Battery SOC Estimation Using Differential OCV Peak Filtering

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Solution Overview

Problem

Existing technologies face challenges in accurately analyzing the state of charge (SOC) and voltage profile of a battery module, as they are not capable of accurately analyzing the state of charge (SOC) and voltage profile of a battery module, as they include noise and errors, which affect the management of battery state.

Innovation Solution

A battery management apparatus and method that includes a sensor to obtain voltage and a controller to generate differential profiles for first and second differential values, detect peak values, and determine the state of the battery unit based on these profiles, reducing noise influence through data processing algorithms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a charging/discharging test is conducted to estimate OCV profile for SOC management, then the state of charge can be monitored, but the measured OCV profile includes noise and errors that reduce analysis accuracy

Engineering Contradiction:
ImproveSOC measurement accuracyVSAvoidOCV profile data reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent extracts and removes noise components from the OCV profile data through filtering operations. The controller separates the useful OCV signal from noise and errors, keeping only the meaningful data for SOC estimation while discarding the harmful noise components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary processing layer (filtering algorithm) between the raw OCV measurement and the final SOC estimation. This intermediary process cleans the data by removing noise while preserving the essential OCV characteristics needed for accurate SOC management.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If raw OCV data is used directly for battery state analysis, then the process is simple, but the noise and errors prevent clear analysis of battery state

Engineering Contradiction:
Improvedata processing simplicityVSAvoidbattery state analysis accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies a filtering operation that processes only the essential noise removal needed for accurate analysis, without over-complicating the data processing. The filter removes sufficient noise to enable clear battery state analysis while maintaining reasonable processing simplicity.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4711782A1Battery management apparatus and operation method therefor
Publication Date: 2026.03.18 LG ENERGY SOLUTION LTD
  • EP4711782A1 patent drawingFigure 1
  • EP4711782A1 patent drawingFigure 2
  • EP4711782A1 patent drawingFigure 3A

AI summary

A battery management apparatus according to an embodiment disclosed herein includes a sensor configured to obtain a voltage of a battery unit and a controller configured to generate a differential profile for a first differential value that is variance of the voltage with respect to a variance of a state of charge (SOC) of the battery unit, based on the SOC and the voltage of the battery unit, detect an SOC corresponding to each of second differential values included in a threshold range among second differential values obtained by differentiating the differential profile, detect, from the differential profile, peak values of the differential profile among first differential values corresponding to the detected SOC, and determine a state of the battery unit based on the peak values of the differential profile.