All Dielectric Self-supporting Fiber-optic Cables Research Articles

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.

Detection of Dryband Arcing Processes on ADSS Cable Coating

The application of all-dielectric self-supporting fiber-optic cables (ADSS) in overhead transmission lines leads to an improvement in a communication network's transmitting capabilities. The problem with ADSS cables results from reported damage to the outer coating of cables exposed to electrical, mechanical, and chemical stresses during operating conditions. This paper presents the results of investigations of discharge mechanism on the coating of ADSS cables, causing erosion processes on a cable surface. A novel method for detecting dryband arcing processes on an ADSS cable coating based on phase-resolved discharge acquisition is presented.

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.

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.