Switching Surge Test Results EHV Substation Bus Configurations

Results of an extensive switching surge test program on extra high voltage substation bus arrangements are presented. Emphasis was placed on obtaining wet positive switching surge data under careful control of laboratory and analytical procedures. Evaluations are made of the switching surge characteristics of the air gaps for a variety of EHV bus arrangements. Involved are the effects of the dispersion for large air gaps on switching surge withstand levels and ranges of absolute crest switching surge voltage values that are to be expected. The air gaps between the several arrangements tests and the EHV data from other sources are compared.