KR-20260066031-A - BATTERY MANAGEMENT SYSTEM, BATTERY PACK, ELECTRIC VEHICLE, AND BATTERY MANAGEMENT METHOD

KR20260066031AKR 20260066031 AKR20260066031 AKR 20260066031AKR-20260066031-A

Abstract

A battery management system according to the present invention comprises: a battery monitor configured to detect the voltage of each of a plurality of batteries; a balancer configured to perform balancing processing for at least one battery; and a control circuit configured to control the balancer based on the voltage of each battery detected by the battery monitor. The control circuit is configured to obtain a first voltage value including a voltage value that compensates for the no-load voltage of at least one battery that was previously balanced and a voltage value representing the no-load voltage of at least one battery that was not balanced, while the balancing processing is not being performed, determine a voltage deviation which is the difference between the first voltage value and a reference voltage value, and detect whether each battery is abnormal based on the amount of change in the voltage deviation of each battery.

Inventors

박희주
김철택
성용철

Assignees

주식회사 엘지에너지솔루션

Dates

Publication Date: 20260512
Application Date: 20260428

Claims (15)

At least one processor; and It includes a memory that stores at least one instruction executed by the above-mentioned at least one processor, and When the above at least one instruction is executed by the above at least one processor, the processor, In a state where balancing processing for multiple batteries is not being performed, the no-load voltage value of each battery is compensated based on at least one of the voltage, balancing time, balancing current, and balancing capacity of each battery, and Determining a voltage difference which is the difference between the compensated no-load voltage value and the reference voltage value of at least one of the plurality of batteries, and A battery management system that detects whether there is an abnormality in at least one battery based on the amount of change in the voltage difference of at least one battery.
In paragraph 1, The above processor is, If the amount of change in the voltage difference of the at least one battery is greater than or equal to a threshold value, the failure count of the at least one battery is increased by 1, and A battery management system configured to detect that at least one battery has an internal short-circuit failure when the failure count of at least one battery is greater than or equal to a predetermined value.
In paragraph 1, The above reference voltage value is, A battery management system that is the average or median value of the compensated no-load voltage values of at least two of the plurality of batteries.
In paragraph 1, The above processor is, A battery management system configured to determine the balancing capacity of each battery cell by accumulating the discharge capacity of each battery cell by each balancing process executed within a period of reference time.
In paragraph 4, A battery management system in which the above balancing capacity is obtained by the above balancing process executed during a reference time longer than the time for performing the above balancing process.
In paragraph 4, The above processor is, Based on first balancing data associated with each balancing process, the discharge capacity of each battery by each balancing process is determined, wherein The above first balancing data is a battery management system including the no-load voltage value of each battery at the start of the balancing process and the duration of the balancing process.
In paragraph 4, The above processor is, It is configured to determine the discharge capacity of each battery by each balancing process based on the second balancing data of each balancing process, The above second balancing data is a battery management system including a no-load voltage value of each battery at the start of the balancing process and a no-load voltage value of each battery at the end of the balancing process.
In paragraph 1, The above processor is, A battery management system configured to compensate the estimated SOC of each battery by adding the amount of change in SOC corresponding to the balancing capacity to the estimated SOC of each battery corresponding to the no-load voltage value of each battery, and to determine the compensated no-load voltage value based on the compensated estimated SOC of each battery.
A battery pack comprising the battery management system according to any one of claims 1 to 8.
An electric vehicle comprising the above battery pack according to paragraph 9.
A step of compensating the no-load voltage value of each battery based on at least one of the voltage, balancing time, balancing current, and balancing capacity of each battery when balancing processing for multiple batteries is not being performed; A step of determining a voltage difference which is the difference between the compensated no-load voltage value and the reference voltage value of at least one of the plurality of batteries; and A battery management method comprising the step of detecting whether the at least one battery is abnormal based on the amount of change in the voltage difference of the at least one battery.
In Paragraph 11, The step of detecting whether there is an abnormality in at least one battery is, A step of increasing the failure count of the at least one battery by 1 when the amount of change in the voltage difference of the at least one battery is greater than or equal to a threshold value; and A battery management method comprising the step of detecting that the at least one battery has an internal short-circuit failure when the failure count of the at least one battery is greater than or equal to a predetermined value.
In Paragraph 11, The above reference voltage value is, A battery management method comprising the average or median value of the compensated no-load voltage values of at least two of the plurality of batteries.
In Paragraph 11, The step of compensating the above-mentioned no-load voltage value of each battery is, A step of compensating the estimated SOC of each battery by adding the amount of change in SOC corresponding to the balancing capacity to the estimated SOC of each battery corresponding to the no-load voltage value of each battery; and A battery management method comprising the step of determining a compensated no-load voltage value based on an estimate of the compensated SOC of each battery.
A recording medium having a program recorded thereon for executing a battery management method according to any one of paragraphs 11 through 14.

Description

Battery Management System, Battery Pack, Electric Vehicle, and Battery Management Method The present invention relates to a technology for detecting internal short-circuit failures in a battery. Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly, and the development of electric vehicles, energy storage batteries, robots, and satellites has accelerated, research on high-performance batteries capable of repeated charging and discharging is actively underway. Currently commercialized batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium batteries. Among these, lithium batteries are gaining attention for their advantages, such as the ability to freely charge and discharge with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density. In order to meet the high voltage and large capacity requirements of applications such as electric vehicles, battery systems (e.g., battery packs) comprising at least one battery group (i.e., a series connection of multiple batteries) are widely used. In such battery systems, the failure of a few batteries is highly likely to adversely affect the overall performance and safety of the battery system. Therefore, it is important to properly detect individual battery failures when operating the battery system. Multiple batteries exhibit deviations in characteristics from one another due to internal and external factors during the manufacturing process and/or use. These deviations in characteristics among multiple batteries cause voltage non-uniformity. Balancers are widely used to resolve voltage non-uniformity among multiple batteries by performing balancing processing (e.g., discharge) on each of the multiple batteries. Meanwhile, among the various types of battery failures, internal short-circuit failure is a major failure that directly or indirectly affects fire. An internal short-circuit failure refers to a condition in which a path for leakage current is created due to adverse reactions within the battery and/or the intrusion of foreign substances into the battery. Conventionally, batteries with internal short-circuit failures among multiple batteries are detected by utilizing the voltage imbalance state of multiple batteries. However, when balancing is performed, the voltage non-uniformity of multiple batteries, which is important information for detecting internal short-circuit faults, is eliminated. In other words, when detecting a battery with an internal short-circuit fault among multiple batteries, the balancing performed in the past acts as a hindering factor. The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a diagram illustrating the configuration of an electric vehicle according to the present invention in an exemplary manner. Figure 2 is a diagram referenced to illustrate an exemplary equivalent circuit of a battery. Figures 3 to 6 are reference drawings used to explain the principle of detecting internal short-circuit failures in a battery. FIGS. 7 and FIGS. 8 are flowcharts illustrating an exemplary battery management method according to a first embodiment of the present invention. FIG. 9 is a flowchart exemplarily illustrating a battery management method according to a second embodiment of the present invention. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application. Terms including ordinal numbers, such as first, second, etc., are used for the purpose of distinguishing one of the various components from the rest, and are not used to limit the components by such terms. Throughout the specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise,