Transient heating of buried power cables

Abstract

SynopsisAn account is given of past work in the field of thermal transients in buried cables. From the publications of Morello and Van Wormer, it follows that the earliest simplified theoretical formulas for the conductor transient, produced for application to small-diameter cables, can be correct only for times sufficiently large for the effect of the thermal capacity of the cable to be negligible. For such large times, the simple exponentialintegral formula is shown to give a cable-surface attainment factor that is closer to the solution of the proposed model of Whitehead and Hutchings than is the more complicated Whitehead-Hutchings formula itself, although the difference is generally negligible. A comparison is given between the cable-surface attainment factor based on a constant rate of heat flow from the cable to the soil, and the corresponding exponential-integral formula.

Power Cable Rating Calculations - A Historical Perspective [History]

“…This historical document was developed in collaboration with leading experts from the United Kingdom, The Netherlands, France, Germany, Italy, and the United States and represents the first attempt at an international harmonization of cable rating methods [42]. Weedy (1962) [ Some years later, in [43], Goldenberg reported a summary of past works in the field of thermal transient studies on buried cables. This paper focuses on the thermal resistance of the buried cable surrounding and presents a comparison of the results calculated by means of the exponential integral formula with other results obtained by the approaches of [23] and [39].…”