Corona Modelling for the Calculation of Transients on Transmission Lines

Modelling of the corona characteristics under damped oscillation impulses

“…The ionisation does not develop beyond a fictitious cylinder of radius R 0 , as shown in Fig. 1, R 0 should be large enough to contain the ionised zone [6].…”

“…The narrow helix appearance under negative polarity is more remarkable than that under positive polarity. The formation of the narrow helixes might be ascribed to the occurrence of the opposite polarity corona [6, 7, 25]. In fact, since the applied voltage u is damped oscillatory, the electric field near the inner conductor could be reversed with u approaching to the wave trough.…”

“…In the lightning overvoltage analysis, the charge–voltage curves ( q – u curves) are usually employed to take account of the corona effect. Measurement investigation [1–5] and model computation [6–11] were made for the q – u curves. So far the distortion and attenuation of lightning overvoltage surges are always calculated on the basis of the q – u curves under double exponential impulses, no matter what the surge waveforms are.…”

“…The corona models reported in the literature mainly focused on double exponential impulses. Semlyca and Wei‐Gang [6] assumed the corona geometry to be cylindrical and the electric field intensity in the ionised region will not exceed to a critical value given by a simple algebraic formula. Cooray [7] considered the space charge zone generated by corona discharge to be in a uniformly distributed corona sheath surrounding the corona conductor.…”

Extra high voltage transmission line operation simulation using the actual corona-loss characteristics

“…The physical phenomenon of a corona is very complex. A corona is too complicated to be exactly described by mathematical equations [4][5][6][7][8].…”