EP-4741851-A1 - BATTERY DIAGNOSIS DEVICE AND OPERATION METHOD THEREOF

EP4741851A1EP 4741851 A1EP4741851 A1EP 4741851A1EP-4741851-A1

Abstract

A battery diagnosis apparatus according to an embodiment disclosed herein includes a pulse application unit configured to apply a plurality of pulses to a battery and a controller configured to obtain a first voltage corresponding to at least any one pulse among the plurality of pulses, calculate a voltage change rate based on the first voltage and a time during which the first voltage is obtained, and diagnose abnormality of the battery based on the voltage change rate.

Inventors

PARK, JAE DONG
YOON, HO BYUNG
LEE, JEONG HWAN

Assignees

LG Energy Solution, Ltd.

Dates

Publication Date: 20260513
Application Date: 20240722

Claims (20)

A battery diagnosis apparatus comprising: a pulse application unit configured to apply a plurality of pulses to a battery; and a controller configured to: obtain a first voltage corresponding to at least any one pulse among the plurality of pulses; calculate a voltage change rate based on the first voltage and a time during which the first voltage is obtained; and diagnose abnormality of the battery based on the voltage change rate.
The battery diagnosis apparatus of claim 1, wherein the pulse application unit is further configured to apply at least any one of a charging pulse and a discharging pulse to the battery.
The battery diagnosis apparatus of claim 2, wherein the pulse application unit is further configured to alternately apply the charging pulse, a rest period, and the discharging pulse to the battery.
The battery diagnosis apparatus of claim 1, wherein the controller is further configured to obtain, as the first voltage, a voltage corresponding to a discharging pulse among the plurality of pulses.
The battery diagnosis apparatus of claim 1, wherein the controller is further configured to: calculate, as an average voltage, an average of the first voltage corresponding to the at least any one pulse; and diagnose abnormality of the battery based on a change rate of the average voltage.
The battery diagnosis apparatus of claim 1, wherein the controller is further configured to: calculate, as an average voltage, an average of the first voltage corresponding to each of the plurality of pulses; and diagnose abnormality of the battery based on a change rate of the average voltage.
The battery diagnosis apparatus of claim 1, wherein the controller is further configured to: convert a time axis of the first voltage into a logscale; and calculate, as the voltage change rate, a change rate of the first voltage with respect to the time axis converted into the logscale.
The battery diagnosis apparatus of claim 7, wherein the controller is further configured to calculate the voltage change rate by calculating a differential value (dV/d(log(t)) of the first voltage with respect to a logscale time.
The battery diagnosis apparatus of claim 8, wherein the controller is further configured to diagnose abnormality of a battery based on at least one of a change rate of the differential value of the first voltage with respect to the logscale time, a peak value of the differential value of the first voltage with respect to the logscale time, a maximum value of the differential value of the first voltage with respect to the logscale time, a minimum value of the differential value of the first voltage with respect to the logscale time, and a normal distribution of the differential value of the first voltage with respect to the logscale time.
The battery diagnosis apparatus of claim 1, wherein the controller is further configured to obtain the first voltage based on a voltage after a set time from application of the discharging pulse among the plurality of pulses.
The battery diagnosis apparatus of claim 1, wherein the controller is further configured to: fit the first voltage into an equation; and calculate the voltage change rate based on the equation.
The battery management apparatus of claim 1, wherein the controller is further configured to diagnose abnormality of each of the plurality of battery cells included in the battery when each of the plurality of battery cells has a same degree of degradation.
The battery diagnosis apparatus of claim 1, wherein the controller is further configured to extract the first voltage by correcting temperature imbalance of the battery.
An operating method of a battery diagnosis apparatus, the operating method comprising: applying a plurality of pulses to a battery; obtaining a first voltage corresponding to at least any one pulse among the plurality of pulses; calculating a voltage change rate based on the first voltage and a time during which the first voltage is obtained; and diagnosing abnormality of the battery based on the voltage change rate.
The operating method of claim 14, wherein the applying of the plurality of pulses to the battery comprises alternately applying a charging pulse and a discharging pulse to the battery.
The operating method of claim 14, wherein the obtaining of the first voltage corresponding to the at least any one pulse among the plurality of pulses comprises calculating, as an average voltage, an average of the first voltage corresponding to the at least any one pulse.
The operating method of claim 14, wherein the obtaining of the first voltage corresponding to the at least any one pulse among the plurality of pulses comprises calculating, as an average voltage, an average of the first voltage corresponding to each of the plurality of pulses.
The operating method of claim 14, wherein the calculating of the voltage change rate based on the first voltage and the time during which the first voltage is obtained comprises: converting a time axis of the first voltage into a logscale; and calculating, as the voltage change rate, a change rate of the first voltage with respect to the time axis converted into the logscale.
The operating method of claim 18, wherein the calculating, as the voltage change rate, of the change rate of the first voltage with respect to the time axis converted into the logscale comprises calculating a differential value (dV/d(log(t)) of the first voltage with respect to a logscale time.
The operating method of claim 19, wherein the diagnosing of abnormality of the battery based on the voltage change rate comprises diagnosing abnormality of a battery based on at least one of a change rate of the differential value of the first voltage with respect to the logscale time, a peak value of the differential value of the first voltage with respect to the logscale time, a maximum value of the differential value of the first voltage with respect to the logscale time, a minimum value of the differential value of the first voltage with respect to the logscale time, and a normal distribution of the differential value of the first voltage with respect to the logscale time.

Description

[TECHNICAL FIELD] CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0105935 filed in the Korean Intellectual Property Office on August 11, 2023, the entire content of which is incorporated herein by reference. TECHNICAL FIELD Embodiments disclosed herein relate to a battery diagnosis apparatus and an operating method thereof. [BACKGROUND ART] Recently, research and development of secondary batteries have been actively performed. Herein, the secondary batteries, which are chargeable/dischargeable batteries, may include all of conventional nickel (Ni)/cadmium (Cd) batteries, Ni/metal hydride (MH) batteries, etc., and recent lithium-ion batteries. Among the secondary batteries, a lithium-ion battery has a much higher energy density than those of the conventional Ni/Cd batteries, Ni/MH batteries, etc. Moreover, the lithium-ion battery may be manufactured to be small and lightweight, such that the lithium-ion battery has been used as a power source of mobile devices, and recently, a use range thereof has been extended to power sources for electric vehicles, attracting attention as next-generation energy storage media. The battery measures and determines the state thereof through a battery management system (BMS) mounted thereon so as to be used normally. Thus, there are various diagnosis methods for cases where various information measured through BMS falls beyond a normal range or shows abnormality. However, a behavior of the battery may be changed variously for a state of charge (SOC) and a state of health (SOH), making it difficult to accurately derive abnormal diagnosis. [DISCLOSURE] [TECHNICAL PROBLEM] Embodiments disclosed herein aim to provide a battery diagnosis apparatus and an operating method thereof in which a battery may be precisely diagnosed. Embodiments disclosed herein aim to provide a battery diagnosis apparatus and an operating method thereof in which a battery may be diagnosed based on a response to a pulse applied to the battery. Technical problems of the embodiments disclosed herein are not limited to the above-described technical problems, and other unmentioned technical problems would be clearly understood by one of ordinary skill in the art from the following description. [TECHNICAL SOLUTION] A battery diagnosis apparatus according to an embodiment disclosed herein includes a pulse application unit configured to apply a plurality of pulses to a battery and a controller configured to obtain a first voltage corresponding to at least any one pulse among the plurality of pulses, calculate a voltage change rate based on the first voltage and a time during which the first voltage is obtained, and diagnose abnormality of the battery based on the voltage change rate. In an embodiment, the pulse application unit may be further configured to apply at least any one of a charging pulse and a discharging pulse to the battery. In an embodiment, the pulse application unit may be further configured to alternately apply the charging pulse, a rest period, and the discharging pulse to the battery. In an embodiment, the pulse application unit may be further configured to obtain, as the first voltage, a voltage corresponding to a discharging pulse among the plurality of pluses. In an embodiment, the controller may be further configured to calculate, as an average voltage, an average of the first voltage corresponding to the at least any one pulse and diagnose abnormality of the battery based on a change rate of the average voltage. In an embodiment, the controller may be further configured to calculate, as an average voltage, an average of the first voltage corresponding to each of the plurality of pulses and diagnose abnormality of the battery based on a change rate of the average voltage. In an embodiment, the controller may be further configured to convert a time axis of the first voltage into a logscale and calculate, as the voltage change rate, a change rate of the first voltage with respect to the time axis converted into the logscale. In an embodiment, the controller may be further configured to calculate the voltage change rate by calculating a differential value (dV/d(log(t)) of the first voltage with respect to a logscale time. In an embodiment, the controller may be further configured to diagnose abnormality of a battery based on at least one of a change rate of the differential value of the first voltage with respect to the logscale time, a peak value of the differential value of the first voltage with respect to the logscale time, a maximum value of the differential value of the first voltage with respect to the logscale time, a minimum value of the differential value of the first voltage with respect to the logscale time, and a normal distribution of the differential value of the first voltage with respect to the logscale time. In an embodiment, the controller may be further configured to obtain the first voltage