Gas-Insulated Switchgear Fault Localization Using Time-Reversed Waves

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Solution Overview

Problem

Current fault localization methods in gas-insulated switchgear are inaccurate due to complex wave propagation and interference within the switchgear, leading to significant localization errors and increased maintenance costs.

Innovation Solution

A fault localization system using transceivers and controllers that generate time-reversed probe signals to focus electromagnetic waves at the fault location, allowing for precise distance calculation based on the time difference between emission and reception, enhancing accuracy and reducing the need for multiple antennas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If time of flight method is used with multiple antennas, then fault location can be determined, but localization accuracy deteriorates due to wave reflections and interferences in the complex wave guide structure

Engineering Contradiction:
Improvefault localization accuracyVSAvoidwave propagation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies time reversal of the detected signal to generate the probe signal. Instead of directly using the received electromagnetic wave information for localization, the system inverts the time sequence of the detected signal and uses it to generate a probe signal that, when radiated, focuses energy back at the fault location, thereby achieving accurate localization despite complex wave propagation effects

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The system uses the naturally detected electromagnetic wave from the fault to generate its own probe signal through time reversal. The fault-generated wave itself serves as the basis for creating the probing signal, eliminating the need for external complex signal generation systems and simplifying the device while maintaining accuracy

Inventive Principle:
Principle #25Self-service

2Reliability

If multiple antennas are deployed for fault detection, then coverage is improved, but system complexity and cost increase

Engineering Contradiction:
Improvefault detection reliabilityVSAvoidnumber of antennas
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The transceiver is designed to perform multiple functions: it can detect electromagnetic waves from faults, generate probe signals through time reversal, radiate the probe waves, and receive response waves. This multi-functionality allows a single transceiver to replace what would traditionally require multiple specialized antennas, reducing system complexity while maintaining detection reliability

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

Solution Approach 2:

The patent combines the detection function and the probing function into a single transceiver unit. By merging these functions and using time reversal to generate probe signals from detected signals, the system eliminates the need for separate antenna arrays, thereby reducing device complexity and cost while preserving fault detection reliability

Inventive Principle:
Principle #5Merging (Combining)

3Loss of information

If traditional electromagnetic wave detection is used, then fault presence can be detected, but localization accuracy deteriorates due to path changes from reflections and refractions

Engineering Contradiction:
Improvefault location information accuracyVSAvoidwave interference and path distortion
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of complex wave propagation (reflections, refractions, path changes) into a beneficial effect through time reversal. The same complex waveguide structure that distorts direct waves also focuses the time-reversed probe waves back at the fault location, transforming the distortion mechanism into a focusing mechanism that enhances localization accuracy

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

The system achieves enhanced accuracy in fault localization, reducing intervention and downtime costs by focusing probe waves at the fault location, and can operate with a single transceiver, improving reliability and simplicity.

Implementation Method 1

the controller being configured, for each transceiver, to compute a time reversed signal by performing time reversal based on the corresponding detection signal

Methodology Applied
Scientific EffectTime reversal:

Implementation Method 2

the probe electromagnetic wave radiated by the corresponding transceiver focuses at the same location as the fault

Methodology Applied
Scientific EffectElectromagnetic wave focusing: Focusing

Implementation Method 3

When a partial discharge occurs, such a discharges generates electromagnetic waves, generally in the ultra-high frequency band

Methodology Applied
Scientific EffectElectromagnetic wave propagation:

Implementation Method 4

the electromagnetic waves originating from a partial discharge undergo reflections, refractions with medium changes (gas/insulator/gas) and diffractions

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 5

the electromagnetic waves originating from a partial discharge undergo reflections, refractions with medium changes (gas/insulator/gas) and diffractions

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 6

the electromagnetic waves originating from a partial discharge undergo reflections, refractions with medium changes (gas/insulator/gas) and diffractions

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 7

Based on the time of arrival of these electromagnetic waves at each antenna, a location of the partial discharge is estimated

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Data Source

PatentEP3879284B1Fault localization system and associated fault localization method
Publication Date: 2024.06.05 GENERAL ELECTRIC TECH GMBH
  • EP3879284B1 patent drawingFigure 1
  • EP3879284B1 patent drawingFigure 2
  • EP3879284B1 patent drawingFigure 3

AI summary

The invention concerns a fault localization system (2) comprising: - at least one transceiver (12) meant to be arranged within a gas-insulated switchgear (4) and configured to output a detection signal corresponding to a received electromagnetic wave, to radiate, at an emission time, a probe electromagnetic wave based on a probe signal, and to output a response signal associated to a response electromagnetic wave corresponding to a response of the environment of the transceiver (12) to the probe electromagnetic wave, and received at a reception time; and - a controller (14) configured to compute a time reversed signal based on the detection signal, to generate the probe signal based on the time reversed signal, to input the probe signal to the transceiver (12), and to determine information relating to the location of a fault (3) based on a time difference between the emission time and the reception time.