Reliability study for the refurbishment of a HV/MV transformer substation

In the main HV/MV substation of a German distribution utility, its refurbishment is upcoming. It was the objective of the presented study, to find the economic and technical optimal solution for the medium-voltage (MV) busbar-arrangement from a functional point of view. In addition to the existing configuration (double-busbar-arrangement), simplified alternatives (single-busbar- and ring-busbar-arrangement) were designed and studied by means of probabilistic reliability calculation. The results show clearly, that the simplified configurations are almost equal with regard to the provided supply reliability and also under operational aspects they cause no essential restriction. Consequently the higher investment cost of a double-busbar-arrangement cannot be justified