Design Stresses and Current Ratings of Impregnated Paper Insulated Cables for HV DC

An investigation into the designs and current ratings of oil impregnated paper insulated cables for various direct voltage ratings and impulse withstand levels is described. Published information on the temperature and stress coefficients of resistivity is reviewed. Methods of calculation of the stress distribution are outlined. With the aid of a digital computer, data including the maximum screen stress at various maximum conductor temperatures have been obtained for a range of conductor sizes.