Experimental investigation on air breakdown under lightning impulses with various electrode configurations

This paper describes sparkover characteristics of air. Standard lightning impulse of 1.2/50 is used in this study, along with three different electrode configurations. It is found that U50 and Emax increase with air pressure, particularly in larger gap lengths, with tests being carried out up to 0.25 MPa (abs). It is also found that higher gap lengths provide higher U50 and Emax for a given electrode configuration. A non-uniform field configuration provides very high electric field upon breakdown, whereas a more uniform field configuration provides higher breakdown voltage level.