Methods for Metal Screens Bonding of High Voltage Cable Lines

This article considers issues related to the design and operation of high voltage underground cable power lines. Perhaps one of the most important characteristics determining the operational performance of cable power lines is related to the adopted method of grounding the metallic screens (also called sheaths) integrated in the cable construction. Currently existing earthing methods include: single-point bonding, both-end bonding and earthing of the cable screens by transposition (crossing the screens of the individual phases of a given cable power line). Additional methods also can be adopted using the combination of the above - for example, the use of single-point bonding of the metallic cable screens for a given section of a cable power line, combined with the transposition of the screens for the remaining sections. In practice, the term cross-bonding is often used for the transposition of the cable screens for the individual phases. This method has a wide application nowadays. Cross-bonding technology for the cable screens can be performed in two ways – using continuous transposition or by sectioned screen transposition.