A Review Method of Calculation Results on Cable Ampacity using the Transformation to Electric Equivalent Circuit from Cable Thermal Circuit

Title & Authors
A Review Method of Calculation Results on Cable Ampacity using the Transformation to Electric Equivalent Circuit from Cable Thermal Circuit
Kang, Yeon-Woog; Kim, Min-Ju; Jang, Tae-In; Park, Jin-Woo; Park, Hung-Sok; Kang, JI-Won;

Abstract
Current rating of a power cable can be calculated by the maximum allowable temperature in an insulating material considering the heat transfer from cable conductor. Therefore, it is very important to calculate the current rating using electrical equivalent circuit by calculated cable thermal circuit parameters but, it has not been fully investigated yet. In this paper, in order to determine the current rating of power cable, conventional calculation method has been reviewed considering the conductor resistance, loss factor of sheath, dielectric losses and thermal resistances based on the maximum allowable temperature of 345 kV $\small{2500mm^2}$ XLPE cable. To confirm the calculation result of the current rating, the conductor temperature should be examined whether it reaches the maximum allowable temperature by the thermal equivalent circuit of the cable. Then, utilizing EMTP (Electro-Magnetic Transient Program) which is a conventional program for electrical circuit, the thermal equivalent circuit was transformed to an electric equivalent circuit using an analogous relationship between thermal circuit and electrical circuit, and temperature condition including cable conductor, sheath, cable jacket could be calculated by the current rating of 345 kV $\small{2500mm^2}$ XLPE cable.
Keywords
Cable;Thermal circuit;Electrical equivalent circuit;Ampacity;
Language
Korean
Cited by
References
1.
Neher, J. H., and M. H. McGrath. 1957. "The Calculation of Temperature Rise and Load Capability of Cable systems". AIEE Transactions on Power Apparatus and Systems. Vol. 76. October.

2.
IEC 60287, "Electric cables - Calculation of the current rating", 2006.

3.
IEC 60853, "Calculation of the cyclic and emergency current rating of cables", 2006.

4.
EPRI Underground Transmission Systems Reference Book, 2006 Edition, EPRI