Flashover Characteristics of Extremely Long Gaps in Transformer Oil under Non-Uniform Field Conditions

Flashover characteristics of rod-rod and rod-plane electrode configurations in transformer oil are studied for extremely long gap lengths in the range of 150 to 1000 mm under conditions of lightning impulse, switching impulse, and alternating current voltages. The relation between flahsover voltage and gap length and the polarity reversal effect for switching impulse voltages are described in detail.