Insulation Requirements, Corona Losses, and Corona Radio Interference for High-Voltage D-C Lines

Explaining the impact of conductor surface type on wet weather HVDC corona characteristics

“…Outdoor measurements were able to confirm a significant increase of ion current and electric field levels [7,8,9,6,10,2] as well as a considerable influence on radio interference (RI) [11,12] due to rain. However, the published 20 data is limited and contains no detailed information that would allow to correlate rain drop properties and electrical corona characteristics.…”

“…[13,14,15,16,17]) and those that took a very macroscopic view, analyzing outdoor field test data on full-scale 80 lines (e.g. [12,11,6,2]). …”

Corona Current Coupling in Bipolar HVDC and Hybrid HVAC/HVDC Overhead Lines

“…This publication therefore focuses on experimental sources that specifically report conductor ion currents. Notable publications that contain such data include [16]- [21].…”

“…Other studies have focused on field strengths in a more practical range and have presented CL data for various weather conditions [16], [17], [20]. Rain is the most appropriate case for comparison as it shows the lowest seasonal variations and at the same time produces the highest CL [20].…”

“…Fig. 5 shows measured and computed foul weather CL values for three different test lines [16], [17], [20]. In each of these publications, average CL values for rain were explicitly or implicitly presented.…”