Transmission Line Fault Location Using Delta-Sigma Wave Sampling

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Solution Overview

Problem

Existing fault locators in electrical power transmission systems require high sampling rates and complex, costly equipment to determine fault locations accurately, leading to inefficiencies and resource-intensive processing.

Innovation Solution

A method and system utilizing Delta-Sigma modulation and filtering to sample and process transmission line signals at lower output rates, enabling accurate fault location determination by measuring the time difference between traveling wave arrivals, reducing hardware and software requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a high sampling rate (above 1MHz) is used to register travelling wave arrivals, then the accuracy of fault location determination is improved, but the processing power requirement and equipment complexity increase

Engineering Contradiction:
Improvefault location accuracyVSAvoidequipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the sampling process into two distinct stages: (1) a first sampling stage that captures signals at a high rate sufficient to resolve travelling wave arrivals, and (2) a second sampling stage that operates at a lower rate for routine monitoring. This segmentation allows the system to achieve high measurement precision when needed while reducing overall processing burden and equipment complexity through the lower-rate second sampler.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If a high sampling rate (above 1MHz) is used to register travelling wave arrivals, then the accuracy of fault location determination is improved, but the processing power requirement increases

Engineering Contradiction:
Improvefault location accuracyVSAvoidprocessing power
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The patent segments the sampling process into two distinct stages: (1) a first sampling stage that captures signals at a high rate sufficient to resolve travelling wave arrivals, and (2) a second sampling stage that operates at a lower rate for routine monitoring. This segmentation allows the system to achieve high measurement precision when needed while reducing overall processing burden and equipment complexity through the lower-rate second sampler.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using the high sampling rate only when and where necessary (during fault detection events at the first sampler), rather than continuously applying high-rate sampling throughout the system. The second sampler operates at a lower, partial rate for routine conditions, thereby reducing overall processing power consumption while maintaining the capability for accurate fault location when required.

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If a high sampling rate is used to capture travelling wave signals, then the wave front rise time resolution is improved, but the data volume and processing requirements increase

Engineering Contradiction:
Improvewave front rise time resolutionVSAvoiddata volume
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent segments the sampling process into two distinct stages: (1) a first sampling stage that captures signals at a high rate sufficient to resolve travelling wave arrivals, and (2) a second sampling stage that operates at a lower rate for routine monitoring. This segmentation allows the system to achieve high measurement precision when needed while reducing overall processing burden and equipment complexity through the lower-rate second sampler.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using the high sampling rate only when and where necessary (during fault detection events at the first sampler), rather than continuously applying high-rate sampling throughout the system. The second sampler operates at a lower, partial rate for routine conditions, thereby reducing overall processing power consumption while maintaining the capability for accurate fault location when required.

Inventive Principle:
Principle #16Partial or excessive action

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 method allows for efficient fault location with reduced resource consumption by using lower sampling output rates and existing system components, while maintaining accuracy through time difference analysis.

Implementation Method 1

sampling signals of the transmission line, at a modulation rate, using Delta-Sigma modulation at the first location of the transmission line and at the second location of the transmission line

Methodology Applied
Scientific EffectDelta-Sigma modulation:

Implementation Method 2

filtering the signals sampled at the first location, and providing, at a first output rate, first output samples based on the filtered signals sampled at the first location

Methodology Applied
Scientific EffectFiltering: Filter (electronic)

Data Source

PatentEP4558837B1A method and a fault locator system for determining a location of a fault in a transmission line
Publication Date: 2026.04.15 HITACHI ENERGY LTD
  • EP4558837B1 patent drawingFigure 1a
  • EP4558837B1 patent drawingFigure 1b
  • EP4558837B1 patent drawingFigure 2

AI summary

A method (1000) and a fault locator system (100) for determining a location of a fault in a transmission line are provided. The method comprises determining (1001) arrival times of travelling waves at a first location and a second location, determining (1002) the location of the fault based at least on a difference between the first and second arrival times and a wave speed of travelling waves along the transmission line, sampling (1010) signals of the transmission line, at a modulation rate, using Delta-Sigma modulation at the first and second locations, filtering (1021) the signals sampled at the first and second locations, and providing (1025), at an output rate, output samples based on the filtered signals, wherein the determination of the arrival times are based on sets of the output samples, and wherein the modulation rate is higher than the first and second sampling rates.