Cable sheath loss analysis based on coupled line model

Power cables are playing an increasingly important role in the power grid because of the shortage of city land. The sheath loss is one of the main shortcomings of power cable. However, research on the sheath loss is limited so far because the multi-conductor model of cable lines with sheathes is difficult to build. What´ more the great varieties of the cables and sheaths arrangement add to the difficulty. The arrangements of cables and sheathes mainly include: sheath transposition, cross-bonding, solid-bonding, one-point bonding and earth continuity conductor adoption. In this paper, the sheath loss of cables with different arrangements is studied and compared (based on the coupled line model). Besides, research is also carried out to find the cable arrangement which minimizes the total sheath loss of two circuits installed in the same tunnel.