Battery Capacity Monitoring for Parallel Cell Fault Detection

Solution Overview

Problem

The challenge lies in detecting abnormalities in the parallel connection structure of unit cells within batteries, particularly the risk of increased fire and explosion due to permanent failures in the charging/discharging process, which existing technologies fail to address effectively.

Innovation Solution

A battery diagnosis device and method that monitors the time-dependent change in full charge capacity by collecting and analyzing charge/discharge data, determining estimated capacity values, and diagnosing abnormalities by comparing these values against threshold capacities, thereby identifying faulty unit cells and preventing potential hazards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the parallel connection structure of unit cells is used in battery, then the energy density and recharging capability are improved, but the risk of fire and explosion increases due to permanent failures in some unit cells

Engineering Contradiction:

Improveenergy densityVSAvoidfire and explosion risk

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by continuously monitoring the full charge capacity of the battery over time and comparing it with a reference value before permanent failures occur. The diagnosis device detects abnormalities in the parallel connection structure by identifying when the full charge capacity falls below the reference value, enabling preventive maintenance before fire or explosion hazards develop.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If permanent failure occurs in some unit cells of the parallel connection structure, then charging/discharging concentrates in normal unit cells, but this leads to increased fire and explosion risks

Engineering Contradiction:

Improvecharging/discharging capacityVSAvoidfire and explosion risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements feedback by continuously measuring the full charge capacity of the battery and comparing it with a reference value stored in memory. When the measured capacity falls below the reference value, the system generates an abnormality signal indicating potential permanent failures in the parallel connection structure, allowing operators to take corrective action before hazardous conditions develop.

Inventive Principle:

Principle #23Feedback

3Reliability

If existing technologies are used for battery monitoring, then basic battery status can be tracked, but abnormalities in parallel connection structure cannot be detected early enough to prevent fires and explosions

Engineering Contradiction:

Improvebattery operation safetyVSAvoiddetection time for abnormalities

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by continuously monitoring the full charge capacity of the battery over time and comparing it with a reference value before permanent failures occur. The diagnosis device detects abnormalities in the parallel connection structure by identifying when the full charge capacity falls below the reference value, enabling preventive maintenance before fire or explosion hazards develop.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by continuously measuring the full charge capacity of the battery and comparing it with a reference value stored in memory. When the measured capacity falls below the reference value, the system generates an abnormality signal indicating potential permanent failures in the parallel connection structure, allowing operators to take corrective action before hazardous conditions develop.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20240066993A1Battery Diagnosis Device, Battery Management System, Battery Pack, Electric Vehicle And Battery Diagnosis Method

Publication Date: 2024.02.29 LG ENERGY SOLUTION LTD

AI summary

A battery diagnosis device for a battery including a parallel connection structure of unit cells includes a processor and memory having programmed thereon instructions that, when executed, are configured to cause the processor to collect charge/discharge data including a voltage time series indicating a time-dependent change of a voltage across the battery and a current time series indicating a time-dependent change of a charge/discharge current flowing through the battery; determine an estimated capacity value indicating a full charge capacity of the battery based on the charge/discharge data; and diagnose an abnormality in the parallel connection structure by monitoring a time-dependent change of the estimated capacity value.