Acoustic Funnel Sensor Layout for Partial Discharge Noise Filtering

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Solution Overview

Problem

Existing methods for detecting electrical discharges in electrical apparatus, particularly partial discharges, are inefficient and require expensive, infrequent inspections by skilled personnel, while acoustic waves from discharges are often masked by environmental and external noise.

Innovation Solution

A sensing arrangement comprising an acoustic sensor and a signal enhancing structure with a funnel region, configured as a high-pass filter, enhances the detection of electrical discharges by filtering out unwanted low-frequency noise and amplifying relevant acoustic signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If acoustic waves are measured during infrequent inspections using expensive measurement devices, then measurement precision is improved, but productivity deteriorates and loss of time increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidinspection frequency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The sensing arrangement enables the electrical apparatus to perform self-diagnosis by continuously monitoring acoustic waves for electrical discharges. The system automatically detects and reports discharge events without requiring external inspection personnel, transforming the inspection process from a manual service requirement to an autonomous self-monitoring capability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system transitions from infrequent discrete inspections to continuous real-time monitoring of acoustic waves. The sensing arrangement operates continuously to detect electrical discharges, ensuring uninterrupted surveillance of the electrical apparatus condition, thereby eliminating gaps between inspections and enabling immediate detection of discharge events.

Inventive Principle:
Principle #20Continuity of useful action

2Measurement precision

If acoustic waves from electrical discharges are detected, then detection capability is improved, but environmental noise and external interference worsen the signal quality

Engineering Contradiction:
Improvedischarge detection capabilityVSAvoidenvironmental noise interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system extracts and isolates the specific acoustic signal characteristic of electrical discharges from the complex background of environmental noise. By focusing on the frequency range and acoustic signature unique to electrical discharge events, the system separates the target signal from interfering noise sources, enabling reliable detection despite noisy environmental conditions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sensing arrangement acts as an intermediary between the electrical discharge source and the detection system. It selectively transmits and amplifies acoustic waves in the frequency range characteristic of electrical discharges while attenuating other frequency components, effectively filtering out environmental noise and external interference before the signal reaches the detector.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If skilled staff with expensive measurement devices are deployed for inspections, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetection accuracyVSAvoidinspection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensing arrangement employs a cost-effective sensor design that eliminates the need for expensive specialized measurement equipment and highly trained personnel. The system uses affordable acoustic sensors combined with signal processing to achieve reliable detection, replacing costly inspection infrastructure with a more economical permanent monitoring solution.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The system replaces manual inspection procedures performed by skilled staff with an automated electronic sensing and processing system. The acoustic sensor combined with signal processing electronics substitutes for the human expert's auditory and analytical capabilities, eliminating the need for skilled personnel while maintaining or improving detection accuracy.

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 continuous, cost-effective online monitoring of electrical discharges with improved sensitivity and reduced interference from environmental noise, facilitating efficient detection of partial discharges in electrical switchgear.

Implementation Method 1

Electrical discharges, particularly some types of partial discharges, in electrical apparatus can cause acoustic waves. The acoustic waves are generated by short pressure pulses induced in a surrounding medium, particularly gas, by the energy release associated with the electrical discharges.

Methodology Applied
Scientific EffectAcoustic wave generation: Acoustic Emission

Implementation Method 2

The signal enhancing structure is configured as a high-pass filter with a cutoff frequency lower than 20 kHz

Methodology Applied
Scientific EffectAcoustic filtering: Filter (physical)

Data Source

PatentEP3907502B1Sensing arrangement
Publication Date: 2025.07.02 ABB (SCHWEIZ) AG
  • EP3907502B1 patent drawingFigure 1a~2
  • EP3907502B1 patent drawingFigure 3a~6
  • EP3907502B1 patent drawing

AI summary

A sensing arrangement for detection of electrical discharges in an electrical apparatus is described. The sensing arrangement includes an acoustic sensor and a signal enhancing structure with a funnel region. The acoustic sensor is positioned outside the funnel region on an apex side of the funnel region. An electrical switchgear is described. The electrical switchgear includes a sensing arrangement for detection of electrical discharges in an electrical apparatus. The sensing arrangement includes an acoustic sensor and a signal enhancing structure with a funnel region.