Battery Cell Abnormality Diagnosis Using Frequency-Band Signal Extraction

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Solution Overview

Problem

Accurate and reliable measurement of battery cell voltage in electric vehicles is challenging due to noise signals generated during vehicle movement and varying environmental conditions, leading to unreliable diagnosis of battery cell abnormalities.

Innovation Solution

A method and apparatus that involves obtaining measurement data, extracting signals from specific frequency bands using appearance frequency counts, and generating diagnostic data through frequency and time domain conversions, with optional low-pass filtering and comparison to predefined or dynamically adjusted condition thresholds to determine battery cell abnormalities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If voltage measurement is performed in a noisy environment during vehicle movement, then the measurement can be conducted under real operating conditions, but the measurement precision deteriorates due to noise signals

Engineering Contradiction:
Improvediagnosis reliabilityVSAvoidcell voltage measurement precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent segments the voltage measurement signal into multiple frequency bands using FFT (Fast Fourier Transform). By dividing the signal spectrum into different frequency components, the system can identify and isolate noise signals from actual battery voltage variations, thereby improving measurement precision without sacrificing diagnosis reliability under real operating conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary processing system that includes FFT analysis, frequency band segmentation, and inverse FFT transformation. This intermediary layer between the raw measurement and the diagnosis algorithm filters out noise components while preserving the essential battery cell voltage information, resolving the contradiction between measurement precision and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If frequency domain analysis is applied to extract signals from measurement data, then noise reduction is improved, but the device complexity increases due to additional processing steps

Engineering Contradiction:
Improvesignal extraction accuracyVSAvoiddiagnosis system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex hardware-based filtering mechanisms with software-based signal processing algorithms (FFT and inverse FFT). This substitution allows for effective noise reduction and signal extraction through computational methods, improving measurement precision while avoiding the need for additional physical components that would increase device complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach improves noise reduction and enhances the accuracy and reliability of battery cell abnormality diagnosis by effectively distinguishing normal and abnormal conditions.

Implementation Method 1

converting the measurement data into frequency domain data; calculating the appearance frequency count for each frequency band appearing in the converted frequency domain data

Methodology Applied
Scientific EffectFast Fourier Transform:

Implementation Method 2

inversely transforming the extracted signal into time domain data to generate the diagnostic data

Methodology Applied
Scientific EffectInverse Fast Fourier Transform:

Implementation Method 3

correcting the generated diagnostic data using a low pass filter (LPF)

Methodology Applied
Scientific EffectLow pass filtering: Filter (electronic)

Data Source

PatentUS20250355048A1Apparatus and Method for Diagnosing Abnormality of Battery Cell
Publication Date: 2025.11.20 LG ENERGY SOLUTION LTD
  • US20250355048A1 patent drawing
  • US20250355048A1 patent drawing
  • US20250355048A1 patent drawing

AI summary

An apparatus and method for diagnosing an abnormality of a battery cell according to embodiments of the present invention may obtain measurement data for at least one parameter of a battery cell, extract a signal having multiple frequency bands from the measurement data to generate diagnostic data, and analyzing the generated diagnostic data to determine whether the battery cell has an abnormality.