be controlled via controller 516 according to a timing scheme, which can be at least partially based on one or more configurable parameters. In particular, controller 516 can perform control based on one or more programmable factors that define the input-to-output ratio of the DC / DC power converter. A first K-factor 512 can define at least a portion of the input-to-output ratio of the circuit's DC / DC power converter based on the number of cells being monitored within a larger BMS (eleven cells in this example) and based on the minimum number being monitored (Nmin). During production testing of the circuit, a second K-factor 514 can be defined to adjust the DC / DC power converter to account for manufacturing variations, thermal variations between any usage conditions, or other factors that may affect circuit operation. Component 515 functionally represents a combination of the first K-factor 512 and the second K-factor 514 to define a combined K-factor (e.g., K'). #1 The combined K-factor defines the input-to-output ratio of the DC / DC converter based on information defined by the first K-factor 512 and the second K-factor 514. Thus, the DC / DC power converter of the circuit can be adapted for use cases where the circuit is used to provide power to a battery monitoring circuit (e.g., load 506) to monitor eleven battery cells.

[0046] Figure 5 The example also shows an external load 530, which is a load different from load 506. External load 530 may include an additional load that can be powered by the circuitry described herein. When the Vregin voltage decreases, the power consumption within the circuitry and at the linear regulator can decrease. This reduction in power consumption resulting from the power supply techniques of this disclosure allows for additional possibilities of increasing the current consumption of additional external circuitry that can be powered by the internal linear voltage regulator (Vregut). Therefore, in some examples, the power supply circuitry of this disclosure may be permitted to be used with external load 530 in addition to the monitoring circuitry represented by load 506. In effect, by reducing power consumption within the circuitry, the ability of the power supply circuitry to power external load 530 is improved. Figure 5 The other current and voltage markings shown are generally similar to those above. Figure 3 and Figure 4The aforementioned values, although the actual current and voltage values ​​may vary due to different configurations of the DC / DC converter.

[0047] Figure 6 This is another block diagram illustrating an example power supply circuit that can be coupled to battery cell 601 and load 606. As described in more detail below, the techniques and circuitry of this disclosure can allow the power supply circuitry to perform other functions of battery cell 601, such as cell excitation and / or cell block balancing.

[0048] like Figure 6 As shown, the circuit may include an integrated circuit 602 and additional external circuit elements (e.g., capacitors 621, 622 and inductor 620) that operate together with the integrated circuit 602 to define a DC / DC power converter. Transistors 618, 619 are controlled by a controller 616. In particular, the controller 616 can control the on / off states of transistors 618, 619 to deliver pulse signals to inductor 620 and output capacitor 622. The timing of the on / off switching of transistors 618, 619 can be controlled via the controller 616 according to a timing scheme, and this timing scheme can be at least partially based on one or more configurable parameters. According to the techniques of this disclosure, the controller 616 can perform control based on one or more programmable factors that define the input-to-output ratio of the DC / DC power converter. A first K-factor 612 can define at least a portion of the input-to-output ratio of the circuit's DC / DC power converter based on the number of units being monitored (eleven units in this example) and based on the minimum number of units being monitored within a larger BMS. During production testing of the circuit, a second K-factor 614 can be defined to adjust the DC / DC power converter to account for manufacturing variations, thermal variations between any usage conditions, or other factors that may affect circuit operation. Component 615 functionally describes a combination of the first K-factor 612 and the second K-factor 614 to define a combined K-factor (e.g., K'). #1 The combined K-factor defines the input-to-output ratio of the DC / DC converter based on information defined by the first K-factor 612 and the second K-factor 614. Thus, the DC / DC power converter of the circuit can be adapted for use cases where the circuit is used to provide power to a battery monitoring circuit (e.g., load 606) to monitor eleven battery cells.

[0049] Figure 6 The example also shows an input resistor 640 and an output resistor 642, which may include parasitic resistances that may exist in resistive circuit elements or electrical connections. For example, the input resistor 640 may cause a voltage drop in a given cell, such as U. drop =R wire *I regin#1 / k' #1 , where R wire This is the input resistance associated with component 640 (which may represent the parasitic resistance of a wire or other electrical connection). I regin#1 and k' #1 exist Figure 6 The K-factor is labeled and generally corresponds to the adjusted current and the combined K-factor, as described here. Therefore, in this example, the K-factor is defined to affect U. drop U drop It can also be used to achieve cell balancing of battery cell 601 relative to other cell blocks within a larger BMS. Furthermore, for example, by connecting the input resistor 640 and the output resistor 642 to the input and output of each battery cell 601, a voltage drop or increase can be achieved in the battery cell 601 to draw or add charge. When performing such cell block balancing, the input capacitor 621 and the output capacitor 622 can operate as charge accumulation devices.

[0050] Therefore, in some examples, in addition to powering the monitoring circuitry represented by load 606, the power supply circuitry of this disclosure can allow for charge balance between different blocks of the battery cells (e.g., between battery cell 601 and another block of the battery cell). In practice, by means of… Figure 6 The circuitry shown performs cell balancing, which can reduce or potentially eliminate other cell block balancing functions that the load 606 may additionally perform. Furthermore, in some examples, an excitation signal can be sent via the output resistor 642 to excite one or more cells 601 simultaneously with the load 606 performing cell monitoring. The excitation can occur at one or more frequencies and may be useful when the load 606 performs impedance measurements on a given cell.

[0051] Compared to a linear regulator, the circuit described herein achieves reduced current consumption (defined by the K-factor) and also reduces voltage drop, thus preventing systematically incorrect voltage measurements performed by integrated circuit 602. In some examples, this voltage drop can be reduced by a factor of two or more compared to a circuit that only includes a linear rule.

[0052] Table 1 shows some example ratios for high-voltage battery systems that can be defined by the K-factor, where the battery monitoring circuit is configured to monitor 4, 8, 12, and 18 cells per circuit. In Tables 1 and 2, commas are used to indicate decimal points.

[0053] Table 1:

[0054]

[0055] Table 2 shows some example ratios that can be defined by the K-factor for high-voltage battery systems, where the battery monitoring circuit is configured to monitor. For different systems that monitor only 12 and 18 cells, these factors may be higher and the total discharge current may become lower.

[0056] Table 2:

[0057]

[0058] The desired input-to-output ratio of the DC / DC converter in the power supply circuit can be defined by a K-factor. This can include a first K-factor defining the minimum number of channels used in the BMS, and the actual number of channels for each power supply circuit in the BMS. The user can define the actual number of channels and the minimum number of channels for a given situation, and this can also be programmed into the circuit (in programmable memory). Furthermore, the total K-factor can also depend on a second K-factor, which can include a value determined during production testing of the circuit. In some examples, the second K-factor can be permanently stored in the circuit to compensate for current consumption I. reginX The mismatch. The second K-factor can also be a function of temperature to compensate for the temperature characteristics of current consumption. The various elements labeled in the figure to represent the K-factor can also represent programmable memory that stores the K-factor in the circuit.

[0059] The technology disclosed herein offers several advantages. Even with variations in the number of monitored cells in each circuit within a large battery system, substantially equal current consumption can be achieved across all cells. The total power consumption required to monitor battery cells can be reduced, and the power consumption of each circuit (e.g., at the linear regulator) decreases as the Vregn voltage decreases. As described above, this provides the possibility of increasing the current consumption of additional external circuitry, which can be powered by an internal linear voltage regulator (Vregut), such as referenced... Figure 5 The explanation given.

[0060] Furthermore, the voltage drop (smaller I_Vs) caused by the wires between the battery cells and the BMS pins can be reduced, and therefore, if individual cell voltages are measured, the highest-voltage cells (e.g., cells sharing the VS network for cell voltage measurement) and the lowest-voltage cells (e.g., cells sharing the GND network for cell voltage measurement) in the system are less affected by errors. Additionally, if block voltages are measured for a block of cells, systematic errors in that block voltage measurement can be reduced.

[0061] For reference Figure 6As explained, cell block balancing in the system is also possible through adaptation of the K_X_N_min factor. Furthermore, the described circuitry provides the possibility of modulating the current of the attached cells. This can provide a desired way to excite the cells at a specific (even very low) frequency during cell monitoring. Such excitation may be needed to measure the impedance of the attached battery cells. The circuitry can perform K-factor modulation (square wave, sine wave, or other modulation at one or more frequencies) at a certain frequency f_stim. When this modulation is performed, and current and voltage are measured simultaneously, the cell impedance at that frequency can be measured by the circuitry.

[0062] The DC / DC implementation described herein is merely an example. Various other DC / DC structures exist that can also be used according to this disclosure. The DC / DC power converter of this disclosure can achieve a stable conversion ratio between the input current and the output current. Furthermore, a switched-capacitor DC / DC can be used, but this presents more limitations in terms of conversion factor adaptation.

[0063] Figure 7 This is a flowchart consistent with the technology disclosed herein. For example... Figure 7 As shown, the method performed by the circuit may include powering the battery monitoring circuit 106 using a power supply circuit 102 and a plurality of battery cells 100 of the battery system, wherein the power supply circuit 102 includes a DC / DC power converter (701). The method may also include controlling the DC / DC power converter to control the power supply (702) based on a plurality of monitored battery cells among the plurality of battery cells, for example by controlling the DC / DC power converter according to configurable parameters.

[0064] As described herein, configurable parameters may include one or more K-factors, which configure the DC / DC power converter to define the input-to-output ratio of the DC / DC power converter. Configurable parameters may be based on the number of monitored battery cells and the minimum number of battery cells being monitored within the BMS.

[0065] The method may also include individually coupling each battery cell 100 to the battery monitoring circuit 106, while simultaneously powering the battery monitoring circuit based on multiple cells. In some examples, the DC / DC power converter is configurable based on a first K-factor and a second K-factor, the first K-factor being based on the number of monitored battery cells and the minimum number of battery cells being monitored within the BMS, and the second K-factor being defined during production testing of the battery management circuit to adjust the DC / DC power converter. The second K-factor can compensate for operational variations in the battery management circuit caused by thermal changes.

[0066] In other examples, Figure 7The method shown may also include energizing at least some of the multiple cells while monitoring these cells in the battery monitoring circuit 106. Furthermore, in some examples, Figure 7 The method shown may also include using power supply circuit 102 to perform charge balancing of one block of battery cells relative to another block of battery cells.

[0067] The following clauses may describe one or more aspects of this disclosure.

[0068] Clause 1 - A battery management circuit configured to monitor a plurality of battery cells, the battery management circuit comprising: a battery monitoring circuit; and a power supply circuit configured to supply power to the battery monitoring circuit based on the plurality of battery cells, wherein the power supply circuit includes a DC / DC power converter and a regulator, and wherein the DC / DC power converter is configurable based on the number of monitored battery cells among the plurality of battery cells.

[0069] Clause 2 - The battery management circuit as described in Clause 1, wherein the DC / DC power converter is configurable to define the input-to-output ratio of the DC / DC power converter.

[0070] Clause 3 - Battery management circuit as described in Clause 2, wherein the ratio is defined by a configurable parameter based on the number of monitored battery cells.

[0071] Clause 4 - Battery management circuit according to Clause 3, wherein the configurable parameters are based on the number of monitored battery cells and on the minimum number of battery cells being monitored within the battery management system (BMS).

[0072] Clause 5 - The battery management circuit according to any one of Clauses 1-4 further includes one or more elements configured to individually couple each monitored battery cell to the battery monitoring circuit while simultaneously powering the battery monitoring circuit based on the plurality of cells.

[0073] Clause 6 - A battery management circuit according to any one of Clauses 1-5, wherein the DC / DC power converter is configurable based on a first K-factor and a second K-factor, the first K-factor being defined based on the number of monitored battery cells and based on the minimum number of battery cells being monitored by the BMS, and the second K-factor being defined during production testing of the battery management circuit to adjust the DC / DC power converter.

[0074] Clause 7 - The battery management system as described in Clause 6, wherein the second K-factor compensates for operational changes in the battery management circuitry caused by thermal variations.

[0075] Clause 8 - A battery management system according to any one of Clauses 1-7, wherein the power supply circuit is further configured to energize the plurality of units while the battery monitoring circuit monitors these units.

[0076] Clause 9 - A battery management system according to any one of Clauses 1-8, wherein the power supply circuitry is further configured to perform charge balancing of the plurality of battery cells relative to battery cells in one or more other groups within the BMS.

[0077] Clause 10 - A method comprising: powering a battery monitoring circuit using a power supply circuit of a battery system and a plurality of battery cells, wherein the power supply circuit includes a DC / DC power converter and a regulator, and the DC / DC power converter is controlled according to configurable parameters, the configurable parameters being configurable based on the number of monitored battery cells among the plurality of battery cells.

[0078] Clause 11 - The method according to Clause 10, wherein the configurable parameter configures the DC / DC power converter to define the input-to-output ratio of the DC / DC power converter.

[0079] Clause 12 - The method according to Clause 10 or 11, wherein the configurable parameter is based on the number of monitored battery cells and on the minimum number of battery cells being monitored within the BMS.

[0080] Clause 13 - The method according to any one of Clauses 10-12 further includes: individually coupling each battery cell in the battery cells to the battery monitoring circuit, while simultaneously powering the battery monitoring circuit based on the plurality of cells.

[0081] Clause 14 - The method according to any one of Clauses 10-13, wherein the DC / DC power converter is configurable based on a first K-factor and a second K-factor, the first K-factor being based on the number of monitored battery cells and the minimum number of battery cells being monitored within the BMS, and the second K-factor being defined during production testing of the battery management circuit to adjust the DC / DC power converter.

[0082] Clause 15 - The method according to Clause 14, wherein the second K factor compensates for operational changes in the battery management circuit caused by thermal variations.

[0083] Clause 16 - The method according to any one of Clauses 10-15 further includes: stimulating at least some of the plurality of cells while the battery monitoring circuit monitors these cells.

[0084] Clause 17 - The method according to any one of Clauses 10-16 further includes: performing charge balancing of the plurality of battery cells using the power supply circuit, wherein the charge balancing is associated with one or more other groups of battery cells within the BMS.

[0085] Clause 18 - A battery management system (BMS) configured to monitor a plurality of battery cells arranged in series, the BMS comprising: a first battery monitoring circuit configured to monitor a first subgroup of the plurality of battery cells; a second battery monitoring circuit configured to monitor a second subgroup of the plurality of battery cells, wherein the second subgroup is different from the first subgroup, and wherein the second subgroup includes a different number of battery cells than the first subgroup; a first power supply circuit configured to power the first battery monitoring circuit based on the first subgroup of the plurality of battery cells; and a second power supply circuit configured to power the second battery monitoring circuit based on the second subgroup of the plurality of battery cells, wherein the first power supply circuit and the second power supply circuit are configured to define substantially similar power supplies to the first battery monitoring circuit and the second battery monitoring circuit.

[0086] Clause 19 - The BMS as described in Clause 18, wherein the first power supply circuit and the second power supply circuit each include a DC / DC power converter and a regulator, and wherein each of the DC / DC power converters is configurable based on the number of battery cells being monitored by the first battery monitoring circuit and the second battery monitoring circuit, respectively.

[0087] Clause 20 - A BMS as described in Clause 18 or 19, wherein each of the DC / DC power converters is configurable to define a corresponding ratio of input to output, wherein for each of the DC / DC power converters, the corresponding ratio is defined by a configurable parameter based on the number of battery cells being monitored and based on the minimum number of battery cells being monitored using the BMS.

[0088] Clause 21 - A BMS according to any one of Clauses 18-20, wherein the first power supply circuit is configured to energize a first subgroup of the plurality of units while a first battery monitoring circuit monitors the first subgroup, and wherein the second power supply circuit is configured to energize a second subgroup of the plurality of units while a second battery monitoring circuit monitors the second subgroup.

[0089] Clause 22 - BMS according to any one of Clauses 18-21, wherein the first power supply circuit is configured to perform charge balancing of the first subgroup of the battery cell relative to the second subgroup of the battery cell, and wherein the second power supply circuit is configured to perform charge balancing of the second subgroup of the battery cell relative to the first subgroup of the battery cell.

[0090] Various aspects and examples have been described in this disclosure. These aspects and other aspects and examples are within the scope of the following claims.

Claims

1. A battery management circuit configured to monitor a plurality of battery cells, the battery management circuit comprising: Battery monitoring circuit; as well as A power supply circuit is configured to power the battery monitoring circuit based on the plurality of battery cells, wherein the power supply circuit includes a DC / DC power converter and a regulator, and wherein the DC / DC power converter is configurable to define an input-to-output ratio based on both the number of battery cells monitored among the plurality of battery cells and the minimum number of battery cells being monitored by other battery management circuits within the battery management system (BMS).

2. The battery management circuit of claim 1 further includes one or more elements configured to individually couple each monitored battery cell to the battery monitoring circuit while simultaneously powering the battery monitoring circuit based on the plurality of cells.

3. The battery management circuit of claim 1, wherein the DC / DC power converter is configurable based on a first K-factor and a second K-factor, the first K-factor being defined based on the number of monitored battery cells and the minimum number of battery cells being monitored within the battery management system (BMS), and the second K-factor being defined during production testing of the battery management circuit to adjust the DC / DC power converter.

4. The battery management system of claim 3, wherein the second K-factor compensates for operational changes in the battery management circuit caused by thermal variations.

5. The battery management system according to claim 1, wherein the power supply circuit is further configured to energize the plurality of units, while the battery monitoring circuit monitors the units.

6. The battery management system of claim 1, wherein the power supply circuit is further configured to perform charge balancing of the plurality of battery cells relative to one or more other groups of battery cells within the battery management system (BMS).

7. A method for supplying power to a battery monitoring circuit, comprising: The battery monitoring circuit is powered by a battery system power supply circuit and multiple battery cells, wherein the power supply circuit includes a DC / DC power converter and a regulator, and The DC / DC power converter is controlled according to configurable parameters, which are configurable based on the number of monitored battery cells among the plurality of battery cells. The configurable parameters configure the DC / DC power converter to define the input-to-output ratio of the DC / DC power converter, wherein the ratio is based on both the number of battery cells monitored in the plurality of battery cells and the minimum number of battery cells being monitored by other battery management circuits within the battery management system (BMS).

8. The method according to claim 7, further comprising: Each battery cell in the battery unit is individually coupled to the battery monitoring circuit, while the battery monitoring circuit is powered based on the plurality of cells.

9. The method of claim 7, wherein the DC / DC power converter is configurable based on a first K-factor and a second K-factor, the first K-factor being based on the number of monitored battery cells and the minimum number of battery cells being monitored within the battery management system (BMS), and the second K-factor being defined during production testing of the battery management circuit to adjust the DC / DC power converter.

10. The method of claim 9, wherein the second K-factor compensates for operational changes in the battery management circuit caused by thermal variations.

11. The method of claim 7, further comprising: The battery monitoring circuit stimulates at least some of the plurality of units while monitoring the units.

12. The method of claim 7, further comprising: The power supply circuit is used to perform charge balancing of the plurality of battery cells, wherein the charge balancing is related to one or more other groups of battery cells within the battery management system (BMS).

13. A battery management system (BMS) configured to monitor a plurality of battery cells arranged in series, the BMS comprising: A first battery monitoring circuit is configured to monitor a first subgroup of the plurality of battery cells; A second battery monitoring circuit is configured to monitor a second subgroup of the plurality of battery cells, wherein the second subgroup is different from the first subgroup, and wherein the second subgroup includes a different number of battery cells than the first subgroup. The first power supply circuit is configured to power the first battery monitoring circuit based on the first subgroup of the plurality of battery cells; as well as The second power supply circuit is configured to power the second battery monitoring circuit based on the second subgroup of the plurality of battery cells. The first power supply circuit and the second power supply circuit are configured to provide substantially similar power to the first battery monitoring circuit and the second battery monitoring circuit, respectively. Each of the first and second power supply circuits includes a DC / DC power converter and a regulator, and each respective DC / DC power converter is configurable to define a corresponding input-to-output ratio of the respective DC / DC power converter, wherein the ratio is based on the number of battery cells monitored in a corresponding subgroup of the plurality of battery cells and the minimum number of battery cells in other subgroups of the battery cells being monitored by other battery management circuits within the BMS.

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