Development and feasibility analysis of insulation support arms for compact power pylons

Due to many reasons, like digitalization, electrification and the switch to renewable energy sources, power grids will have to be rethought in the coming years and decades. Therefore, the power grids must be significantly expanded and rebuilt. However, approval procedures are time-consuming not least because of resistance from farmers' associations and citizens' initiatives against overhead lines. As underground cables also deal with many issues and are expensive in relative terms, compact power pylons could be a way to overcome this problem. For this reason, a new concept, the composite power pylon was investigated within the EU funded project “European Composite Pylon”. Main innovation is the support arms, that are electrical insulating. This enables the attachment of conductor bundles and earth wires directly to the support arms, thus saving height that are conventionally needed for electrical insulation. This paper gives an insight on designing and full-scale testing of insulation support arms for a 420 kV power pylon, carrying three conductor bundles and an earth wire. Within the project also three full-scale power pylons were erected in Denmark.