Non-invasive RF Monitoring of Gas Insulated Absorber Load

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Solution Overview

Problem

Conventional gas-insulated electrical apparatus maintenance requires shutdowns for gas diagnostics, leading to challenges like gas loss, contamination, and high costs, while failing to provide real-time information on absorber load and impurity introduction rates.

Innovation Solution

A non-invasive monitoring system using RF electromagnetic radiation to assess the load of absorbers within the gas chamber without physical access, allowing for continuous operation and reducing equipment costs by over 100 times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional gas diagnostics is performed to measure insulation gas composition, then the water concentration and impurity levels can be determined, but the gas-insulated electrical apparatus must be shut down, leading to gas loss, contamination risk, and high costs

Engineering Contradiction:
Improvewater concentration measurementVSAvoidgas loss and contamination risk
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical extraction and analysis system with an electromagnetic field-based monitoring system. Instead of physically extracting gas samples through connectors and tubes (mechanical system), the invention uses RF cavity resonators and electromagnetic radiation to non-invasively detect water concentration and absorber load through the chamber walls, eliminating the need for physical access and sample extraction

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

Solution Approach 2:

The patent introduces electromagnetic radiation as an intermediary to transfer information about the insulation gas composition and absorber load from the interior of the gas chamber to the exterior monitoring devices. The RF signals penetrate the chamber walls and interact with the gas and absorber, carrying diagnostic information without requiring physical extraction or direct contact with the gas

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If gas diagnostics is performed with an analyzer, then the insulation gas quality can be assessed, but the measurement time is long (15-20 minutes) and the equipment costs are very high

Engineering Contradiction:
Improveinsulation gas quality assessmentVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the complex mechanical analyzer system with a simplified electromagnetic measurement system using RF cavity resonators. The measurement process is accelerated by using resonant frequency detection, which provides rapid feedback on gas composition and absorber load without requiring the lengthy extraction, transport, and analysis steps of conventional analyzers

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

Solution Approach 2:

The patent enables continuous monitoring of the insulation gas quality and absorber load through ongoing RF measurements. Instead of periodic discrete measurements requiring shutdowns, the system can continuously or frequently monitor the gas chamber conditions while the apparatus remains operational, eliminating measurement interruptions and providing real-time diagnostic information

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If conventional gas diagnostics is performed, then the water concentration can be measured, but the apparatus must be shut down, creating challenges for maintenance scheduling and preventing short service intervals

Engineering Contradiction:
Improvewater concentration measurementVSAvoidmaintenance scheduling flexibility
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent enables continuous monitoring of the insulation gas quality and absorber load through ongoing RF measurements. Instead of periodic discrete measurements requiring shutdowns, the system can continuously or frequently monitor the gas chamber conditions while the apparatus remains operational, eliminating measurement interruptions and providing real-time diagnostic information for optimized maintenance scheduling

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent implements a self-monitoring system where the gas-insulated electrical apparatus continuously assesses its own internal condition through RF cavity resonators and electromagnetic field interactions. The system automatically detects changes in water concentration, absorber load, and gas composition without requiring external intervention or shutdowns, enabling the apparatus to self-diagnose and alert operators when maintenance is needed

Inventive Principle:
Principle #25Self-service

4Reliability

If an absorber is added to absorb impurities, then the adverse effects of water and decomposition products can be mitigated, but the absorber load must be monitored to determine when service is needed

Engineering Contradiction:
Improveprotection against impuritiesVSAvoidabsorber load monitoring
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical or chemical sensing methods for monitoring absorber load with electromagnetic field-based detection. RF cavity resonators and electromagnetic radiation interact with the absorber material and the impurities it has absorbed, providing information about the absorber's saturation level through changes in resonant frequency, Q-factor, or other electromagnetic characteristics, without requiring physical access or complex chemical analysis

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

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 real-time monitoring of absorber load and impurity introduction rates, improving safety and maintenance timing without gas loss or contamination, and significantly lowering equipment costs.

Implementation Method 1

A non-invasive monitoring system using RF electromagnetic radiation to assess the load of absorbers within the gas chamber

Methodology Applied
Scientific EffectRF electromagnetic radiation: Electromagnetic Induction

Implementation Method 2

an absorber for absorbing impurities present in the insulation gas

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

an adsorbent and an electrochemical device for determining a degree of deterioration of the adsorbent

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3570394B1Gas insulated electrical apparatus and method for monitoring the load of an absorber in a gas-insulated electrical apparatus
Publication Date: 2022.03.16 HITACHI ENERGY SWITZERLAND AG
  • EP3570394B1 patent drawingFigure 1a~1d
  • EP3570394B1 patent drawingFigure 2

AI summary

A gas-insulated electrical apparatus (1), in particular a switchgear, includes: a gas chamber (2) filled with an insulation gas and an absorber (10) for absorbing impurities present in the insulation gas. The absorber (10) is positioned in the gas chamber (2). The gas-insulated electrical apparatus (1) further includes a monitoring device (20) for non-invasive monitoring of a load of the absorber (10). A method for monitoring a load of an absorber (10) for absorbing impurities present in an insulation gas of a gas-insulated electrical apparatus (1), wherein the absorber (10) is positioned in a gas chamber (2) of the gas-insulated electrical apparatus (1), the method includes: non-invasively measuring a physical property of the absorber (10) or of a compartment (3) of the gas chamber, in which the absorber (10) is positioned. The physical property allows conclusions on the load of the absorber (10).