A corona discharge is an electrical discharge brought on by the ionization of a fluid such as air surrounding a conductor that is electrically charged. Spontaneous corona discharges occur naturally in high-voltage systems unless care is taken to limit the electric field strength.

This app can predict best height to pole spacing ratio for minimal HVDC Corona Loss. It can also predict the radius at which AC Corona loss will be maximum so as to avoid that particular range.

This app can calculate Corona Power Loss given:-
Radius
Distance between conductors
Temperature
Pressure
Frequency
Operating Voltage

HVDC Corona Loss is calculated from:-
Pole Spacing
Mean Pole Height
Maximum surface gradient (voltage)

Hope you will find it useful.

~Cheers Harsh