A Laboratory Study on RI, TVI and an of Insulator Strings for DC Transmission line Under Contaminated Condition

This paper reports the results of a laboratory study on radio interference (RI), television interference (TVI) and audible noise (AN) of contaminated insulator strings for DC transmission line. It is clarified that RIV (Radio Influence Voltage), TVI and AN levels of contaminated insulator under DC voltage condition are almost the same as those under AC voltage condition, although those of clean insulator and conductor are lower under DC voltage condition than those under AC voltage condition. So, in the DC transmission line, the noises from insulator, especially under contaminated condition, are considered more influential than those in the AC transmission line.