Equivalent Circuits of Transformers and Reactors to Switching Surges

Effects of lightning-arrester characteristics and location upon protection

“…At the receiving end of the line, valve lightning arresters were used to protect various combinations of capacitors representing a transformer and accessory station equipment under surge conditions. 1 This test was used to represent a surge entering a l l 5-kv station over a line with one mile of overhead ground-wire protection. With the line terminated in its characteristic impedance of 450 ohms, the surge delivered into the line was negative 650 kv, 0 .…”

“…The transformer was always represented by a 3,100-micromicrofarad capacitor. 1 Accessory equipment (circuit breakers, and so forth) was represented by 213and 1,000-micromicrofarad capacitors. The test surge was a full wave of crest value slightly below that which would spark over representative 115-kv line insulation.…”