Transformer Partial Discharge Sensing With UHF Position Localization

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Solution Overview

Problem

Existing methods for detecting and locating partial discharges in transformers are inefficient, requiring multiple sensors and costly shutdowns, and existing ultrasonic and ultra-high frequency signal methods are not accurate enough.

Innovation Solution

A device with an omni-directional and directional ultra-high frequency sensor, along with a light sensor, is installed in a transformer's drain valve, allowing for high-accuracy detection and localization of partial discharges without shutting down the transformer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual inspection or experience-based methods are used to find partial discharge position, then inspection can be performed, but the transformer must be stopped and insulating oil drained, causing significant time and cost loss

Engineering Contradiction:
Improvepartial discharge position detection capabilityVSAvoidtransformer downtime
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces mechanical inspection methods (visual inspection requiring opened transformer and drained oil) with electromagnetic field-based sensing. UHF sensors detect partial discharge signals through the transformer tank wall without mechanical access, and electronic signal processing locates the discharge position, eliminating the need to stop the transformer and drain oil.

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

2Measurement precision

If four or more sensors are installed inside the transformer for highly accurate position measurement, then measurement precision improves, but device complexity and installation cost increase

Engineering Contradiction:
Improveposition measurement accuracyVSAvoidnumber of sensors required
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the sensors from the transformer interior and mounts them on the external tank surface. This allows accurate position measurement using fewer sensors (typically 2-3 external sensors suffice) compared to internal installation, simplifying the device while maintaining or improving measurement precision through external electromagnetic signal detection.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If ultrasonic signals are used for partial discharge detection, then detection can be performed in operating transformers, but the signal level is low making position measurement difficult

Engineering Contradiction:
Improvedetection capability in operating transformersVSAvoidposition measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent changes the detection frequency parameter from ultrasonic (lower frequency) to ultra-high frequency (UHF, 300-3000 MHz). UHF signals have higher energy and better penetration characteristics, providing stronger signal levels for position measurement while maintaining the ability to detect partial discharges in operating transformers through the tank wall.

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

Enables rapid identification of defective parts, minimizing downtime and costs by accurately locating partial discharges in operating transformers, thereby preventing accidents.

Implementation Method 1

a method of estimating the location of the partial discharge using ultrasonic or ultra-high frequency signals in an operating transformer has been proposed

Methodology Applied
Scientific EffectUltra-high frequency signal detection: Electromagnetic Induction

Implementation Method 2

a third sensor disposed within the case and detecting light within the transformer

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Data Source

PatentEP4671776A1Device for sensing partial discharge of transformer
Publication Date: 2025.12.31 HD HYUNDAI ELECTRIC CO LTD
  • EP4671776A1 patent drawingFigure 1
  • EP4671776A1 patent drawingFigure 2
  • EP4671776A1 patent drawing

AI summary

The present invention relates to a device for sensing a partial discharge of a transformer, the device detecting a partial discharge in a transformer and being capable of measuring the position thereof. The device for sensing a partial discharge of a transformer, according to one embodiment, may comprise: a case which is provided in the transformer and which has a hollow portion; an omni-directional first sensor which is disposed at one side in the case and which detects a partial discharge signal of the transformer; and a directional second sensor which is disposed at the other side in the case and which detects the partial discharge signal of the transformer.