Patent Application
20250239866
The present invention relates to a battery system and a control method thereof, and more particularly, to a battery system, a battery control device, and a control method of a battery system for sequentially charging batteries having different voltages.
A secondary battery is a battery that can be reused through charging even after being discharged, can be used as an energy source for a small device such as a mobile phone, a tablet PC and a vacuum cleaner, and is also used as an energy source for mid-size and large-size devices such as an automobile and an ESS (Energy Storage System) for a smart grid.
The secondary battery is applied to a system in a form of an assembly such as a battery module in which a plurality of battery cells are connected in series and parallel or a battery pack in which battery modules are connected in series and parallel, depending on system requirements. In the case of mid-size and large-size devices such as an electric vehicle, a high-capacity battery system in which a plurality of battery packs are connected in parallel may be applied so as to satisfy a required capacity of the corresponding device.
In the high-capacity battery system in which the plurality of battery packs are configured as such, when a new battery pack is additionally installed to expand a capacity or when an abnormality occurs in some of the battery packs, high voltage differences may occur among the battery packs. At this time, when the battery packs are charged using a general charging method, charging efficiency may be lowered, a battery lifetime may be reduced, and some components of the battery system may be damaged.
Accordingly, there is a need for an appropriate control technique for charging battery packs exhibiting high voltage differences.
The present invention has been made in an effort to provide a battery system for sequentially charging batteries.
The present invention has also been made in an effort to provide a control method of the battery system.
The present invention has also been made in an effort to provide a battery control device for controlling an operation of the battery system.
An exemplary embodiment of the present invention provides a battery system including a battery control device including at least one processor and memory. The battery system may further include a plurality of battery packs.
The battery control device may be configured to collect voltage values for each battery pack of a plurality of battery packs, control charging of the plurality of battery packs, based on the collected voltage values, determine a charging group by selecting one or more battery packs having a voltage value within a predefined threshold range, and to control the battery packs included in the charging group to be charged together up to a predefined target voltage. Here, the battery control device may be configured, upon the battery packs included in the charging group being charged up to the target voltage, to update the battery packs included in the charging group by selecting, from among battery packs in which charging is not in progress, a battery pack whose voltage value is within a predefined threshold range from the predefined target voltage.
The battery control device may be configured to determine a first battery pack having the lowest voltage value from among the plurality of battery packs, to select a second battery pack for which a voltage value difference between the second battery pack and the first battery pack is equal to or less than a preset first threshold value, and to determine the charging group to include the first and second battery packs.
The battery control device may be configured, upon the first and second battery packs being charged up to the predetermined target voltage, update the charging group by selecting, from among the battery packs in which charging is not in progress, a third battery pack whose voltage value is equal to or greater than the predefined target voltage by a preset second threshold value or less, and adding the selected third battery pack to the charging group, and control the battery packs included in the charging group to be charged together up to a second target voltage.
The battery control device may be configured to select, from among the battery packs in which charging is not in progress, a fourth battery pack whose voltage value is less than the second target voltage by a preset third threshold value or less and to add the selected fourth battery pack to the charging group.
The third threshold value may be based on at least one of (i) a measurement error range of a voltage measurement device configured to measure a voltage value of a battery pack or (ii) a data processing speed of the battery control device.
The third threshold value may be equal to or greater than a maximum measurement error value of the voltage measurement device and equal to or less than the second threshold value.
The third threshold may be equal to or greater than a maximum value of a rising voltage during data processing time for updating the charging group and equal to or less than the second threshold value.
Another exemplary embodiment of the present invention provides a control method of a battery system including a plurality of battery packs, and a battery control device, the control method including collecting, by the battery control device, voltage values for each of the plurality of battery packs; determining, by the battery control device, a charging group by selecting one or more battery packs having a voltage value within a predefined threshold range; controlling, by the battery control device, the battery packs included in the charging group to be charged together up to a predefined target voltage; and upon the battery packs included in the charging group being charged up to the target voltage, updating, by the battery control device, charging group by selecting, from among the battery packs for which charging is not in progress, a battery pack whose voltage value is within a predefined threshold range from the predefined target voltage.
Determining the charging group may include determining a first battery pack having the lowest voltage value from among the plurality of battery packs; selecting a second battery pack for which a voltage value difference between the second battery pack and the first battery pack is equal to or less than a preset first threshold value; and determining the charging group to include the first and second battery packs.
The method may include upon the first and second battery packs being charged up to the predetermined target voltage, selecting, from among the battery packs in which charging is not in progress, a third battery pack whose voltage value is equal to or greater than the predefined target voltage by a preset second threshold value or less; adding the selected third battery pack to the charging group; and controlling the battery packs included in the charging group to be charged together up to a second target voltage.
The method may include selecting, from among the battery packs in which charging is not in progress, a fourth battery pack whose voltage value is less than the second target voltage by a preset third threshold value or less; and adding the selected fourth battery pack to the charging group.
The third threshold value may be equal to or greater than a maximum measurement error value of a voltage measurement device and equal to or less than the second threshold value.
The third threshold may be equal to or greater than a maximum value of a rising voltage during data processing time for updating the charging group and equal to or less than the second threshold value.
Still another exemplary embodiment of the present invention provides a battery control device located in a battery system including a plurality of battery packs, the control device including at least one processor; and a memory storingcommands that are configured to be executed by the at least one processor.
Here, commands may be executed by the at least one processor to collect voltage values for each of the plurality of battery packs; determine a charging group by selecting one or more battery packs having a voltage value within a predefined threshold range; control battery packs included in the charging group to be charged together to a predefined target voltage; and upon the battery packs included in the charging group being charged up to the target voltage, update the charging group by selecting, from among the battery packs for which charging is not in progress, a battery pack whose voltage value is within a predefined threshold range from the predefined target voltage.
The commands may be executed by the at least one processor to determine a first battery pack having the lowest voltage value from among the plurality of battery packs; select a second battery pack voltage value difference between the second battery pack and the first battery pack is equal to or less than a preset first threshold value; and determine the charging group to include the first and second battery packs.
The commands may be executed by the at least one processor to upon the first and second battery packs being charged up to the predetermined target voltage, select, from among the battery packs in which charging is not in progress, a third battery pack whose voltage value is equal to or greater than the predefined target voltage by a preset second threshold value or less; and a command to add the selected third battery pack to the charging group, and control the battery packs included in the charging group to be charged together up to a second target voltage.
The commands may be executed by the at least one processor to select, from among the battery packs in which charging is not in progress, a fourth battery pack whose voltage value is less than the second target voltage by a preset third threshold value or less; and a command to add the selected fourth battery pack to the charging group.
The third threshold value may be equal to or greater than a maximum measurement error value of a voltage measurement device and equal to or less than the second threshold value.
The third threshold may be equal to or greater than a maximum value of a rising voltage during data processing time for updating the charging group and equal to or less than the second threshold value.
According to exemplary embodiments of the present invention, it is possible to effectively charge the battery packs exhibiting high voltage differences by grouping and sequentially charging battery packs having a voltage value within a certain range.
The present invention may be modified in various forms and have various embodiments, and specific embodiments thereof are shown by way of example in the drawings and will be described in detail below. It should be understood, however, that there is no intent to limit the present invention to the specific embodiments, but on the contrary, the present invention is to cover all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Like reference numerals refer to like elements throughout the description of the figures.
It will be understood that, although the terms such as first, second, A, B, and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term “and/or” includes combinations of a plurality of associated listed items or any of the plurality of associated listed items.
It will be understood that when an element is referred to as being “coupled” or “connected” to another element, it can be directly coupled or connected to the other element or an intervening element may be present. In contrast, when an element is referred to as being “directly coupled” or “directly connected” to another element, there is no intervening element present.
The terms used herein is for the purpose of describing specific embodiments only and are not intended to limit the present invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes”, “including” and/or “having”, when used herein, specify the presence of stated features, integers, steps, operations, constitutional elements, components and/or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, constitutional elements, components, and/or combinations thereof.
Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meanings as commonly understood by one skilled in the art to which the present invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having meanings that are consistent with their meanings in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Some terms used herein are defined as follows.
A battery cell is a minimum unit that serves to store power, and a battery module refers to an assembly in which a plurality of battery cells are electrically connected.
A battery pack or battery rack refers to a system with a minimum single structure can be monitored and controlled through a battery management system (BMS) by electrically connecting module units set by a battery manufacturer, and may include several battery modules and one battery protection unit (BPU) or protection device.
A battery bank may refer to an assembly group of large-scale battery rack systems configured by connecting a plurality of battery racks in parallel. Monitoring and control of a rack BMS (RBMS) of a battery rack unit can be performed through the BMS of a battery bank unit.
A battery assembly includes a plurality of electrically connected battery cells, and refers to an assembly that functions as a power supply source by being applied to a specific system or device. Here, the battery assembly may mean a battery module, a battery pack, a battery rack, a battery bank or the like, but the scope of the present invention is not limited to these entities.
A state of charge (SOC) is a current charged state of a battery expressed as a percentage [%], and a state of health (SOH) is a current remaining state of a battery expressed as a percentage [%].
A nominal capacity (nominal capa.) may mean a set capacity [Ah] of a battery set by a battery manufacturer during development.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
Referring to
The plurality of battery packs 100 may be connected to each other in parallel to constitute a battery assembly.
The battery system according to an embodiment of the present invention may be included and implemented in an electric vehicle, but the scope of the present invention is not limited to the entity. That is, the battery system according to an embodiment of the present invention may be applied to a device having a plurality of battery packs and may be configured to control charging of the battery packs exhibiting voltage differences through a control operation described below.
The battery control device 200 may be included and implemented in a BMS located inside the battery system.
The battery control device 200 may be configured to collect voltage values for each of the plurality of battery packs 100 and to control charging of the plurality of battery packs, based on the collected voltage values. Here, the battery control device 200 may be configured to control charging of each battery pack in a manner of controlling a charging circuit connected to each of the plurality of battery packs 100 (for example, ON/OFF control of a relay circuit).
Hereinafter, operations of the battery system and the battery control device 200 according to an embodiment of the present invention will be described in detail with reference to
The battery control device 200 collects voltage values for each of a plurality of battery packs. Here, the battery control device 200 may collect the voltage values of the battery packs for each preset unit time (for example, 1 second) or predefined time point (for example, determination or update time point of a charging group).
The battery control device 200 determines a charging group including some of the plurality of battery packs, based on the voltage values for each of the plurality of battery packs (S210).
Here, the battery control device 200 may select one or more battery packs having a voltage value within a predefined threshold range and determine the selected battery packs as a charging group. Meanwhile, when the selected battery pack is a battery pack determined as being in an abnormal state, the battery pack in the abnormal state may be excluded from the charging group.
Thereafter, the battery control device 200 controls the battery packs included in the charging group determined in S210 to be charged together up to a predefined target voltage (S220). Here, the target voltage may be defined as the lowest value among the voltage values of the respective battery packs not included in the charging group.
When the battery packs included in the charging group are charged up to the target voltage, the battery control device 200 checks whether charging of all the battery packs is completed (S230).
When all the battery packs are not completely charged (NO in S230), the battery control device 200 updates the charging group determined in S210 and the target voltage (S240).
Here, the battery control device 200 may update the charging group by selecting a battery pack whose voltage value is within a predefined threshold range from a voltage value of the charging group among battery packs in which charging is not in progress (i.e., battery packs not included in the charging group) and including the selected battery pack in the charging group. Meanwhile, when the selected battery pack is a battery pack determined as being in an abnormal state, the battery pack in the abnormal state may be excluded from the charging group. In addition, the battery control device 200 may update the currently set target voltage to the lowest value among the voltage values of the respective battery packs not included in the updated charging group.
Thereafter, the battery control device 200 controls the battery packs included in the updated charging group to be charged together up to the updated target voltage (S220).
As shown in
The battery packs included in the battery system shown in
The battery control device 200 determines a first battery pack having the lowest voltage value among the plurality of battery packs. Also, the battery control device 200 selects a second battery pack whose voltage value difference from that of the first battery pack is equal to or less than a preset first threshold value. Thereafter, the battery control device 200 determines the first and second battery packs as a charging group.
For example, referring to
The battery control device 200 controls the battery packs included in the charging group to be charged together up to a predefined target voltage. Here, the target voltage may be defined as the lowest value among the voltage values of the respective battery packs not included in the charging group.
For example, referring to
On the other hand, even when the battery pack is charged up to the set target voltage, the voltage of the battery pack may not reach the target voltage because the target voltage is a maximum voltage of a battery cell included in the battery pack. For example, as shown in
When the charging group is charged up to the target voltage, the battery control device 200 selects, among battery packs in which charging is not in progress, a third battery pack whose voltage value is equal to or greater than the voltage value of the charging group and voltage value difference from that of the charging group is equal to or less than a preset second threshold value. Thereafter, the battery control device 200 updates the charging group by adding the selected third battery pack to the charging group. Also, the battery control device 200 updates the currently set target voltage to the lowest value among the voltage values of the respective battery packs not included in the updated charging group.
For example, when the second threshold value is defined as 10V, as shown in
The battery control device 200 controls the battery packs included in the updated charging group to be charged together up to the updated target voltage.
For example, referring to
After completion of the charging up to the target voltage, the battery control device 200 determines the battery packs #5 and #6 exhibiting voltage values of 348V or higher and 358V or lower among the battery packs #5 and #6, as the third battery pack, and updates the charging group (battery packs #1 to #6) by including the battery packs #5 and #6 in the charging group.
When there is no battery pack not included in the updated charging group, the battery control device 200 may update the currently set target voltage to the highest value among the voltage values of the respective battery packs included in the updated charging group. For example, the battery control device 200 may update the currently set target voltage (350V) to 355V, which is the highest value among the voltage values of the battery packs #1 to #6 included in the updated charging group.
When the charging up to the updated target voltage (355V) is completed, the charging of all the battery packs is completed, and therefore, the charging process ends.
The battery control device 200 according to an embodiment of the present invention determines or updates a charging group, based on measured voltages value of battery packs. Here, when the measurement accuracy of a voltage measurement device is low or when a data processing speed of the system is slow, a problem that some of the battery packs to be included in the charging group are missed may occur.
For example, in
Here, when the voltage measurement device has a certain measurement error range (for example, −4V to +4V), the voltage values of the battery packs #1 and #2 may be measured as 321V although the actual voltage values of the battery packs #1 and #2 are 318V. In this case, the battery control device 200 may add the battery pack #4 exhibiting a voltage value of 321V or higher and 331V or lower among the battery packs #3 to #6 to the charging group, and the battery pack #3 that should be included in the charging group may be missed.
Also, when the battery system is implemented as a low-performance system, the charging group update process may be delayed after the charging of the battery packs #1 and #2 is completed. In this case, during the data processing time for updating the charging group, the voltages of the battery packs #1 and #2 may be increased to 319V by the minute charging current. In this case, the battery control device 200 may add the battery pack #4 exhibiting a voltage value of 319V or higher and 329V or lower among the battery packs #3 to #6 to the charging group, and the battery pack #3 that should be included in the charging group may be missed.
When updating the charging group, the battery control device 200 may perform an operation according to an embodiment below so that a battery pack to be included in the charging group is not missed due to the measurement performance of the voltage measurement device and the data processing speed of the battery system.
When the charging group is charged up to the target voltage, the battery control device 200 selects, among battery packs in which charging is not in progress, a fourth battery pack whose voltage value is less than the voltage value of the charging group and voltage value difference from that of the charging group is equal to or less than a preset third threshold value. Thereafter, the battery control device 200 adds the selected fourth battery pack to the charging group.
For example, in
The third threshold value may be defined based on at least one of a measurement error range of the voltage measurement device and a data processing speed of the battery control device.
In an embodiment, the third threshold value may be defined as a value equal to or greater than a maximum measurement error value of the voltage measurement device and equal to or less than the second threshold value. For example, when the second threshold value is 10V and the measurement error range of the voltage measurement device is −4 V to +4 V, the third threshold value may be defined as a value equal to or greater than 4 and equal to or less than 10.
In another embodiment, the third threshold value may be defined as a value equal to or greater than a maximum value of a rising voltage during data processing time for updating the charging group and equal to or less than the second threshold value. Here, the maximum value of the rising voltage may be defined through a pre-test for the charging group update process. For example, when the second threshold value is 10V and the maximum value of the rising voltage during the data processing time for updating the charging group is 1V, the third threshold value may be defined as a value equal to or greater than 1 and equal to or less than 10.
A battery control device 600 according to an embodiment of the present invention is located in a battery system including a plurality of battery packs, and may include at least one processor 610, a memory 620 configured to store at least one command that is executed through the processor, and a transmitting/receiving device 630 connected to a network and configured to perform communication.
The at least one command may include a command to collect voltage values for each of the plurality of battery packs; a command to determine a charging group by selecting one or more battery packs having a voltage value within a predefined threshold range; a command to control battery packs included in the charging group to be charged together to a predefined target voltage; and a command, when charging up to the target voltage is completed, to update the charging group by selecting, among battery packs in which charging is not in progress, a battery pack whose voltage value is within a predefined threshold range from a voltage value of the charging group.
The command to determine the charging group may include a command to determine a first battery pack having the lowest voltage value among the plurality of battery packs; a command to select a second battery pack whose voltage value difference from that of the first battery pack is equal to or less than a preset first threshold value; and a command to determine the first and second battery packs as the charging group.
The command to update the charging group may include a command to select, among the battery packs in which charging is not in progress, a third battery pack whose voltage value is equal to or greater than the voltage value of the charging group and voltage value difference from that of the charging group is equal to or less than a preset second threshold value; and a command to add the selected third battery pack to the charging group.
The command to update the charging group may include a command to select, among the battery packs in which charging is not in progress, a fourth battery pack whose voltage value is less than the voltage value of the charging group and voltage value difference from that of the charging group is equal to or less than a preset third threshold value; and a command to add the selected fourth battery pack to the charging group.
The third threshold value may be defined as a value equal to or greater than a maximum measurement error value of the voltage measurement device and equal to or less than the second threshold value.
The third threshold value may be defined as a value equal to or greater than a maximum value of a rising voltage during data processing time for updating the charging group and equal to or less than the second threshold value.
The battery control device 600 may further include an input interface device 640, an output interface device 650, a storage device 660, and the like. The respective components included in the battery control device 600 may be connected by a bus 670 and configured to perform communication with each other.
Here, the processor 610 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. The memory (or storage device) may be configured by at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory may be configured by at least one of a read only memory (ROM) and a random access memory (RAM).
Operations according to embodiments of the present invention can be embodied as a computer-readable program or code on a computer-readable recording medium. The computer-readable recording medium includes all types of recording media in which data readable by a computer system is stored. In addition, the computer-readable recording medium may be distributed over computer systems connected through a network so that a computer-readable program or code may be stored and executed in a distributed manner.
Some aspects of the present invention have been described above in the context of a device but may be described using a method corresponding thereto. Here, blocks or the device corresponds to operations of the method or characteristics of the operations of the method. Similarly, aspects of the present invention described above in the context of a method may be described using blocks or items corresponding thereto or characteristics of a device corresponding thereto. Some or all of the operations of the method may be performed, for example, by (or using) hardware device such as a microprocessor, a programmable computer or an electronic circuit. In some embodiments, one or more of most important operations of the method may be performed by such a device.
While the present invention has been described above with reference to embodiments thereof, it would be understood by one skilled in the art that various changes and modifications can be made in the present invention without departing from the spirit and scope of the present invention defined in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0082964 | Jul 2022 | KR | national |
The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2023/008702, filed on Jun. 22, 2023, now published as International Publication No. WO 2024/010254, which claims priority from Korean Patent Application No. 10-2022-0082964, filed on Jul. 6, 2022, all of which are hereby incorporated herein by reference in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/008702 | 6/22/2023 | WO |
