Density dependence on negative corona onset voltage in helium

A New Method for Calculation of Corona Inception Voltage in Stranded Conductors of Overhead Transmission Lines

“…Broche and et al [8] discussed the variation of negative corona onset as a function of helium density. In this work a new method for calculation of corona voltage inception is presented.…”

“…Assume N1 (r = r1 = b) is the free electrons at the surface of conductor. The number of free electrons at the position r = r2 can be found by (8).…”

“…In the ionization zone, the value of a is greater than i7. So according to (8), numbers of free electrons are increased until r = (T. Maximum value of free electrons exists at the boundary of ionization zone (a = C). Numbers of free electrons at this boundary can be used as a criterion to calculate corona inception voltage.…”