Energy Storage Degradation Evaluation During Continuous Charge-Discharge

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Solution Overview

Problem

Current energy storage systems used for improving electric power quality cannot be stopped for degradation evaluation, as they must operate continuously, and existing methods for estimating degradation over long periods or through remote monitoring are not feasible for these systems.

Innovation Solution

An evaluation device that includes a feature value calculator and a degradation evaluator, which calculates feature values based on voltage measurements and evaluates degradation by comparing charge-discharge command value distributions to a reference distribution, allowing for continuous operation and accurate long-term degradation assessment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the energy storage system is stopped to perform charge-discharge test for degradation evaluation, then the degradation evaluation precision is improved, but the system operation continuity deteriorates

Engineering Contradiction:
Improvedegradation evaluation precisionVSAvoidsystem operation continuity
Core Design Contradiction:
Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The patent creates a virtual copy of the charge-discharge test environment by generating simulated charge-discharge command values that replicate actual operating conditions. Instead of stopping the system for physical testing, the invention processes historical operation data through simulation to evaluate degradation, thereby maintaining system operation continuity while achieving degradation assessment

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent performs preliminary degradation evaluation by analyzing historical charge-discharge command values and voltage data before the system would need to be stopped for testing. By preprocessing and evaluating past operation data, the system can assess degradation trends without interrupting current operation, and prepare maintenance plans in advance

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the energy storage system operates continuously for 24 hours and 365 days to improve electric power quality, then the system reliability is improved, but the ability to perform degradation evaluation deteriorates

Engineering Contradiction:
Improvesystem reliabilityVSAvoiddegradation evaluation capability
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary data processing system that acts as a mediator between continuous system operation and degradation evaluation. The system uses charge-discharge command values and voltage data as intermediary parameters to indirectly assess degradation without requiring system shutdown, enabling both continuous operation and evaluation capability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/physical charge-discharge testing method with a computational analysis approach. Instead of applying mechanical stress through actual charge-discharge cycles to evaluate degradation, the system substitutes this with algorithmic processing of historical command values and voltage data to assess degradation trends

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

3Measurement precision

If charge-discharge test is performed by stopping the energy storage system, then the degradation evaluation precision is improved, but the productivity deteriorates

Engineering Contradiction:
Improvedegradation evaluation precisionVSAvoidsystem productivity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent ensures continuous useful action by maintaining system operation while performing degradation evaluation through data analysis. The charge-discharge command value processing and voltage data analysis occur continuously in the background without interrupting the energy storage system's productive function of improving electric power quality

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP3719515B1Evaluation device, evaluation method, and computer program
Publication Date: 2023.11.08 KK TOSHIBA
  • EP3719515B1 patent drawingFigure 1
  • EP3719515B1 patent drawingFigure 2~3
  • EP3719515B1 patent drawingFigure 4

AI summary

[Problem to be solved] An embodiment of the present invention evaluates degradation of an energy storage system without stopping a function of the energy storage system. [Means for solving the Problem] According to one embodiment, an evaluation device includes a feature value calculator and a degradation evaluator. The feature value calculator calculates a feature value of an energy storage device based on voltage values measured from the energy storage device being subjected to charge-discharge-control according to charge-discharge command values. The degradation evaluator derives an evaluation function of a degradation state of the energy storage device according to a difference between a distribution of the charge-discharge command values and a reference distribution. The degradation evaluator evaluates the degradation state of the energy storage device, based on the evaluation function and the calculated feature value.