Modelling and analysis guidelines for very fast transients

The objective of this task force report is to provide an explanation of the phenomena of very fast transients which can occur in gas-insulated substations (GIS). The simulation of the GIS for this type of transient should be suitable for frequencies from 100 kHz up to 50 MHz. The corresponding equivalent circuits developed in previous work of CIGRE have been reported. The accuracy of the simulation of this phenomenon and verification with field measurements are given. An example of a GIS calculation with detailed input data is presented which could be used for the recalculation of the results.