Improvement in Cable Rating Calculations by Consideration of Dependence of Losses on Temperature

In this paper a new method is proposed that allows estimation of conductor temperature and cable losses as a function of conductor current and some parameters corresponding to the nominal loading conditions. Such parameters include cable rating and loss factors computed by the cable manufacturer for the laying conditions specified by the user. There are two major applications of the proposed approach: one relates to rating of power cables with current measurements alone and the other to the computation of the external thermal resistance with a nonunity load factor used in the Neher/McGrath approach. Both applications are examined in this paper.