Induced sheath voltage in double circuit

In this paper, we calculated the induced sheath voltage in metallic sheath/shield of single-core cables operating in double circuit by considering influence of arrangement and phase distance; with the aim of providing optimal value of phase distance and proper arrangement to reduce the induced voltage. Five different arrangements of the cables are used to investigate the effect of a single point bonding and the double point bonding on induced voltage. Formulae for different arrangements are derived using IEEE guide to calculate induced sheath voltage. Out of five arrangements, independent horizontal and vertical arrangements have provided better results. It is found that the independent horizontal arrangement provides lesser maximum induced voltage of 132 V/km but higher overall induced sheath voltage of 64.28 V/km when compared to the vertical arrangement. The vertical arrangement has the values of maximum induced sheath voltage of 138.8 V/km and the overall induced sheath voltage of 27.79 V/km. This causes obvious decrease in the circulating current in the metal shield of the cable which makes independent vertical arrangement better than independent horizontal arrangement with respect to personnel safety. These findings can be used to suggest proper phase distance, radius of the cables and their arrangements when operating in double circuit to reduce the induced sheath voltage in metal sheath of a cable.