Study On Limiting Measures Of Metallic Sheath Induced Voltage Of Single-core XLPE Power Cables

Security layer insulation damage of single-core crosslinking xlpe power cables is the main reason why cable line fault occurred in 110 kv and above, and cable security layer insulation damage caused by cable security layer overvoltage already accounted for more than 50%. Correct analysis of generating mechanism of inductive voltage cables security layer, accurately calculating various operation conditions of inductive voltage cables security layer, proposing limiting and protective measures being suitable for engineering practice, has important significance to ensure the safe and stable operation of cable.In this paper, the generating mechanism of security layer inductive voltage of single-core crosslinking xlpe power cables is made a thorough theoretical analysis. It has calculated separately cables security layer inductive voltage under the action of impulse voltage and power frequency voltage. Important factors that affect the cable security layer induced voltage have been found, namely the length of cable, the current through cable and cable arrangement. It comes to the conclusion that the value of cable security layer induced voltage is proportional to the length of cable line and the current flowing through cable.Through theoretical analysis and calculation to sheath layer wiring and grounding, it is concluded that the wiring way of cable security layer can restrict security layer inductive voltage. Aiming at different circumstances of cable line in engineering practice, it can adopt different wiring and grounding methods of cable security layer to limit the security layer induced voltage. It also analyzes the important role of security layer protector in protecting security layer outer insulation. Comparing the two wiring methods of security layer protector, it is to summarize that Y connect method is more reasonable and practical than the previous Y0 wiring method.It introduces the practical application of cable security layer cross interconnected wiring way using in Inner Mongolia drum - led 110kv line, and illustrates application effect. Furthermore, it proved that measures to limit cable security layer induced voltage are effective, complying with engineering practice...