All Dielectric Self-supporting Research Articles

Study and Analysis for the Choice of Optical Fiber in the Implementation of High-Capacity Backbones in Data Transmission

Fiber optic implementation projects for backbones today have become a necessity, where in many cases failures due to cable stress breaks have been reported. Due to this, it is necessary to carry out a study and analysis of the zone and area prior to implementation. In this research work, through a method based on theory and analysis, the geographical and climatological conditions where the optical fiber will be installed in the Lima region, Peru, will be evaluated, as well as the study of mechanical loads and electric fields associated with the installation of fiber optics on existing electrical network lines will also be carried out. The results of this study showed that for regional backbone projects in the city of Lima, Peru, the use of the type of optical fiber should be considered under the recommendation of the International Telecommunications Union (ITU) -T G.652.D All -Dielectric Self-Supporting (ADSS). The studies and results obtained in this research may also help the various companies in the sector, in future implementations of high-capacity fiber optic backbones in data transmission, to make the best decision on the type of cable and its recommended characteristics for the region.

Examination of Wind Effect on Adss Cables Aging Test

DOI: 10.5152/iujeee.2018.1818 ADSS (All dielectric self supporting) cables are generally installed on high voltage transmission lines and mostly used under different environmental effects, such as temperature, wind, UV radiation, etc. In this study, wind affect on ADSS cables was investigated by using dry band arcing (IEEE 1222 Electrical surface degradation) test method. A wind source was implemented to the test setup to evaluate the performance of PE (Poly-ethylene) cable jacket on ADSS cable under different wind speeds. Test results indicate that life time of the ADSS cable decreases while the wind speed is increasing.

Analysis of frequency characteristics of electrical arcs on the insulating sheath of the ADSS fiber optic cables

The insulating outer-sheath of ADSS (All dielectric self supporting) cables used on high voltage transmission lines are often subjected to various environmental effects. The ageing process of cable sheath can be investigated by using the dry-band arcing test method under laboratory conditions. Dry-band arcing is the most common technique to determine the ageing period of insulating materials. Environmental effects such as rain, humidity, dew and ice produce various amounts of wet regions on the cable surface. Electrical arcs and hence degradations are occurred on the cable surface due to the enhanced electrical field with formation of wet regions. In this study, the ageing process of ADSS cables was investigated by using the dry band arcing test method (IEEE 1222 Electrical surface degradation). Rainfall intensity determines the wet regions on the cable surface which affects the ageing process of the cable. During tests electrical arc signals were investigated by analyzing wet region scope versus amplitude and frequency spectrum variations via the FFT method. It is possible to claim that the proposed FFT analysis clearly identifies the ageing period of the ADSS cable which was subjected to different rainfall intensities by monitoring frequency spectrum of the arc signals.

Experimental Correlation of the Aging Process of the ADSS Fiber-Optic Cables in ASU's Environmental Chamber to Field Tests in Bandon, OR

An environmental chamber has been constructed at Arizona State University to establish a long-term aging test of all-dielectric self-supporting (ADSS) fiber-optic cable. A polymer-jacketed ADSS (track resistant) cable is subjected to UV radiation, salt fog, clean rain, and mechanical tension in the aging chamber. Installed by the Bonneville Power Administration (BPA), a similar track resistant ADSS has been in operation for about eight years, near the Pacific Ocean at Bandon, OR. Accumulated pollution on this ADSS has been measured by BPA on approximately a semiannual basis. In this paper, the aging chamber operation is outlined briefly and two methods of measuring the accumulating pollution level on the ADSS cables in the aging chamber are described. The accumulated pollution levels of both ADSS cables in the chamber and in Bandon, OR, are compared. It is noted that general chamber performance compares favorably to the field data as well as suggesting an approximate chamber-aging rate, about 18:1.

Implementation of a Solution to the Problem of Dry-Band Arcing on ADSS Cables

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The all-dielectric self-supporting (ADSS) cable offers many advantages when installing an optical fiber network on high-voltage overhead lines. Generally, the use of ADSS cables is confined to system voltage levels well below 275 kV because of the threat of dry-band arcing on the cable sheath. This limit is somewhat arbitrary since, in polluted conditions, cables can fail at much lower system voltages, and in some higher voltage installations no problems have been witnessed. A solution to the problem of dry-band arcing on ADSS cables has been proposed previously, where 50-m resistive rods are attached to the self-supporting cable after installation. The first large-scale installation of this system has been successful, and the first six years of operation is reviewed. The installation is in a particularly aggressive situation and a high level of maintenance has been found to be necessary. </para>

Prevention of dry-band arc damage on ADSS cables

All-dielectric cables separately suspended along high voltage overhead transmission routes are vulnerable to ageing through dry-band arcing. The differences between this process and dry-band arcing on traditional high voltage insulators are reviewed. Solutions to the problem on all-dielectric self supporting (ADSS) cables which involve the introduction of controlled conductivity into the cable are considered. Analysis suggests that arcs which are both electrically stable and spatially confined must be avoided. It is shown that the cable can be protected by limiting either the current or the voltage available to an arc. These considerations reveal that a semiconductive element does not have to cover the whole cable length to provide effective protection against dry-band arcing in this application

Engineering a solution to the aging of HV self-supporting cables by dry-band arcing

The retrofit rod of controlled resistivity clearly has the potential to remove the threat of dry-band arc damage on all-dielectric, self-supporting (ADSS) cables. This is achieved by reducing the maximum current available on the cable for arcing activity. Rods can be applied to polyethylene sheathed cables or arc-resistant sheathed cables and can improve the performance of both. Extensive trials in the UK have shown that the rod works and have confirmed predictions of computer models. However, the engineering of the application of such as solution is complex. Individual spans of different geometry, including cable sag, must be considered. In particular, local variation in pollution is critical; so knowledge of the proximity of the sea or industry must be considered. It is also very likely areas that do not experience much rainfall will be particularly onerous because the cable will not be naturally washed regularly, so the pollution on its surface will tend to build up, reducing its resistance in times of high humidity, fog, and dew

Development of the Dry-Band Arc on All-Dielectric Self-Supporting Cables During Laboratory Tests

Utilities frequently install All-Dielectric Self-Supporting (ADSS) fiber-optic cables on transmission lines. The cable jackets suffer damage due to dry-band arcing caused by high electric fields and pollution on the cable. A test method to determine cable resistance to dry-band arcing is being considered for standardization by the IEEE. A new nozzle arrangement for the test is proposed in this paper. Using this nozzle the repeatability of the test is significantly improved over previous arrangements. Each test cycle consists of three stages: wetting, drying, and arcing. The three stages are examined in detail. Development of the dry-band arc on the cable jacket during the arcing period is presented. It is shown that the length of the arc increases exponentially with time and reaches a stable length. The stable length is shown to be a function of the applied voltage.

Analysis of Electric Field Distribution Around the High-Voltage Overhead Transmission Lines With an ADSS Fiber-Optic Cable

This paper is an analysis of electric-fields distribution around overhead transmission lines (OHTLs) with an all dielectric self supporting (ADSS) fiber-optic cable. The aim of this analysis is to determine electrical interactions on a fully dielectric cable located in the electric field of OHTL. Two characteristic areas were taken into consideration. The first of these-in the middle of the line span, and the second-around the clamps which fit the cable to the transmission line tower. These areas follow from localization of ADSS-type cable in the line span. The latter of this area was taken into detailed analysis for determining the conditions of electric discharge initialization on the cable's surface.

Communications technology guidelines for EMS/SCADA systems

The purpose of this Guideline Technical Paper is to provide a summary of the different communications technologies available for use or application with EMS/SCADA system projects. All of the various communication media are addressed with a brief description along with tables of the advantages and disadvantages of each and recommendations for choosing the most appropriate communication technology. The technologies discussed are: twisted pair metallic cable; coaxial metallic cable; fiber optic cable (either optical power ground wire (OPGW), all dielectric self supporting (ADSS), or wrapped types (WOC)); distribution line carrier (DLC); power line carrier (PLC); satellite (VSAT, LEO, others); leased service; VHF radio (mobile); point-to-point UHF radio; multiple address radio system (MARS) 400/900 MHz UHF radio; trunked mobile UHF radio; spread spectrum UHF radio (monitor frequency for potential interference before installation); and microwave radio (2-40 GHz).

Algorithm to predict dry-band arcing in fiber-optic cables

Utilities frequently use ADSS (all dielectric self-supporting) fiber-optic cables installed on transmission lines 3-6 m below the high voltage conductors. Dry-band arcing occurs on the fiber-optic cables when the cables are polluted and wet. This has been assumed to cause cable failures. An equivalent circuit has been developed to represent the polluted fiber-optic cable in the high voltage environment. The objective of this paper is to present a novel numerical method that can be used to predict dry-band arcing in fiber-optic cables. KCL (Kirchoff's current law) is used to derive node point equations for the equivalent circuit. Forward elimination and backward substitution of node voltage is used to solve the equations. The effect of pollution, tower arrangement, and conductor sag is analyzed. The numerical method has speed advantages over circuit simulation methods. This method includes conductor sag, nonuniform pollution, and variable capacitance. This algorithm can be used to predict dry band arcing in fiber-optic cables.

Damages and destruction of fiber optic cables on 161 kV overhead transmission lines

All-dielectric self-supporting (ADSS) fiber optic cables are in use now on high-voltage (HV) and extra-high-voltage (EHV) overhead transmission lines (OHTL) in many countries all over the world. Their use allows the creation of highly effective data communication channels along the OHTL. However, in subtropical areas with specific climatic conditions, dry-band partial arcs have been found on the polyethylene external protective enclosure cable surface. This paper describes the various investigations performed to understand the causes for damage to ADSS fiber optic cable installed on four 161 kV OHTL and on one 110 kV, in the subtropical climate of Israel.

Electrical design parameters of all-dielectric-self-supporting fiber optic cable

A lumped circuit model for calculating voltages and currents on all-dielectric self-supporting (ADSS) fiber optic cable near high voltage transmission lines has been developed. The model has been used to show that contamination levels, tower attachment points, relative ADSS and conductor sag and electrical phasing of the conductors are important parameters and must be considered in calculations, especially when determining the possibility of dry band arcs which could lead to cable damage.

On the measurement of overhead transmission lines conductor self-damping

This work is about a new methodology for determining the overhead transmission line (OHTL) conductor self damping by means of tests on a laboratory span. The method proposed relies on the inverse standing wave ratio (ISWR) method, but introduces a measurement procedure in condition to limit some of the problems connected to the straight-forward application of the method. It has been studied and tested especially in view of its application to the measurement of the self-damping of particular conductors, such as the optical ground wires (OPGW) and the relatively new all dielectric self supporting (ADSS) optical cables, whose self-damping is very low. A comparison with the results obtained by means of other methods for determining the conductor self damping is presented too.

Corona caused deterioration of ADSS fiber-optic cables on high voltage lines

Summary form only as given. Deterioration of ADSS (all-dielectric self-supporting) fiber optic cable jacket material has been reported near the tips of armor rod assemblies installed on high-voltage transmission lines. Field observations and laboratory tests revealed that corona can exist on the tips of the armor rod. Electric field analysis reported herein reveals that the tip surface gradients are high enough to produce corona. Field conditions have been duplicated in a high voltage test chamber and jacket damage has been observed near generated corona. The deterioration mechanism is identified and jacket life expectancy is estimated. Different mitigation techniques are suggested.

An improved model for the electromagnetic compatibility of all-dielectric self-supporting fiber-optic cable and high-voltage power lines

It has become common for utilities to locate optical-fiber communication systems on their transmission line towers. One type of cable used for this purpose is all-dielectric self-supporting (ADSS) cable, which is usually located below the phase conductors. Cables of this type have failed because of exposure to high electric fields. In this paper, a model is developed which can be used to establish the conditions for failure-free operation of ADSS cable.