Battery Pack SOH Calculation Error Correction

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Solution Overview

Problem

The existing methods for calculating the State of Health (SOH) of a battery pack are inaccurate due to errors in current sensor measurements and nominal capacity values, leading to difficulties in determining the precise SOH.

Innovation Solution

A method and apparatus that reduce errors in SOH calculation by integrating current values with error correction, using a flowchart and device configuration to calculate a final current integrated value and set nominal capacity, thereby eliminating errors in the SOH calculation process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If current integration method is used to calculate SOH, then SOH calculation can be performed, but measurement precision deteriorates due to current sensor errors

Engineering Contradiction:

ImproveSOH calculation capabilityVSAvoidcurrent sensor measurement accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent uses feedback by continuously monitoring the difference between integrated current values and actual capacity changes, then correcting the nominal capacity value based on this feedback to reduce cumulative errors in SOH calculation

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent changes the parameter being calculated by not directly using the raw integrated current value, but rather using a corrected value that accounts for sensor errors, transforming the calculation approach to improve precision

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If nominal capacity value from manufacturing specification is used, then calculation process is simplified, but measurement precision deteriorates due to manufacturing errors

Engineering Contradiction:

Improvecalculation process complexityVSAvoidnominal capacity value accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary action by pre-calculating and storing correction values for nominal capacity based on expected error ranges, so that during actual SOH calculation, these pre-prepared correction factors can be applied without adding complex real-time computation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary correction factor that mediates between the simple nominal capacity value and the actual capacity, allowing the system to maintain calculation simplicity while improving precision through the intermediate correction step

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11353516B2Apparatus and method for calculating SOH of battery pack

Publication Date: 2022.06.07 LG ENERGY SOLUTION LTD

AI summary

A method for calculating an accurate SOH of a battery pack by reducing an error occurring during SOH calculation of the battery pack.