US-20260126495-A1 - DEVICE AND METHOD FOR DETECTING BATTERY ABNORMAL CONDITION USING VOLTAGE DEVIATION VARIATION

Abstract

The present disclosure relates to a device and a method for detecting a battery abnormality using a voltage deviation variation. According to one embodiment of the present disclosure, the device includes: a memory configured to store at least one instruction for detecting a battery abnormality using a voltage deviation variation; and a processor configured to perform an operation according to the instruction, wherein the processor is configured to: calculate a voltage change of the battery and store the calculated voltage change as a variable; and calculate a Differential Deviation Voltage Detection (DDVD), which is a change in voltage difference among respective cells within a battery module, and detect a battery abnormality using the voltage deviation variation (DDVD) and the stored variable.

Inventors

• Kyu Min HWANG
• Hyun Jun Lee
• Ung JON
• Myeong Jae GO

Assignees

• SK ON CO., LTD.

Dates

Publication Date

20260507

Application Date

20251104

Priority Date

20241104

Claims (10)

1. 1 . A device for detecting a battery abnormality using a voltage deviation variation, the device comprising: a memory configured to store at least one instruction for detecting a battery abnormality using a voltage deviation variation; and a processor configured to perform an operation according to the instruction, wherein the processor is configured to: calculate a voltage change of the battery and store the calculated voltage change as a variable; and calculate a Differential Deviation Voltage Detection (DDVD), which is a change in voltage difference among respective cells within a battery module, and detect a battery abnormality using the Differential Deviation Voltage Detection (DDVD) and the stored variable.
2. 2 . The device according to claim 1 , wherein the processor comprises a battery equivalent-model voltage change calculation unit configured to calculate a voltage change of the battery using parameters related to a State of Charge (SOC) of the battery when a current is applied to an Equivalent Circuit Model (ECM).
3. 3 . The device according to claim 2 , wherein the processor comprises a driving-distance reflection unit configured to, when an accumulated driving distance exceeds a predetermined value, adjust a ratio of at least one of the calculated values of the voltage change in the battery equivalent model by taking into account degradation differences among cells within the battery module, and set the adjusted calculated value as a voltage deviation variation (DDVD) criterion.
4. 4 . The device according to claim 2 , wherein the parameters related to the State of Charge (SOC) include a voltage change (Δt/C 1 (I k −I k−1 ) due to capacitance of the battery equivalent model and circuit characteristics (1−Δt/R 1 C 1 ) of an RC circuit.
5. 5 . The device according to claim 3 , wherein the driving-distance reflection unit is configured to compare the calculated voltage deviation variation criterion with driving results of a normal battery, and adjust an increase or decrease of the criterion according to a current level.
6. 6 . A method for detecting a battery abnormality using a voltage deviation variation, the method comprising: calculating a voltage change of the battery and storing the calculated voltage change as a variable; and calculating a Differential Deviation Voltage Detection (DDVD), which is a change in voltage difference among respective cells within a battery module, and detecting a battery abnormality using the Differential Deviation Voltage Detection (DDVD) and the stored variable.
7. 7 . The method according to claim 6 , wherein the step of detecting a battery abnormality comprises calculating, by a battery equivalent-model voltage change calculation unit, a voltage change of the battery using parameters related to a State of Charge (SOC) of the battery when a current is applied to an Equivalent Circuit Model (ECM).
8. 8 . The method according to claim 7 , wherein the step of calculating a voltage change of the battery comprises: when an accumulated driving distance exceeds a predetermined value, by a driving-distance reflection unit, adjusting a ratio of at least one of the calculated values of the voltage change in the battery equivalent model by taking into account degradation differences among cells within the battery module; and setting the adjusted calculated value as a voltage deviation variation (DDVD) criterion.
9. 9 . The method according to claim 7 , wherein the parameters related to the State of Charge (SOC) include a voltage change (Δt/C 1 (I k −I k−1 ) due to capacitance of the battery equivalent model and circuit characteristics (1−Δt/R 1 C 1 ) of an RC circuit.
10. 10 . The method according to claim 8 , wherein the step of setting the adjusted calculated value as a voltage deviation variation (DDVD) criterion comprises: comparing the calculated voltage deviation variation criterion with driving results of a normal battery, and adjusting an increase or decrease of the criterion according to a current level.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2024-0154386, filed on Nov. 4, 2024, the disclosure of which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to a device and a method for detecting a battery abnormality using a voltage deviation variation. 2. Description of the Related Art To ensure the safety and performance of batteries used in various industries and electronic devices, battery abnormality detection technologies are essential. A battery is a device that stores and releases energy through internal chemical reactions. If excessive heat is generated during the energy storage and release processes, there are risks such as fire or explosion. Therefore, battery abnormality detection technologies may detect such risks in advance and prevent accidents. Lithium-ion batteries are efficient due to their high energy density, but when overcharging overdischarging, or short-circuiting occurs, serious safety issues may arise. Battery abnormality detection technologies can identify these issues at an early stage, thereby protecting users and the surrounding environment. In addition, battery abnormality detection technologies may analyze the state of the battery, detect early signs of failure, and enable preventive maintenance when necessary. This may prevent abnormal battery operation and extend its life cycle. Meanwhile, conventional battery abnormality detection methods primarily detect voltage changes by setting a fixed threshold value. In such conventional detection methods, if a voltage change exceeds the fixed threshold value, it is determined that the battery is abnormal. However, because it is difficult to appropriately set the threshold value for all operating conditions, it is challenging to accurately diagnose the battery state and detect abnormalities. Specifically, voltage changes may vary greatly depending on factors such as the battery state, usage environment, and temperature. Since the fixed threshold value in conventional detection methods fails to adequately reflect these diverse factors, accurate diagnosis and abnormality detection are difficult. Further, when a battery experiences large current changes, even a normal cell may exceed a fixed threshold value. For example, during fast charging or high-power discharging, even a healthy battery may exhibit a large voltage change. However, relying solely on a fixed threshold value in such cases increases the likelihood of misdiagnosing a normal battery as defective. Furthermore, conventional battery abnormality detection methods cannot distinguish between voltage changes naturally caused by battery aging and those caused by actual abnormalities, which makes accurate diagnosis of the battery state difficult. An aged battery may exhibit a different voltage change pattern, but it is difficult to distinguish voltage and current changes caused by aging using only the fixed threshold value. SUMMARY OF THE INVENTION According to one aspect of the present disclosure, there are provided a device and a method for detecting signs of battery abnormality before a fire occurs, by setting a variable threshold value based on a current change using a relational equation of a battery equivalent model, and detecting the battery abnormality based on the set variable threshold value. According to another aspect of the present disclosure, in cases where parameters used in the relational equation of the battery equivalent model vary depending on battery degradation or ambient temperature, errors may occur in the calculated threshold value. In this regard, in some embodiments, by monitoring changes in cell deviation within a battery module instead of relying on the relational equation of a single cell, the effect of parameter errors may be reduced using relative values. A device for detecting a battery abnormality using a voltage deviation variation according to one embodiment of the present disclosure may include: a memory configured to store at least one instruction for detecting a battery abnormality using a voltage deviation variation; and a processor configured to perform an operation according to the instruction, wherein the processor may be configured to: calculate a voltage change of the battery and store the calculated voltage change as a variable; and calculate a Differential Deviation Voltage Detection (DDVD), which is a change in voltage difference among respective cells within a battery module, and detect a battery abnormality using the Differential Deviation Voltage Detection (DDVD) and the stored variable. According to one embodiment, the processor may include a battery equivalent-model voltage change calculation unit configured to calculate a voltage change of the battery using parameters related to a State of Charge (SOC) of the battery when a current is applied to an Equivalent