Underground power cables are frequently used for power transmission and distribution. There are several termination and joints of overhead lines and power cables in the whole transmission and distribution-network. Throughout the whole service life of a cable, it undergoes through different transient phenomena, as lightning and switching surges. Large induced voltage in the sheath may cause serious problems like an increase in the circulating current which produces excessive heat and it may start the melting process in the sheath and eventually damage the jacket of the cable. This work aims to study the impact of lightning and switching surges, travelling in the main conductor of the cable, on the sheath of a cross-bonded-power cable. The simulation study presents the profile of transient voltage buildup, in the sheath of a-three-phase 220 KV underground power cable, along its length. The simulation model of the entire cable-network with relevant parameter is made and analysis on the effects of transient is done. The region of-the cable system where impact is more is profound is observed. It is found that for lightning impulse the-voltage profile distortion is to a greater extent in comparison to the switching impulse.
Sheath voltage, Sheath current, Cross-bonded cable, Transient voltage, Lightening impulse (LI), Switching impulse (SI)
