KR20230046147A - Battery control system and method of the same - Google Patents

Abstract

According to the present document, a battery control system comprises: a plurality of battery cells connected in series; a plurality of switches arranged to activate or deactivate each of the plurality of battery cells; and a battery management system connected to the plurality of switches. The battery management system can be set to measure a voltage or SOC of each of the plurality of battery cells, check a voltage or SOC deviation between the plurality of battery cells, and control at least one of the plurality of switches to deactivate the battery cells whose deviation is greater than or equal to a threshold value if the number of battery cells whose deviation is greater than or equal to the threshold value is less than a threshold number.

Description

Battery control system and method {BATTERY CONTROL SYSTEM AND METHOD OF THE SAME}

Embodiments disclosed herein relate to a battery control system and method.

Recently, research and development on secondary batteries have been actively conducted. Here, the secondary battery is a battery that can be charged and discharged, and means to include all of the conventional Ni/Cd batteries, Ni/MH batteries, and recent lithium ion batteries. Among secondary batteries, lithium ion batteries have the advantage of much higher energy density than conventional Ni/Cd batteries and Ni/MH batteries. In addition, lithium ion batteries can be manufactured in a small size and light weight, so they are used as a power source for mobile devices. . In addition, the lithium ion battery has been attracting attention as a next-generation energy storage medium as its use range has been expanded as a power source for electric vehicles.

In a battery pack composed of a plurality of battery cells, if voltages between battery cells connected in series are uneven, a safety problem may occur, so cell balancing may be performed to make the voltages even. For example, the battery management system can match the voltage of a cell with a high voltage to a level similar to that of a cell with a low voltage through a voltage drop through a resistor. However, since such cell balancing lowers the voltage based on a cell having a low voltage, unnecessary energy consumption is caused and cell deterioration is accelerated.

Technical problems of the embodiments disclosed in this document are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the description below.

A battery control system disclosed in this document includes a plurality of battery cells connected in series, a plurality of switches arranged to activate or deactivate each of the plurality of battery cells, and a battery management system connected to the plurality of switches, The battery management system measures the voltage or SOC of each of the plurality of battery cells, checks the voltage or SOC deviation between the plurality of battery cells, and if the number of battery cells having a deviation greater than or equal to a threshold value is less than the threshold number, It may be configured to control at least one of the plurality of switches so that a battery cell having the deviation equal to or greater than the threshold value is deactivated.

A method of operating a battery control system disclosed in this document includes an operation of measuring a voltage or SOC of each of a plurality of battery cells, an operation of checking a voltage or SOC deviation between the plurality of battery cells, and a battery cell having a deviation greater than or equal to a threshold value. When the number is less than the threshold, controlling at least one of a plurality of switches to deactivate a battery cell having a deviation equal to or greater than the threshold may be performed.

The battery control system according to an embodiment disclosed in this document can prevent unnecessary energy consumption and accelerated deterioration of cells caused by cell balancing.

The battery control system according to an embodiment disclosed in this document can reduce task consumption of the battery management system caused by cell balancing.

1 is a block diagram illustrating the configuration of a general battery pack including a battery management device according to various embodiments.
2 is a block diagram illustrating the configuration of a battery control system according to various embodiments.
3 illustrates an operational flow diagram of controlling a switch according to various embodiments.
4 shows an operational flow diagram of controlling a switch according to various embodiments.
5 illustrates an operational flow diagram of controlling a switch according to various embodiments.
6 is a block diagram illustrating a computing system executing a battery management method according to various embodiments.

Hereinafter, various embodiments disclosed in this document will be described in detail with reference to the accompanying drawings. In this document, the same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

For various embodiments disclosed in this document, specific structural or functional descriptions are merely illustrated for the purpose of describing the embodiments, and various embodiments disclosed in this document may be implemented in various forms, and It should not be construed as limited to the described embodiments.

Expressions such as "first", "second", "first", or "second" used in various embodiments may modify various elements regardless of order and/or importance, and the elements Not limited. For example, a first component may be called a second component without departing from the scope of rights of the embodiments disclosed in this document, and similarly, the second component may also be renamed to the first component.

Terms used in this document are only used to describe a specific embodiment, and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly dictates otherwise.

All terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by a person of ordinary skill in the art of the embodiments disclosed in this document. Terms defined in commonly used dictionaries may be interpreted as having the same or similar meanings as those in the context of the related art, and unless explicitly defined in this document, they are not interpreted in ideal or excessively formal meanings. . In some cases, even terms defined in this document cannot be interpreted to exclude the embodiments disclosed in this document.

1 is a block diagram illustrating the configuration of a general battery pack including a battery management device according to various embodiments.

Specifically, FIG. 1 schematically shows a battery control system 1 including a battery pack 10 according to an embodiment disclosed in this document and a host controller 20 included in a host system.

As shown in FIG. 1 , the battery pack 10 may include a plurality of battery modules 12 , a sensor 14 , a switching unit 16 , and a battery management system 100 . In this case, the battery pack 10 may include a plurality of battery modules 12 , sensors 14 , switching units 16 , and battery management systems 100 .

The plurality of battery modules 12 may include at least one battery cell capable of charging and discharging. At this time, the plurality of battery modules 12 may be connected in series or parallel.

The sensor 14 may detect current flowing through the battery pack 10 . At this time, the detection signal may be transmitted to the battery management system 100 .

The switching unit 16 is serially connected to the (+) terminal side or the (-) terminal side of the battery module 12 to control the flow of charging/discharging current of the battery module 12 . For example, at least one relay or magnetic contactor may be used as the switching unit 16 according to specifications of the battery pack 10 .

The battery management system 100 may monitor the voltage, current, temperature, etc. of the battery pack 10 and control and manage to prevent overcharge and overdischarge, and may include, for example, RBMS.

The battery management system 100 is an interface for receiving measured values of various parameters described above, and may include a plurality of terminals and a circuit connected to the terminals to process the input values. In addition, the battery management system 100 may control ON/OFF of the switching unit 16, for example, a relay or a contactor, and is connected to the battery module 12 to monitor each state of the battery module 12. can be monitored

The upper controller 20 may transmit a control signal for controlling the battery module 12 to the battery management system 100 . Accordingly, the operation of the battery management system 100 may be controlled based on the control signal applied from the upper controller 20 . In addition, the battery module 12 may be a component included in an energy storage system (ESS). In this case, the upper controller 20 may be a battery bank controller (BBMS) including a plurality of battery packs 10 or an ESS controller that controls the entire ESS including a plurality of banks. However, the battery pack 10 is not limited to this purpose.

2 is a block diagram illustrating the configuration of a battery control system according to various embodiments.

Referring to FIG. 2, the battery control system 1 activates or Switches 220-1, 220-2, ... arranged to be inactive may be included. The external device 230 may be a device receiving voltage from a plurality of battery cells. For example, the external device 230 may be the configuration shown in FIG. 1 or a device used to drive a vehicle. Although not shown in FIG. 2 , each of the plurality of battery cells and the plurality of switches may be connected to the battery management system 100 and controlled by the battery management system 100 .

In an embodiment, the battery management system 100 does not perform cell balancing when the number of battery cells having a low voltage or SOC is small, unlike the conventional method in which cell balancing is performed based on battery cells having a low voltage or SOC, thereby avoiding unnecessary cell balancing. Energy consumption and accelerated deterioration of cells can be prevented. In this case, the battery management system 100 may deactivate a battery cell having a low voltage or SOC by using a switch. For example, the battery management system 100 may control the switch 220-2 to activate the battery cell 210-1 through the switch 220-1 while inactivating the battery cell 210-2. can At this time, the battery management system 100 may activate all the battery cells when a voltage or SOC deviation between the battery cells is small.

The battery management system 100 according to the embodiment may normally maintain the voltage provided by the battery pack to the external device 230 by limiting the number of deactivated battery cells to a certain level. For example, the battery management system 100 may control inactivation through switching only when the number of battery cells having a low voltage or low SOC is less than a predetermined ratio (eg, 25%) of the total number of battery cells.

The battery management system 100 according to the embodiment can prevent errors in consistency check and battery management IC (BMIC) communication by excluding inactive battery cells from a battery diagnosis process. For example, when determining the matching of the sum of the voltages of the battery cells and the voltage of the battery pack, the battery management system 100 determines the sum of the cell voltages excluding the voltages of the inactive battery cells (eg, 210-2). can be calculated

3 illustrates an operational flow diagram of controlling a switch according to various embodiments. Operations described below may be implemented by the battery control system 1 or by its components (eg, the battery management system 100).

Referring to FIG. 3 , in operation 310, the battery management system 100 may measure a voltage or SOC of each of a plurality of battery cells.

In operation 320, the battery management system 100 may check a voltage or SOC deviation between cells. Here, the deviation may mean a difference between the maximum voltage of the plurality of battery cells and each individual voltage. Also, the deviation may mean a difference between a maximum SOC of a plurality of battery cells and each individual SOC. For example, the voltage deviation may be referred to as a voltage (V) unit, and the SOC deviation may be referred to as a % unit.

In operation 330, when the number of battery cells having a deviation greater than or equal to a threshold value is less than the threshold number, the battery management system 100 may control a switch to deactivate a corresponding battery cell (ie, a battery cell having a deviation greater than or equal to the threshold value). The case where the deviation is greater than or equal to a threshold value may mean, for example, a case in which a voltage difference from the maximum voltage is greater than or equal to a threshold value (eg, 0.5V). In this case, the corresponding battery cell may be deactivated by a switch. Similarly, a battery cell having an SOC difference greater than or equal to a threshold value (eg, 10%) from the maximum SOC may be deactivated by a switch.

In an embodiment, if the number of battery cells having a deviation greater than or equal to the threshold is greater than or equal to the threshold, the battery management system 100 may maintain the current state without controlling the switch even if there are battery cells having a deviation greater than or equal to the threshold.

4 shows an operational flow diagram of controlling a switch according to various embodiments.

Referring to FIG. 4 , in operation 410, the battery management system 100 may measure a voltage or SOC of each of a plurality of battery cells.

In operation 420, the battery management system 100 may check whether the minimum SOC exceeds a first threshold SOC. The first threshold SOC may be an SOC that requires charging of the battery pack or battery diagnosis. For example, the first threshold SOC may be 30%.

When the minimum SOC is equal to or less than the first threshold SOC, the battery management system 100 may charge the battery or output an alarm for battery diagnosis in operation 430 . When performing the battery diagnosis, the battery management system 100 may perform a consistency check on the sum of the voltages of the battery cells and the voltages of the battery pack, excluding battery cells that have already been deactivated through a switch. Thereafter, the battery management system 100 may repeat operations 410 and 420 .

If the minimum SOC exceeds the first threshold SOC, in operation 440, the battery management system 100 may control the switch based on the voltage between cells or the SOC deviation (eg, operations 320 to 330 of FIG. 3).

5 illustrates an operational flow diagram of controlling a switch according to various embodiments. The operations illustrated in FIG. 5 may be, for example, an embodiment of operation 440 of FIG. 4 .

Referring to FIG. 5 , in operation 510, the battery management system 100 may check whether the minimum SOC exceeds the second threshold SOC. The second threshold SOC is a value for adjusting the number of thresholds and may be greater than the first threshold SOC. For example, the second threshold SOC may be 90%. The battery management system 100 can minimize the influence of the voltage provided by the battery pack on the external device 230 even if some battery cells are deactivated by adjusting the threshold number according to the minimum SOC.

In an embodiment, if the minimum SOC is greater than the second threshold SOC, the battery management system 100 sets the threshold number to a first ratio of battery cells (operation 520), and if the minimum SOC is less than or equal to the second threshold SOC, the battery management system 100 sets the threshold number to a first ratio of battery cells (operation 520). The management system 100 may set the threshold number to a second ratio smaller than the first ratio. For example, if the second threshold SOC is 90% and the total number of battery cells is 12, the battery management system sets the threshold number when the minimum SOC exceeds (or exceeds) 90% to 3, which is 25% of all battery cells. In general, when the minimum SOC is 90% or less (or less), the threshold number may be set to 2, which is about 15% of all battery cells.

In operation 540, the battery management system 100 may check whether the number of battery cells having a deviation greater than or equal to a threshold value is less than the threshold number. If the number of battery cells having a deviation greater than or equal to the threshold is less than the threshold number, in operation 550, the battery management system 100 may control a switch to inactivate battery cells having a deviation greater than or equal to the threshold. When the number of battery cells having a deviation greater than or equal to the threshold value is greater than or equal to the threshold number, the battery management system 100 may maintain the current switch state in operation 560 .

6 is a block diagram illustrating a computing system executing a battery management method according to various embodiments.

Referring to FIG. 6 , a computing system 30 according to an embodiment disclosed in this document may include an MCU 32, a memory 34, an input/output I/F 36, and a communication I/F 38. there is.

The MCU 32 executes various programs stored in the memory 34 (eg, a characteristic value calculation program, a class classification and life estimation program, etc.), and through these programs, the battery cell voltage, current, etc. It may be a processor that processes various data and performs functions of the battery management device shown in FIG. 2 described above.

The memory 34 may store various programs related to calculating characteristic values of battery cells, classifying them, and estimating lifespan. In addition, the memory 34 may store various data such as voltage, current, and characteristic value data of each battery cell.

A plurality of such memories 34 may be provided as needed. Memory 34 may be volatile memory or non-volatile memory. As the memory 34 as a volatile memory, RAM, DRAM, SRAM, or the like may be used. As the memory 34 as a non-volatile memory, ROM, PROM, EAROM, EPROM, EEPROM, flash memory, etc. may be used. Examples of the memories 34 listed above are merely examples and are not limited to these examples.

The input/output I/F 36 is an interface that connects an input device (not shown) such as a keyboard, mouse, or touch panel and an output device such as a display (not shown) and the MCU 32 to transmit and receive data. can provide.

The communication I/F 340 is a component capable of transmitting and receiving various data to and from the server, and may be various devices capable of supporting wired or wireless communication. For example, it is possible to transmit/receive programs or various data for calculation of characteristic values of battery cells, class classification, and life estimation from a separately provided external server through the communication I/F 38.

As such, the computer program according to an embodiment disclosed in this document is recorded in the memory 34 and processed by the MCU 32, for example, as a module that performs each function shown in FIG. 1 or 2. may be implemented.

In the above, even if all components constituting the embodiments disclosed in this document have been described as being combined or operated as one, the embodiments disclosed in this document are not necessarily limited to these embodiments. That is, within the scope of the objectives of the embodiments disclosed in this document, all of the components may be selectively combined with one or more to operate.

In addition, terms such as "comprise", "comprise" or "having" described above mean that the corresponding component may be present unless otherwise stated, and thus exclude other components. It should be construed as being able to further include other components. All terms, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments disclosed in this document belong, unless defined otherwise. Commonly used terms, such as terms defined in a dictionary, should be interpreted as consistent with the contextual meaning of the related art, and unless explicitly defined in this document, they are not interpreted in an ideal or excessively formal meaning.

The above description is only an illustrative example of the technical idea disclosed in this document, and those skilled in the art to which the embodiments disclosed in this document belong will be within the scope of the essential characteristics of the embodiments disclosed in this document. Many modifications and variations will be possible. Therefore, the embodiments disclosed in this document are not intended to limit the technical spirit of the embodiments disclosed in this document, but to explain, and the scope of the technical spirit disclosed in this document is not limited by these embodiments. The scope of protection of technical ideas disclosed in this document should be interpreted according to the scope of claims below, and all technical ideas within an equivalent scope should be construed as being included in the scope of rights of this document.

Claims (10)

In the battery control system,
A plurality of battery cells connected in series;
a plurality of switches arranged to activate or deactivate each of the plurality of battery cells; and
Including; a battery management system connected to the plurality of switches, wherein the battery management system,
Measuring the voltage or state of charge (SOC) of each of the plurality of battery cells;
Checking the voltage or SOC deviation between the plurality of battery cells, and
and controlling at least one of the plurality of switches so that the battery cells having a deviation greater than or equal to the threshold are deactivated when the number of battery cells having a deviation greater than or equal to the threshold is less than the threshold number. The method according to claim 1, wherein the battery management system,
When the minimum SOC of the plurality of battery cells is less than or equal to a first threshold SOC, charging the battery or outputting an alarm for battery diagnosis;
A battery control system configured to control at least one of the plurality of switches when the minimum SOC is greater than the first threshold SOC. The method according to claim 2, wherein the battery management system,
If the minimum SOC is greater than the first threshold SOC, check whether the minimum SOC exceeds a second threshold SOC greater than the first threshold SOC;
When the minimum SOC is greater than the second threshold SOC, setting the threshold number to a first ratio of the plurality of battery cells;
and setting the threshold number to a second ratio smaller than the first ratio when the minimum SOC is less than or equal to the second threshold SOC. The method according to claim 1, wherein the battery management system,
If the number of battery cells having the deviation equal to or greater than the threshold value is equal to or greater than the threshold coefficient, the current switch state is maintained. The method according to claim 1, wherein the battery management system,
A battery control system configured to perform battery diagnosis except for the deactivated battery cell during battery diagnosis. In the operating method of the battery control system,
measuring a voltage or state of charge (SOC) of each of the plurality of battery cells;
checking a voltage or SOC deviation between the plurality of battery cells; and
and controlling at least one of a plurality of switches so that battery cells having a deviation greater than or equal to the threshold are deactivated when the number of battery cells having a deviation greater than or equal to the threshold is less than the threshold. The method of claim 6,
If the minimum SOC of the plurality of battery cells is less than or equal to a first threshold SOC, charging the battery or outputting an alarm for battery diagnosis; further comprising, the operating method of the battery control system. The method of claim 7,
when the minimum SOC exceeds the first threshold SOC, determining whether the minimum SOC exceeds a second threshold SOC greater than the first threshold SOC;
setting the threshold number as a first ratio of the plurality of battery cells when the minimum SOC exceeds the second threshold SOC; and
and setting the threshold number to a second ratio smaller than the first ratio when the minimum SOC is less than or equal to the second threshold SOC. The method of claim 6,
and maintaining a current switch state when the number of battery cells having the deviation equal to or greater than the threshold is equal to or greater than the threshold count. The method of claim 6,
The operation of performing battery diagnosis except for the inactivated battery cell when diagnosing a battery; further comprising a method of operating a battery control system.

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