Arc Fault Detection via Optical Absorption Spectroscopy

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional arc fault detection methods in electrical switchgear are inadequate as they rely solely on light effects, which can be misleading due to extraneous light, and are too slow to initiate countermeasures, often resulting in delayed detection and significant damage.

Innovation Solution

A device with a sensor that detects absorption lines of incident light, specifically Fraunhofer lines of metals like copper, aluminum, or iron, to generate an evaluation signal for rapid and reliable arc fault detection, allowing for immediate countermeasures without additional measured variables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional light-only detection is used, then device complexity is reduced, but reliability of arc fault detection deteriorates due to false positives from extraneous light

Engineering Contradiction:
Improvedetection system complexityVSAvoidarc fault detection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies spectral analysis by detecting specific wavelength ranges (380-780 nm visible light, 780-1400 nm near-infrared) characteristic of arc fault radiation. The sensor system identifies the unique spectral fingerprint of arc faults rather than relying on overall light intensity, enabling discrimination between arc faults and extraneous light sources while maintaining system reliability.

Inventive Principle:
Principle #32Color changes

2Reliability

If additional measured variables (current, pressure) are monitored, then arc fault detection reliability improves, but detection speed deteriorates due to slower measurement response time exceeding 10 ms

Engineering Contradiction:
Improvearc fault detection reliabilityVSAvoiddetection speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent extracts and utilizes only the optically active material vaporized during arc faults as the detection parameter. By focusing exclusively on analyzing the spectral characteristics of light absorbed by vaporized materials rather than monitoring multiple physical variables simultaneously, the system achieves rapid detection within milliseconds while maintaining high reliability through specific spectral fingerprint identification.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If multiple measured variables are evaluated, then measurement precision improves for distinguishing arc faults, but loss of time increases due to extended evaluation duration

Engineering Contradiction:
Improvearc fault identification precisionVSAvoidevaluation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system achieves precise arc fault identification by analyzing the spectral composition and absorption characteristics of light in specific wavelength ranges. By detecting the unique spectral fingerprint created when arc faults vaporize specific materials (showing characteristic absorption lines), the system obtains high measurement precision through optical analysis alone, eliminating the need for time-consuming evaluation of multiple physical variables.

Inventive Principle:
Principle #32Color changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables swift and reliable arc fault detection within milliseconds, allowing for timely countermeasures to minimize damage by differentiating arc faults from other light effects without relying on slower overcurrent or pressure monitoring methods.

Implementation Method 1

a sensor for detecting absorption lines of the incident light

Methodology Applied
Scientific EffectAbsorption Spectroscopy: Absorption Spectroscopy

Implementation Method 2

the sensor detects absorption lines of copper, aluminum, or iron (Cu, Al, Fe), in particular Fraunhofer lines

Methodology Applied
Scientific EffectFraunhofer lines: Absorption (EM radiation)

Data Source

PatentEP3300538B1Device for recognizing an arcing fault, and electrical switchgear
Publication Date: 2023.06.28 SIEMENS AG
  • EP3300538B1 patent drawingFigure 1
  • EP3300538B1 patent drawingFigure 2~3
  • EP3300538B1 patent drawing

AI summary

Disclosed is a device for recognizing an arcing fault in incident light, comprising a sensor for detecting absorption lines of the incident light, and an evaluation unit which generates an evaluation signal when characteristic absorption lines are detected.