Switching Surge Field Tests on the Arizona Public Service 345-kV System

Switching surge field tests were performed on a 292- mile 345-kV transmission system. Switching of lines and connected transformers resulted in surges in excess of twice normal voltage under certain conditions. Trapped charge decay on the shunt compensated lines was of such duration as to have a direct influence on high-speed reclosing transients. A number of field test conditions were reproduced on a transient network analyzer (TNA), and examples of field results and TNA results are illustrated, showing very good correlation.