CN117134460A - Battery management system and battery pack - Google Patents

Battery management system and battery pack Download PDF

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Publication number
CN117134460A
CN117134460A CN202311118332.5A CN202311118332A CN117134460A CN 117134460 A CN117134460 A CN 117134460A CN 202311118332 A CN202311118332 A CN 202311118332A CN 117134460 A CN117134460 A CN 117134460A
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China
Prior art keywords
battery
equalization
voltage
period
module
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CN202311118332.5A
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Chinese (zh)
Inventor
许佳妮
李柳莹
仝晨安
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Tuoer Microelectronics Co ltd
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Tuoer Microelectronics Co ltd
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Priority to CN202311118332.5A priority Critical patent/CN117134460A/en
Publication of CN117134460A publication Critical patent/CN117134460A/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4207—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells for several batteries or cells simultaneously or sequentially
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • H01M10/482—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte for several batteries or cells simultaneously or sequentially
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
    • H02J7/0014—Circuits for equalisation of charge between batteries
    • H02J7/0019—Circuits for equalisation of charge between batteries using switched or multiplexed charge circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00308—Overvoltage protection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0047—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with monitoring or indicating devices or circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
    • H01M2010/4271—Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The embodiment of the application provides a battery management system and a battery pack. The battery management system comprises a sampling module, an equalization module and a control module. The sampling module is used for sampling the voltage difference between the adjacent branches as the battery voltage between the adjacent serial nodes connected by the adjacent branches. The balancing module is used for balancing the battery voltage between the adjacent serial nodes connected with the adjacent branches through connecting the adjacent branches. The control module is used for controlling the sampling module to sample according to the sampling period of the battery voltage and controlling the equalization module to equalize in the equalization period of the battery voltage according to the sampling result of the battery voltage in the sampling period. The control module also determines an equalization pause period of the battery voltage according to the sampling period of the battery voltage, so that the sampling period of the battery voltage is within the equalization pause period of the battery voltage, and the equalization pause period is a period for controlling the equalization module to pause equalization.

Description

Battery management system and battery pack
Technical Field
The embodiment of the application relates to the technical field of electronic circuits, in particular to a battery management system and a battery pack.
Background
Battery packs, which may include a plurality of batteries (e.g., lithium ion batteries) connected in series, are used in consumers such as electric vehicles to provide energy. With the continuous charge and discharge cycle of the batteries, the capacity difference between the batteries (i.e., the single batteries) in the battery pack is gradually increased, so that the usable capacity of the whole battery pack is affected, and therefore, the batteries in the battery pack are required to be subjected to balanced management, the inconsistency among the batteries is reduced, the usable capacity of the battery pack is improved, and the service life is prolonged. However, when the battery is balanced and started, the voltage sampling and protection judgment result of the battery is affected by the balance, so that the accuracy is reduced and the protection judgment is wrong.
In the current equalization management technology, sampling and voltage class protection of all batteries are suspended at the time of the battery equalization function, resulting in lower battery equalization efficiency.
Disclosure of Invention
In view of the above, embodiments of the present application provide a battery management system and a battery pack to at least partially solve the above-mentioned problems.
According to a first aspect of an embodiment of the present application, there is provided a battery management system connected to a plurality of series nodes in a battery module through a plurality of branches, respectively, wherein each branch is provided with an equalizing resistance. The battery management system includes: the sampling module is used for sampling the voltage difference between the adjacent branches and taking the voltage difference as the battery voltage between the adjacent serial nodes connected with the adjacent branches; the balancing module is used for balancing the battery voltage between adjacent serial nodes connected with the adjacent branches by connecting the adjacent branches; the control module is used for controlling the sampling module to sample according to the sampling period of the battery voltage and controlling the equalization module to equalize in the equalization period of the battery voltage according to the sampling result of the battery voltage in the sampling period. The control module also determines an equalization pause period of the battery voltage according to the sampling period of the battery voltage, so that the sampling period of the battery voltage is within the equalization pause period of the battery voltage, and the equalization pause period is a period for controlling the equalization module to pause equalization.
In another implementation of the present application, the battery management system further includes: and the protection judging module is used for comparing the voltage difference between the adjacent branches with the safety voltage range.
In another implementation of the present application, the battery management system further includes a protection module, and the control module controls to stop the operation of the equalization module when the voltage difference exceeds the safety voltage range.
In another implementation manner of the present application, the control module is specifically configured to control the protection judging module to detect and compare a voltage difference between adjacent branches and a safe voltage range in a protection judging period of a battery voltage, and control the protection judging period of the battery voltage to be within the equalization pause period.
In another implementation of the present application, the control module is further configured to: and controlling the protection judging module to shield and judge the under-voltage protection of the battery voltage when the protection judging period of the battery voltage is overlapped with the equalization period of the battery voltage.
In another implementation of the present application, the control module is further configured to: and controlling the protection judging module to shield and judge the overvoltage protection of the adjacent battery voltage of the battery voltage when the protection judging period of the battery voltage is overlapped with the equalization period of the adjacent battery voltage of the battery voltage.
In another implementation of the present application, the control module further determines an equalization pause period of the battery voltage according to sampling periods of adjacent battery voltages of the battery voltage such that the sampling periods of the adjacent battery voltages are within the equalization pause period of the battery voltage.
In another implementation manner of the present application, the control module is specifically configured to: and controlling the sampling module to carry out polling sampling on each battery voltage according to the sampling period of each battery voltage between adjacent series nodes in the plurality of series nodes.
In another implementation manner of the present application, the control module is specifically configured to: and controlling the sampling module to carry out polling sampling on each battery voltage according to the position sequence of the plurality of nodes connected in series.
In another implementation manner of the present application, the control module is specifically configured to: when the sampling period of the last polling voltage of the current polling voltages in the respective battery voltages arrives, control starts an equalization suspension period of the current polling voltage, and when the sampling period of the next polling voltage of the current polling voltage ends, control ends the equalization suspension period of the current polling voltage.
According to a second aspect of embodiments of the present application, there is provided a battery module and a battery management system according to the first aspect.
In the scheme of the embodiment of the application, the battery voltage between the adjacent battery nodes in series is independently sampled and balanced, and the sampling period of the battery voltage is in a period for controlling the balancing module to suspend the balancing of the battery voltage, so that the heating of the balancing resistor (for example, the heating of a chip) is reduced, and the reliability of the balancing process is improved. In addition, the sampling period and the equalization period of the battery voltage are multiplexed in a time-sharing manner, so that the equalization efficiency of each battery is improved.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the embodiments of the present application, and other drawings may be obtained according to these drawings for a person having ordinary skill in the art.
Fig. 1 is a schematic block diagram of a battery equalization system according to an example.
Fig. 2 is a schematic block diagram of a battery management system according to one embodiment of the application.
Fig. 3 is a schematic block diagram of the battery management system of the embodiment of fig. 2 performing an equalization operation in a battery equalization system.
Fig. 4 is a timing diagram of equalization control signals in the battery management system of the embodiment of fig. 2.
Fig. 5 is a block diagram of a battery pack according to another embodiment of the present application.
Detailed Description
In order to better understand the technical solutions in the embodiments of the present application, the following description will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which are derived by a person skilled in the art based on the embodiments of the present application, shall fall within the scope of protection of the embodiments of the present application.
The implementation of the embodiments of the present application will be further described below with reference to the accompanying drawings.
Referring to fig. 1, the battery balancing system includes a battery pack composed of a battery module 20 and a battery management system 100, and a load or charger 10. During the discharging phase of the battery pack, the battery management system 100 is connected between the battery module 20 and the load. During the charging stage of the battery pack, the battery management system 100 is connected between the battery module 20 and the charger 10, and the charger 10 is connected to an ac power source to store a computer in the battery module 20.
Further, the battery management system 100 may include a sampling module 110, an equalizing module 120, a protection judging module 130, and the like. The battery management system 100 also includes a battery equalization circuit. For example, the battery equalization circuit may include a plurality of batteries (e.g., battery 1, battery 2, battery 3, battery 4, battery 5), a plurality of equalization resistors (e.g., resistors R1, R2, R3, R4, R5, etc.), a plurality of equalization switches (e.g., S1, S2, S3, S4, S5, etc.), a plurality of capacitors (e.g., C1, C2, C3, C4, C5). Generally, the battery management system 100 is connected to a plurality of series nodes in the battery module 20 through a plurality of branches, respectively, and a plurality of batteries are connected in series through the plurality of series nodes, each branch being provided with an equalizing resistance.
In some cases, sampling, balancing, and protection decisions for the battery being balanced may deviate. For example, taking the battery 4 as an example, when the battery 4 is not balanced, the voltage to ground at the point V4 corresponds to the voltage to ground at the point V40, and the voltage to ground at the point V3 corresponds to the voltage to ground at the point V30, so the voltage difference between the points V4 and V3 is the voltage of the battery 4. When the equalization control of the battery 4 is turned on, the equalization switch S4 is turned on, a current flows in a loop formed by the battery 4, the equalization resistor R4, the equalization switch S4 and the equalization resistor R3, the voltage difference between V4 and V3 is the voltage on the equalization switch S4, but not the voltage of the battery 4, and an error occurs when the voltage difference between V4 and V3 is used as the voltage sampling result of the battery 4. Similarly, currents are present in both the balancing resistor R3 and the balancing resistor R4, so that the voltage sampling accuracy of the battery 5 and the battery 3 is poor, that is, the balancing process of the battery is performed simultaneously with the sampling process, and interference occurs.
In addition, the control module of the battery management system 100 may perform polling detection and judgment on each battery according to a certain period, for example, when V4 and V3 voltages are input as comparators, it may be determined that the battery 4 is under-voltage, and the battery 3 and the battery 5 have an over-voltage. That is, the equalization process and the protection judgment process of the battery are performed simultaneously, and interference occurs.
A battery management system 200 according to an embodiment of the present application will be described below with reference to fig. 2. The battery management system 200 is connected to a plurality of series nodes in the battery module through a plurality of branches, respectively. Each branch is provided with an equalizing resistor. An equalization switch may be provided between adjacent branches. Specifically, the battery management system 200 includes a sampling module 210, an equalization module 220, and a control module 230.
In addition, the sampling module 210 is configured to sample a voltage difference between adjacent branches (i.e., a voltage difference when the equalization switch between the adjacent branches is turned off) as a battery voltage between adjacent series nodes to which the adjacent branches are connected. I.e. the voltage difference in case of an equalization switch between adjacent branches being turned off.
In addition, the balancing module 220 is configured to balance the battery voltage between adjacent series nodes to which the adjacent branches are connected (the balancing switch between the adjacent branches is closed) by connecting the adjacent branches.
In addition, the control module 230 is configured to control the sampling module 210 to sample according to a sampling period of the battery voltage, and control the equalization module 220 to equalize during an equalization period of the battery voltage according to a sampling result of the battery voltage during the sampling period.
In addition, the control module 230 determines an equalization suspension period of the battery voltage according to the sampling period of the battery voltage, so that the sampling period of the battery voltage is within the equalization suspension period of the battery voltage, and the equalization suspension period is a period for controlling the equalization module 220 to suspend equalization.
In the scheme of the embodiment of the application, the battery voltages between the adjacent battery nodes in series are independently sampled and balanced, and the sampling period of the battery voltages is in a period for controlling the balancing module to suspend the balancing of the battery voltages, so that the heating of the balancing resistor is reduced, and the reliability of the balancing process is improved. In addition, the sampling period and the equalization period of the battery voltage are multiplexed in a time-sharing manner, so that the equalization efficiency of each battery is improved.
The equalization control process performed by the battery management system 200 of fig. 2 will be described in detail below in conjunction with the schematic block diagram of fig. 3. The battery equalization circuit of fig. 3 may have a type of configuration as the battery equalization circuit of fig. 1, and is not described here. Further, fig. 3 depicts 5 batteries in the battery module 20, which is only exemplary and should not be construed as limiting the number of batteries in the battery module 20, and as a typical example, the battery module 20 may include 16 batteries in series.
In this embodiment, the control module 230 may control the equalization period of the current battery voltage and the sampling period of the adjacent battery voltage to avoid being performed simultaneously, that is, the adjacent battery voltage is in the sampling period and the current battery voltage is in the equalization pause, in addition to controlling the sampling period and the equalization period of the current battery voltage (for example, the voltage of at least one unit battery) between the adjacent series nodes to be performed differently.
The timing chart of the battery voltage equalization control process shown in fig. 4 may be applied to the battery voltage (e.g., battery) between any adjacent series nodes in the battery module 20.
In the control timing of the battery voltage, T4 indicates an equalization suspension period of the battery voltage (for example, equalization of the battery voltage is suspended due to sampling operation of the battery voltage and its neighboring battery voltages), and T5 indicates an equalization period of the battery voltage. It can be seen that between T4 and T5 may be alternating periods during the equalization control, T4 and T5 forming T3 indicating the period of the equalization cycle, in a typical example, T3 may be several tens of ms in length.
In the equalization control process (t 0-t 5) of the battery module 20, the equalization period and the equalization suspension period of each battery may be as shown in table 1, and the equalization control process may include a plurality of polling periods t0-t1, t1-t2, t2-t3, t3-t4, t4-t5. For example, assume that battery 1, battery 3 are batteries requiring equalization, and battery 2, battery 4, battery 5, battery 6 do not perform equalization. Sampling was performed in accordance with the polling of battery 1, battery 2, … …, battery 5, battery 1, taking 3ms (T1) for one battery, and the time periods T0-T1, T1-T2, … …, T4-T5 in table 1 below were all 3ms, in this example t3=5×3ms.
Without loss of generality, the control module 230 may control the sampling module to poll and sample the respective battery voltages according to the order of the positions of the plurality of nodes in series. The order of the positions of the series nodes indicates the order of connection of the respective batteries. For example, battery 1, battery 2, battery 3, battery 4, and battery 5. As another example, battery 5, battery 4, battery 3, battery 2, and battery 1.
Specifically, the control module 30 may be configured to: when the sampling period of the last polling voltage of the current polling voltages in the respective battery voltages arrives, control starts the equalization suspension period of the current polling voltage, and when the sampling period of the next polling voltage of the current polling voltage ends, control ends the equalization suspension period of the current polling voltage. Each period of time is accurately and reliably switched, further improving the overall equalization efficiency of the battery module 20.
Continuing with the equalization control procedure of the present example, reference is made to table 1:
when the battery 1 is sampled, the battery 3 equalization is performed normally.
When the battery 2 sampling is performed, equalization of the battery 1 and the battery 3 is suspended.
When the sampling of the battery 3 is performed, the equalization of the battery 1 is performed normally.
When the sampling of the battery 4 is performed, the equalization of the battery 1 is performed normally, and the equalization of the battery 3 is suspended.
When the battery 5 is sampled, the battery 1 is balanced and suspended, and the battery 3 is balanced and normally performed.
When the battery 1 is sampled, the battery 3 equalization is performed normally.
TABLE 1
That is, in one polling period (t3=5x3ms) of T0 to T5, the equalization control signal of the battery 1 is T0 to T1 (off), T1 to T2 (off), T2 to T3 (on), T3 to T4 (on), and T4 to T5 (off). That is, the battery 1 is balanced in switching period, t4-t5 (off), t0-t1 (off), t1-t2 (off), t2-t3 (on), and t3-t4 (on). That is, in the equalization timing of the battery 1, t4=3×3ms, t5=t3—t4=6ms.
For another example, the equalization control signal of the battery 3 is t0-t1 (on), t1-t2 (off), t2-t3 (off), t3-t4 (off), and t4-t5 (on). I.e. the equalization switching period of the battery 3, t1-t2 (off), t2-t3 (off), t3-t4 (off), t4-t5 (on), t0-t1 (on). That is, in the equalization timing of the battery 3, t4=3×3ms, t5=t3—t4=6 ms.
In the equalization control signal of the battery voltage, a high level indicates that equalization is suspended, and a low level indicates that equalization is on, i.e., equalization is alternately performed. In the prior art, sampling of each battery is stopped when the equalization of each battery is started, and the equalization of each battery is stopped when the sampling of each battery is started.
That is, the adjacent cell voltages do not perform the equalization period at the same time. Alternatively, the equalization periods during which the equalization is performed may be all implemented as equalization pause periods, without affecting the equalization control accuracy, while the duty ratio of the equalization control signal of the battery voltage is reduced.
Without loss of generality, the control module 230 may determine the equalization suspension period of the battery voltage according to the sampling period of the adjacent battery voltages of the battery voltage, so that the sampling period of the adjacent battery voltages is within the equalization suspension period of the battery voltage, thereby further ensuring the sampling precision of each battery voltage of the battery module 20.
Further, the control module 230 may control the sampling module to perform polling sampling on each battery voltage according to the sampling period of each battery voltage between adjacent series nodes in the plurality of series nodes, so as to improve the equalization efficiency of each battery voltage while ensuring the sampling precision of each battery voltage of the battery module 20.
In other embodiments, in the case of performing the protection determination operation during the equalization control, the battery management system 200 further includes a protection determination module for comparing the voltage difference between the adjacent branches with the safe voltage range.
Specifically, the control module 230 is specifically configured to control the protection judging module to detect and compare the voltage difference between the adjacent branches and the safe voltage range in the protection judging period of the battery voltage, and control the protection judging period of the battery voltage to be within the equalization pause period.
Further, the control module 230 may also control to stop the operation of the equalization module when the voltage difference exceeds the safe voltage range. The protection module may control the operation of the stop equalization module by, for example, closing a switching tube that controls the equalization module.
It should be appreciated that the protection decision module may be implemented as a comparison circuit, the input of which may be connected to each series node, so that a comparison of the battery voltage to the safe voltage range may be quickly achieved. The protection judging period of the comparison circuit may be T2 (not shown in fig. 4).
Further, in the t4+t5 period, a protection judgment operation may be performed, but the under-voltage protection judgment of the battery voltage that is being equalized and the over-voltage protection judgment of the adjacent battery voltages are to be masked.
The protection judgment operation of each battery in the case of the above example is exemplarily shown below with reference to table 2:
TABLE 2
It will be appreciated that the length of time required for a round of protection determination (battery 1-battery 5) is much less than the length of time for a round of sampling (battery 1-battery 5). For example, the sampling operation is performed for one round requiring a long time 5*3 =15 ms (i.e., the polling period is the product of the number of batteries to be sampled and the polling period), and requires approximately 3ms (i.e., an example of a protection judgment period) to judge whether or not the batteries 1 to 5 trigger the protection judgment of the undervoltage or the overvoltage.
Without loss of generality, the control module 230 is also configured to: when the protection judging period of the battery voltage is overlapped with the equalization period of the battery voltage, the control protection judging module controls the protection judging module to shield and judge the under-voltage protection of the battery voltage. That is, in the periods T4 and T5, the protection judgment operation of the battery voltage may be performed, but the undervoltage judgment result of the battery voltage being equalized is masked or discarded.
Without loss of generality, the control module 230 is also configured to: when the protection judging period of the battery voltage is overlapped with the equalization period of the adjacent battery voltage of the battery voltage, the control protection judging module controls the protection judging module to shield the adjacent battery voltage of the battery voltage for overvoltage protection judgment. That is, in the periods T4 and T5, the protection judgment operation of the battery voltage may be performed, but the overvoltage judgment result of the adjacent battery voltage that is equalizing the battery voltage is masked or discarded.
Specifically, if the protection judgment module judges that the current battery voltage is under voltage or the adjacent battery voltage is over voltage, the protection judgment result information is shielded or discarded, and the operation which the protection module should execute when the protection is triggered is not executed. As an example of protection triggering, the protection module turns off a discharge switch between the battery management system 200 and the battery module 20 in case of an under-voltage, turns off a charge switch between the battery management system 200 and the battery module 20 in case of an over-voltage, sets or outputs an interrupt signal according to a protection signal, and the like. This is because the accuracy of the undervoltage judgment and the accuracy of the overvoltage judgment of the adjacent battery voltage can be improved by adopting the above-described embodiment when the equalization of the battery voltage is underway.
It should be understood that in performing the equalization control for the plurality of batteries, the first and last battery of the plurality of batteries are determined as neighboring batteries for the polling sampling algorithm of the plurality of batteries. That is, in the above example, the battery 1 and the battery 5 are adjacent batteries. For example, battery 1 is balanced and suspended while battery 5 sampling is performed. For another example, if neither battery 1 nor battery 5 is to be equalized, battery 5 is equalized while battery 1 is in suspension while battery 5 sampling is in progress, and battery 5 is in suspension while battery 1 sampling is in progress.
As another example, alternatively, T6 indicates a period during which equalization suspension is suspended, for example, a period during which equalization of the battery voltage is suspended due to a protection judgment of the battery voltage and its neighboring battery voltages. It should be appreciated that during the equalization pause period indicated by T6, each battery may perform a poll sample and not mask the under-voltage protection determination or over-voltage protection determination of each battery. It should be appreciated that the plurality of polling periods may form a polling period, and that the equalization pause period may be performed every plurality of polling periods, for example, assuming t7=1s, T6 is performed after 55 polling periods (t3×55=990 ms) have been performed, i.e., t6=10 ms. That is, in the equalization suspension period of T6, equalization of both T1 and T3 is suspended, and sampling of the battery 1-5 proceeds normally.
That is, the order of execution of the sampling operations of the present example is unchanged from the above example, and equalization of both the battery 1 and the battery 3 is suspended. It will be appreciated that during the period of T6, any of the batteries, such as battery 1-battery 5, is not shielded, whether over-voltage or under-voltage occurs, as shown in table 3:
TABLE 3 Table 3
Further, in the case where the protection judging period of the battery voltage is within the equalization suspending period, that is, in the T6 period, equalization is suspended due to the protection judging operation, there is no need to mask the under-voltage judging result of the battery voltage being equalized nor the over-voltage judging result of the adjacent battery voltage in the T6 period, so that the protection judgment is performed for each battery more reliably. That is, in the period T6, if the battery voltage being sampled drops for some reason below the undervoltage protection threshold (not belonging to the safety voltage range), the undervoltage protection can be responded and executed by the protection module, for example, the discharge switch between the battery management system 200 and the battery module 20 is turned off, the undervoltage protection signal is set, and the undervoltage interrupt signal is output. If the adjacent voltage rises for some reason, it is higher than the overvoltage protection threshold (not belonging to the safety voltage range), the overvoltage protection can be responded by the protection module to perform corresponding actions, for example, turning off the charge switch between the battery management system 200 and the battery module 20, setting the overvoltage protection signal, and outputting the overvoltage interrupt signal.
Further, in the case where the input terminal of the comparison circuit is connected to each of the series nodes, the comparison of the battery voltage with the safety voltage range can be quickly and continuously achieved. In this case, in the period other than T6, the battery voltage being equalized triggers an undervoltage, and the adjacent battery voltage triggers an overvoltage (for example, excluding factors such as the equalization operation and the sampling operation affecting the protection judgment), the undervoltage protection of the battery voltage or the overvoltage protection response of the adjacent battery voltage will be delayed until the next T6 period.
Fig. 5 illustrates a battery pack 500 according to another embodiment of the present application. The battery pack 500 includes the battery module 20 and the battery management system of the respective embodiments described above.
Thus, particular embodiments of the present subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may be advantageous.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.
In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, as relevant to see a section of the description of method embodiments.
The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and variations of the present application will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the application are to be included in the scope of the claims of the present application.

Claims (11)

1. A battery management system connected to a plurality of series nodes in a battery module through a plurality of branches, respectively, wherein each branch is provided with an equalization resistor, the battery management system comprising:
the sampling module is used for sampling the voltage difference between the adjacent branches and taking the voltage difference as the battery voltage between the adjacent serial nodes connected with the adjacent branches;
the balancing module is used for balancing the battery voltage between adjacent serial nodes connected with the adjacent branches by connecting the adjacent branches;
the control module is used for controlling the sampling module to sample according to the sampling period of the battery voltage and controlling the equalization module to equalize in the equalization period of the battery voltage according to the sampling result of the battery voltage in the sampling period;
the control module further determines an equalization pause period of the battery voltage according to the sampling period of the battery voltage, so that the sampling period of the battery voltage is within the equalization pause period of the battery voltage, and the equalization pause period is a period for controlling the equalization module to pause equalization.
2. The circuit of claim 1, further comprising:
and the protection judging module is used for comparing the voltage difference between the adjacent branches with the safety voltage range.
3. The circuit of claim 2, further comprising a protection module, the control module further controlling to cease operation of the equalization module when the voltage difference exceeds the safe voltage range.
4. The circuit of claim 2, wherein the control module is specifically configured to control the protection determination module to detect and compare a voltage difference between adjacent branches with a safe voltage range during a protection determination period of a battery voltage, and to control the protection determination period of the battery voltage to be within the equalization pause period.
5. The circuit of claim 4, wherein the control module is further to: and controlling the protection judging module to shield and judge the under-voltage protection of the battery voltage when the protection judging period of the battery voltage is overlapped with the equalization period of the battery voltage.
6. The circuit of claim 4, wherein the control module is further to: and controlling the protection judging module to shield and judge the overvoltage protection of the adjacent battery voltage of the battery voltage when the protection judging period of the battery voltage is overlapped with the equalization period of the adjacent battery voltage of the battery voltage.
7. The circuit of claim 1, wherein the control module further determines an equalization pause period of the battery voltage based on sampling periods of adjacent battery voltages of the battery voltage such that the sampling periods of the adjacent battery voltages are within the equalization pause period of the battery voltage.
8. The circuit of claim 7, wherein the control module is specifically configured to: and controlling the sampling module to carry out polling sampling on each battery voltage according to the sampling period of each battery voltage between adjacent series nodes in the plurality of series nodes.
9. The circuit of claim 8, wherein the control module is specifically configured to: and controlling the sampling module to carry out polling sampling on each battery voltage according to the position sequence of the plurality of nodes connected in series.
10. The circuit of claim 9, wherein the control module is specifically configured to: when the sampling period of the last polling voltage of the current polling voltages in the respective battery voltages arrives, control starts an equalization suspension period of the current polling voltage, and when the sampling period of the next polling voltage of the current polling voltage ends, control ends the equalization suspension period of the current polling voltage.
11. A battery pack, comprising:
battery module, and battery management system according to any one of claims 1 to 10.
CN202311118332.5A 2023-08-31 2023-08-31 Battery management system and battery pack Pending CN117134460A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311118332.5A CN117134460A (en) 2023-08-31 2023-08-31 Battery management system and battery pack

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311118332.5A CN117134460A (en) 2023-08-31 2023-08-31 Battery management system and battery pack

Publications (1)

Publication Number Publication Date
CN117134460A true CN117134460A (en) 2023-11-28

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Family Applications (1)

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Country Status (1)

Country Link
CN (1) CN117134460A (en)

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