Global Earthing System Characterisation of an Actual UK Distribution Network

Abstract

Defining a distribution network as a global earthing system (GES) can simplify the design requirements when adding new substations to a network. Examples often cited include cable networks in dense-urban or city-centre locations, and large industrial areas. A far greater proportion of a network may supply small towns and villages, and these are often discounted as GES due to reduced geographical coverage or lower substation density. Two small networks, fed from a common source substation, have been examined in detail to see if any GES characteristics may be observed. Comprehensive CDEGS models, validated through field-testing, are compared with results from the simplified design tool developed by UK Power Networks.