The IRMA Community
Newsletters
Research IRM
Click a keyword to search titles using our InfoSci-OnDemand powered search:
|
Sheath Overvoltage Due to External Faults in Specially Bonded Cable System
Abstract
In chapter 10, It is shown that the types of the bonding are one of the important factors which affect the sheath losses in single-core cables, and it is concluded that both single-point bonding and cross bonding, which are known as special bonding, introduce the lowest losses in the metallic sheath of the cable. To take the advantages of the specially bonded cable systems it is necessary to insulate the cable sheath from earth to avoid corrosion. This is achieved by having an extruded serving of PVC or PE on the cables and housing the joints in compound filled fiberglass boxes to insulate them from the surrounding soil. The use of special bonding gives rise to sheath over-voltages at sheath sectionalizing insulators in cross bonded cable system and insulators in a single-point bonded cable system due to lightning, switching surges or faults. One of the factors affecting the sheath losses in single-core underground power cables in case of special bonding types is the sheath overvoltage. Those over-voltages may cause the sheath multi-points break-down which result in a large sheath currents and losses and hence may cause overheating of the cables and finally leading to operation faults. As mentioned before, faults are one of reasons which cause sheath over-voltages. System faults may be divided into internal faults occurring within the cables themselves and external faults for which the cables carry some or the entire fault current. The sheath voltages resulting from internal faults may greatly exceed those caused by external faults. A fault in the cables themselves inevitably involves repair work and hence it is not so important if the sheath insulation adjacent to the fault is also damaged. The sheath bonding design should preclude the damage cascading to other parts of the cable system i.e. the cable installation must clearly be capable of safely withstanding the effects of any fault in the system external to the cables . So it is important to consider the performance of special sheath bonding methods in relation to power frequency external fault currents.
Related Content
|
B. Neeraja, Darshan Pradeep Pandit, Nagamani Molakatala, Kalpana Chittor S., Ankita Tiwari.
© 2024.
26 pages.
|
|
Priyanka Gupta, Shikha Shikha, Monica Bhutani, Jyoti Gupta, Monica Gupta.
© 2024.
31 pages.
|
|
B. Neeraja, Warshi Singh, K. Arulini, V. Krishnamoorthy, Somu Chinnusamy.
© 2024.
26 pages.
|
|
Kamalendu Pal.
© 2024.
15 pages.
|
|
Mallireddy Naresh, D. Abdus Subhahan, Vivek Narula Narula, Dayana K. Roslin, Shaweta Narula, Sampath Boopathi.
© 2024.
29 pages.
|
|
Suriya Ponnambalam, Ilampoornan M. K..
© 2024.
29 pages.
|
|
Adireddy Ramesh, N. Hemalatha, Satyendra Vishwakarma, G. S. V. Seshu Kumar, Vellayan Srinivasan, M. Sudhakar.
© 2024.
22 pages.
|
|
|