Vacuum Interrupter Failure Detection via Oil Hydrogen Analysis

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Solution Overview

Problem

Current methods lack a simple and reliable way to detect vacuum interrupter failures in on-load tap-changers, which can lead to catastrophic failures such as short circuits or fires if not promptly addressed.

Innovation Solution

A method and device that repeatedly measure hydrogen content in the oil of the tap changer, using a hydrogen sensor to compare measured hydrogen levels with predicted levels based on switching history, determining failure when deviations exceed a threshold, and triggering warnings or limiting operations to prevent damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If vacuum interrupters are used in on-load tap-changers to prevent arcing in oil, then electrical contact wear and arcs in oil are reduced, but there is no simple and reliable method to detect vacuum interrupter failures

Engineering Contradiction:
Improvearcing in oilVSAvoidvacuum interrupter failure detection
Core Design Contradiction:
Object-affected harmful factorsVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces hydrogen content in insulating oil as an intermediary indicator to detect vacuum interrupter failures. Instead of directly monitoring the vacuum interrupter's operational status, the system measures hydrogen content (using gas chromatography or other detection methods) which increases when vacuum interrupters fail and cause arcing in the oil. This intermediary measurement provides an indirect but reliable detection method for vacuum interrupter health status.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If no failure detection system is implemented, then device complexity is reduced, but catastrophic failures such as short circuits or fires may occur

Engineering Contradiction:
Improvedetection system complexityVSAvoidsystem safety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent replaces complex mechanical or electrical monitoring systems with a chemical analysis approach. Instead of using sophisticated sensors to directly detect vacuum interrupter status, the system uses chemical composition analysis (hydrogen content measurement) of the insulating oil to infer system health. This substitution simplifies the detection system while maintaining high reliability for failure detection.

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

3Measurement precision

If hydrogen content measurement is implemented to detect vacuum interrupter failures, then failure detection capability is improved, but measurement and analysis complexity increases

Engineering Contradiction:
Improvefailure detection accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent focuses on measuring a specific parameter (hydrogen content) in the insulating oil that changes in response to vacuum interrupter failures. By monitoring this single chemical parameter rather than multiple physical parameters, the system achieves high measurement precision for failure detection while keeping the measurement system relatively simple. The hydrogen content serves as a sensitive indicator that directly correlates with vacuum interrupter health status.

Inventive Principle:
Principle #35Parameter 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

This approach effectively detects vacuum interrupter failures, preventing potential catastrophic events by allowing for timely maintenance and reducing the risk of unnecessary shutdowns, thus ensuring the reliability and safety of transformer systems.

Implementation Method 1

repeatedly measuring a hydrogen content in the oil of the housing of the tap changer

Methodology Applied
Scientific EffectHydrogen measurement:

Implementation Method 2

at least one vacuum interrupter (MVI, RVI) arranged to interrupt a current through the movable contact of the diverter switch

Methodology Applied
Scientific EffectVacuum interruption:

Implementation Method 3

The oil in the tank acts as electric insulator and as a coolant to remove the generated heat in the OLTC

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

The oil will also quench the arcs generated during switching

Methodology Applied
Scientific EffectArc quenching:

Implementation Method 5

The arcing during the operation of the OLTC will pollute the insulating oil and wear the switch contacts

Methodology Applied
Scientific EffectArc generation: Electric Arc

Data Source

PatentEP2443641B1Method and device for detecting failure of a vacuum interrupter of an on load tap changer
Publication Date: 2014.12.17 ABB TECHNOLOGY LTD
  • EP2443641B1 patent drawingFigure 1~2c
  • EP2443641B1 patent drawingFigure 2d~3f
  • EP2443641B1 patent drawingFigure 3g~4

AI summary

A method for detecting failure of a vacuum interrupter in an on load tap changer, wherein the tap changer comprises; an oil filled housing, a diverter switch including a movable contact (MC, RC), and at least one vacuum interrupter (MVI, RVI) arranged to interrupt a current through the movable contact of the diverter switch, The method comprises; repeatedly, - measuring a hydrogen content in the oil, and - determining whether there is a failure in the vacuum interrupter (MVI, RVI) based on the measurement of hydrogen content in the oil.