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Optical systems and Optical Fiber Sensors offer a decisive solution to monitor critical parameters in presence of high electromagnetic interferences as in the case of the T&D network. These sensors can operate safely and, therefore, they are suitable for integration and security application to on-service electrical equipment. In this work we report some examples of RSE optical systems and sensors...
The mathematical model for calculating conductor temperature of overhead transmission line (OHTL) has been developed in this paper. This model is able to calculate conductor temperature for real meteorological conditions. Also it can be used for calculating temperature in case that electrical current which flows through conductor is produced using wind turbines. Using this model the critical conditions...
This paper deals with the influence of changes in transmission line maximum conductor temperature and load current depending on conductor type and climate conditions. The theoretical backgrounds of the allowable conductor temperature as well as load current determination principles are proposed. The simulation tasks were based on a specific line model. The results of the obtained data are presented.
With the development of power and extreme weather increasing, icing of transmission lines caused a series of accidents whose harm and impact also expanded. In this paper the ice-prone areas and its influence were described. At the same time icing conditions and the main types of icing were analyzed. Finally the research of icing at home and abroad was proposed. Several typical schemes for the prevention...
Lightning performance of distribution line is an important issue in the countries with high lightning density such as Malaysia. Many studies have been carried out to investigate the lightning performance and thus protect the overhead line from this overvoltage. This paper presents the line performance sensitivity studies of a special 33kV line underbuilt on transmission structure by mean of line arrester...
In electric field generated by ultra high voltage overhead lines, electric charges are induced at surface of human body. These electric charges alter electric field of human body and adjoining space. In order to study the influence of human body, a human body model is placed under ultra high voltage overhead lines and electric field produced by the overhead lines is calculated. Charge simulation method...
The problem of massive electricity transmission is addressed here by presenting some alternatives for optimizing the power transfer capacity of existing Overhead Line Systems (OHL). Some results from a hypothetical case study of a British lattice tower OHL system under re-conductoring and implementation of new composite cross-arm technology are presented. Analysis involves sag, ampacity, and insulation...
The detection system in substation of medium voltage overhead line can mostly detect only low impedance fault, neither broken conductor on the source side with high impedance, nor broken conductor on the load side with even direct to ground. This paper presents novel method to characterize such faults using time shifting in 3 phase line current. It can be applied, however, in parallel with the conventional...
This paper presents a concept to reduce the magnetic field generated from ac overhead transmission lines. The mitigation of magnetic field is performed by using a passive loop conductor. The method is applied to a flat transmission line configuration which is used frequently in extra high-voltage system. The effect of width and height of passive loop conductor on the reduction of magnetic field intensity...
The objective of this paper is to contribute with the researches on the mapping of the electromagnetic fields of transmission lines using the Charge Simulation Method and MATLAB to develop a software that is capable of measure the electromagnetic fields of transmission lines. The software has several different analyses for the electromagnetic fields, which include the electromagnetic graphs, the 3-D...
Conductor, which is in the condition of aeolian vibration for long period, will transfer vibration to the composite insulator, so composite insulator is frequently subjected to vibrational fatigue failure. This paper takes a 500kV transmission line for example, calculates the max dynamic bending stress of wire clamp exit, and gets the vibrational load values, which are caused from conductor aeolian...
Icing of high-voltage overhead power lines can affect the safe operation of the power distribution grid due to the additional weight load of the accumulated ice layer. Monitoring and predicting of icing enable its removal at an early stage. In this paper, we present the first field test results of a capacitive icing detector powered by a capacitive energy harvester on a 220 kV overhead power line...
Due to the economic pressures of internationalized energy market together with rising demand for electrical power, a growing need has been observed in recent years to increase ampere capacity (ampacity) of high voltage overhead transmission line infrastructure. Long construction time, difficult legal procedures and cost considerations encourage the line operators to exploit the wide margins of the...
Galloping is a major impact on the design of overhead transmission lines and has caused various kinds of structural damage. With rapid development of construction content and scale for China grid and with frequent appearance for worse severe weather in recent years, galloping accidents of iced conductors are becoming more frequent in China, which has caused severe economic losses and social impacts...
The conductors swinging out of sync caused by wind is a common phenomenon on overhead transmission lines, especially in the coastal zone the wind is usually very strong, and conductors non-synchronous swinging is also very severe. Many examples of power system failure were caused by conductor swinging out of sync in recent years. The study of conductor swinging out of sync becomes a hot topic in China...
Over the last five years, several research teams around the world have been developing concepts, lab prototypes and control algorithms dedicated to transmission line inspection robots. Most have not progressed to actual field testing, far less use on live lines for inspection or maintenance tasks. One exception is LineScout Technology, developed by Hydro-Québec's research institute. The video presents...
The new technology proposed is to use multiple machines in synchronization, pulling multiple draw wire ropes each one connected to one or more conductors in transmission stringing equipment capable of bundle multiple conductors (2,4,6,8) stringing processes without creating impact on the maneuverability of machinery whilst providing machinery with diversity for any size project. The solution consist...
Condition monitoring of overhead electricity transmission line assets is essential to network operation. Traditionally, the condition of overhead lines are assessed visually. Visual inspection is difficult to apply to phase conductors due to their height above ground. As such, aerial imaging surveys seem to be an ideal solution to this problem. However, the large number of high resolution images generated...
This paper presents a new robot prototype for the construction of Hydro-Québec's overhead distribution lines. It details the main sub-systems of the robot, such as the climbing system (for climbing poles), the crossarm manipulation system (which handles crossarms and selects tools for drilling holes and inserting bolts), and the bolting system (for fixing crossarms and braces on poles). The robot...
Ice accumulated on conductor in transmission line can cause severe damage to the network. Various de-icing methods are introduced in details. According to the types of transmission lines, ice melting methods are classified into ac line de-icing and dc line de-icing. Different methods are described as many as possible. Then advantages and disadvantages of various de-icing methods are compared and the...
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