Battery Module SOC Change-Rate Defect Detection

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Solution Overview

Problem

Existing battery management systems struggle to detect defects in battery modules with multiple cells connected in parallel, particularly identifying the number of abnormal cells, which can lead to in-rush currents and damage due to capacity differences.

Innovation Solution

A battery management apparatus and method that includes a voltage measuring unit, current measuring unit, and a control unit to estimate State Of Charge (SOC) and calculate an accumulated change rate, comparing it with a reference rate to detect defects and the number of abnormal cells within the battery module.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a plurality of batteries are connected in parallel to increase capacity, then the battery module can provide higher capacity, but it becomes difficult to monitor each battery individually and detect defects

Engineering Contradiction:
Improvebattery capacityVSAvoiddefect detection accuracy
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent segments the monitoring task by dividing the battery module into individual battery units, each with its own monitoring circuit. The control unit separately measures voltage and current for each battery cell connected in parallel, enabling individual defect detection while maintaining the high capacity benefit of parallel connection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary control unit that acts as a mediator between the parallel-connected batteries and the monitoring system. This control unit collects data from each battery through separate measurement circuits and performs centralized analysis to detect defects, resolving the conflict between parallel connection and individual monitoring.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If individual battery monitoring is implemented in parallel battery modules, then defect detection capability is improved, but system complexity and cost increase

Engineering Contradiction:
Improvedefect detection accuracyVSAvoidmonitoring system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the monitoring functions by using a single control unit to handle data from all parallel-connected batteries. Instead of having separate monitoring systems for each battery, the control unit consolidates voltage and current measurements from all cells, reducing overall system complexity while maintaining individual defect detection capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control unit is designed with multi-functionality, serving as both the central processing unit and the data collection point for all parallel-connected batteries. It performs multiple functions including voltage measurement, current measurement, SOC estimation, and defect detection for the entire battery module, reducing the need for separate dedicated components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Quantity of substance

If multiple battery modules are used to increase capacity, then the battery system can provide higher capacity, but in-rush current from capacity differences can cause damage

Engineering Contradiction:
Improvebattery capacityVSAvoidin-rush current damage
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent implements feedback mechanisms where the control unit continuously monitors the SOC (State of Charge) of each battery module and uses this information to control the charging process. By providing feedback on the actual SOC values, the system can adjust charging current distribution to prevent in-rush current damage while maintaining high capacity operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary SOC estimation for each battery module before charging begins. This preliminary action allows the control unit to pre-calculate appropriate charging current distribution, preventing in-rush current damage by ensuring balanced charging from the start, rather than reacting to imbalances after they occur.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3998490B1Battery management apparatus and method
Publication Date: 2025.10.08 LG ENERGY SOLUTION LTD
  • EP3998490B1 patent drawingFigure 1~2
  • EP3998490B1 patent drawingFigure 3
  • EP3998490B1 patent drawingFigure 4~5

AI summary

A battery management apparatus according to an embodiment of the present disclosure includes a voltage measuring unit configured to measure a voltage of a battery module and output a measured voltage value; a current measuring unit configured to measure a charging current of the battery module and output a measured current value; and a control unit configured to receive the measured voltage value and the measured current value, estimate a SOC (State Of Charge) of the battery module based on the measured voltage value and the measured current value, calculate an accumulated change rate by adding up a change rate of the estimated SOC per unit time, and detect whether the battery module has a defect by comparing the calculated accumulated change rate with a reference change rate.