110kV high voltage cable sheath transposition to reduce the grounding induction currents

Abstract

Abstract When the high voltage cable core passes through the alternating current, the metal sheath will produce induction electricity under the action of electromagnetic induction. When the sheathes are grounded, the induced currents will reduce the transmission capacity of the wire core and increase the power loss. This paper firstly introduces the grounding mode of cable sheath, and then analyzes the grounding mode at both ends of the sheath and the induced current of cross-connected grounding through ATP-EMTP software simulation. The results of the research have shown that: when the cables are in normal operation, the sheathes adopt cross-connected grounding, the induced currents are reduced, and the energy loss caused by induced currents can be neglected. In actual engineering, due to the non-uniform length of each section of cables, when the cable sheathes are cross-connected, there will be residual positive and negative sequence current in each phase of the sheath after complete transposition.