Improved calculations for external clearances on overhead lines
EN 50341-1 is applied for the design of overhead transmission lines and their insulators. This document has National Normative Appendixes with specific deviations and additions per country. The Dutch TSO is in the process of designing a new standard line configuration and has performed a review of the calculation approach for external clearances. This review identified some issues with the present EN 50341-1 calculation approach. It also identified the need for a more detailed method to be followed in the Netherlands, because of the extremely long insulators used to cope with the high insulator contamination levels.