Elongation of overhead line conductors under combined mechanical and thermal Stress

Michael, M.; Stephan, Peter; Stefan, J.

doi:10.1109/cmd.2008.4580375

Cited by 8 publications

(6 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This was derived from the temperature limit of the specific device. Permanent damage occurs wherever the energy exposure level or the let-through energy exceeds the short time withstand rating of the conductor [33]. The energy exposure of an overhead line is defined by Equation 1 [34,35].…”

Section: Methods 21 Test Setupmentioning

confidence: 99%

Recloser based energy exposure assessment of a distribution network

Thomas

Zyl

Naidoo

et al. 2019

J. energy South. Afr.

View full text Add to dashboard Cite

The optimised placement of reclosers on a distribution network is known to improve the reliability of a power system. Furthermore, the protection settings on distribution systems rely heavily on the number and placement of such reclosers. This study examined the effect of using protection settings methodology with the placement of reclosers to ameliorate the damage sustained during faults on a distribution network. The aim of the study was to determine whether this ‘damage control factor’ should be a future consideration for recloser placement. It has been found that the determination of the number and placement of reclosers, which are the function of the energy exposure of feeder, helped to optimise the operation and reliability of a distribution network. This could benefit both energy users and energy suppliers, who often face different challenges during the fault levels on the network.

show abstract

Section: Methods 21 Test Setupmentioning

confidence: 99%

Recloser based energy exposure assessment of a distribution network

Thomas

Zyl

Naidoo

et al. 2019

J. energy South. Afr.

View full text Add to dashboard Cite

show abstract

“…The value of the mechanical tension varies with the age of the conductor material. The sag-tension tables of the same power line will be different at the time of installation and at the time of the scanning after several years of the operation [35][36][37].…”

Section: Determination and Prediction Of The Conductor Elongation Due To The Metallurgical Creepmentioning

confidence: 99%

Advanced Power Line Diagnostics Using Point Cloud Data—Possible Applications and Limits

2021

View full text Add to dashboard Cite

The advance in remote sensing techniques, especially the development of LiDAR scanning systems, allowed the development of new methods for power line corridor surveys using a digital model of the powerline and its surroundings. The advanced diagnostic techniques based on the acquired conductor geometry recalculation to extreme operating and climatic conditions were proposed using this digital model. Although the recalculation process is relatively easy and straightforward, the uncertainties of input parameters used for the recalculation can significantly compromise such recalculation accuracy. This paper presents a systematic analysis of the accuracy of the recalculation affected by the inaccuracies of the conductor state equation input variables. The sensitivity of the recalculation to the inaccuracy of five basic input parameters was tested (initial temperature and mechanical tension, elasticity modulus, specific gravity load and tower span) by comparing the conductor sag values when input parameters were affected by a specific inaccuracy with an ideal sag-tension table. The presented tests clearly showed that the sag recalculation inaccuracy must be taken into account during the safety assessment process, as the sag deviation can, in some cases, reach values comparable to the minimal clearance distances specified in the technical standards.

show abstract

“…However, CIGRE reported that not only external factors such as temperature and mechanical loading of the conductor but also internal factors such as chemical composite and geometrical formation of strand wire contribute to permanent elongation [41]. Moreover, a conductor with a high steel wire-to-aluminum ratio will have a higher strength and can delay the elongation process [134].…”

Section: ) Elongation and Creepmentioning

confidence: 99%

Review of Thermal Stress and Condition Monitoring Technologies for Overhead Transmission Lines: Issues and Challenges

et al. 2020

View full text Add to dashboard Cite

The overhead transmission line system is one of the methods of transmitting electrical energy at a high voltage from one point to another, especially over long distances. The demand for electrical energy is increasing due to the increase in the world population, the evolution of transport technology, and economic expansion, thereby resulting in overloading to the overhead line (OHL) system. In building new infrastructure for transmission lines, several issues need to be addressed. Thus, optimizing existing power by increasing the ampacity of power line is a practical solution to meet energy demand issues. During long-term operation, the temperature of OHL conductors may increase beyond their rated temperature, which is typically 75 °C for conventional conductors such as aluminum-conductor steel-reinforced cable. This condition is defined as thermal stress, which results in lower sag vertical clearance, tensile loss, elongation and creep, and reduced life span of the conductors. This condition must be avoided to ensure that the line is not permanently elongated, which can disrupt the vertical ground clearance, and to expand the conductor's life. Other factors such as lightning, wildfire, aging, and degradation of the conductor can also cause thermal stress on the conductors and have thermal effects on the conductor's performance. Therefore, unwanted thermal stress needs to be examined and identified by monitoring the thermal effect and behavior of the lines. This paper presents the state of the art in monitoring technologies that can be used to identify thermal stress on OHL conductors, including the issues and challenges in monitoring. At the end of this paper, a few suggestions are included to address the occurrence and assessment of thermal stress in lines. Ultimately, this work may provide complete information to researchers and maintenance engineers to enable them to make better decisions on condition monitoring, operation, and maintenance of the system. INDEX TERMS Overhead transmission line, thermal rating, conductor temperature, thermal stress effect, conditioning monitoring.

show abstract

Elongation of overhead line conductors under combined mechanical and thermal Stress

Cited by 8 publications

References 5 publications

Recloser based energy exposure assessment of a distribution network

Recloser based energy exposure assessment of a distribution network

Advanced Power Line Diagnostics Using Point Cloud Data—Possible Applications and Limits

Review of Thermal Stress and Condition Monitoring Technologies for Overhead Transmission Lines: Issues and Challenges

Contact Info

Product

Resources

About