Methods for predetermining corona losses
Crown effect on overhead power lines

When the voltage at which a conductor is connected is gradually increased, the corona effect appears suddenly only if the conductor has a perfectly smooth, clean surface (surface condition coefficient m = 1). Measurements carried out on experimental lines show that corona losses appear at voltages well below the critical voltage, i.e. at the voltage at which the conductor's surface field is equal to the critical field. This is what we call 1.2...