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Fault Detection Using Fiber-Optic

In electric power supply services, power transmission lines are very important and very indispensable. For that, power transmission lines are equipped with various protection systems that are checked varies times periodically because of the unexpected troubles that may destroy the lines.

Causes and effects of faults in overhead transmission lines
Causes and effects of faults in overhead transmission lines

For the purpose of protecting these lines, a new system was invented to discover the Fault Location using Composite Fiber Optic Overhead Ground Wire (OPGW). This system deals mainly with most causes of fault situations such as lightning, dew, snow, fog, or gales. This new fault location system was developed to find out where electrical fault happened on overhead power transmission lines by detecting the current induced in the ground wire.

Any fault situation needs the fastest processing in fixing the fault. For that, the fault location system helps engineers to detect the point or the section where an electrical fault happened in very logic time.

Since the fault information is uncertain, the new fault location deals with the fault information as a current distribution pattern throughout the power line, and applies Fuzzy Theory to realize the human-like manner of fault used by power engineers.

Mainly, the fault location method measures the current induced in the OPGW at many points along the line, these points are various sensors mounted on the tower and transmits the information to the central monitoring station through the optical fiber within the OPGW. So the fault information system is mainly given by sensing and data transmission.

Electrical faults occurring on power transmission lines can be classified into two types: grounding and short circuit fault. The transmission that gets to the central monitor station deals with current characteristic features. In order to locate the fault, engineers must use the features of currents that deal with the phase angle and the amplitude and relate these features to Fuzzy Theory.

The idea arose of using Fuzzy Theory as a fault theory algorithm similar to this kind of human thinking.


Fault Detection Using Neural Network

As indicated before, protecting transmission is very important task in safeguard electric power systems. For that, faults on transmission lines need to be detected, classified, and located accurately. All these actions must be taken in very short time to clear the fault.

The new approach of neural network to fault classifications for high speed protective relaying is a good manner in solving any fault classification for high speed protective relaying is a good manner in solving any fault happened to the transmission lines.

The functional parts of protective relay
Figure 1 – The functional parts of protective relay

Mainly this scheme is based on the use of neural architecture and implementation of digital signal processing concepts. Figure 1 shows functional parts of protective relay.

The protective relay need sampled values of currents and voltages of three lines build inputs of the system.

In general, a knowledge control module controls all other parts of the relay and is responsible for sending trip signals. The fault detection module is signals that a fault location classification module uses samples of normalized currents (i) and voltages (v). A 1 KHz sample rate is use to ensure that the fault type classification can be done in a timely fashion.

This module classifies weather a 1-phase-to-ground, 2-phase-toground, phase-to-phase or a 3-phase fault has occurred.

In the classification process, arcing and non-arcing must be known in order to obtain a successful automatic reclosing. Generally speaking, neuTral network classifies the fault into types. The first type (1-phase, 2-phase, 3-phase faults) is fast 5-7 ms and reliable.

The second type, arcing and non-arcing faults support a successful automatic reclosing.

Title: Causes and effects of faults in overhead transmission lines – William Patrick Davis at Department of Electrical and Electronic Engineering, California State University, Sacramento
Format: PDF
Size: 2.5 MB
Pages: 75
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3 Comments


  1. J A TRivedi
    Sep 13, 2019

    Dear Sir, all articles r very useful, and also I request you to publish the articles about smart grid and smart meters


  2. Chellachamy N
    Sep 11, 2019

    It is really an useful article
    It will be very useful to the
    EHT lines maintenance troupe
    I am really interested in this field


  3. Mario Valenzuela
    Sep 10, 2019

    Felicitaciones, muy buen tema !!!

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