A Laboratory Study on RI, TVI and an of Insulator Strings Under Contaminated Condition

This paper reports the results of a laboratory study on radio interference ( RI), television interference (TVI) and audible noise (AN) of insulator strings for transmission lines of 154- , 275- and 500-kV classes. When insulators are contaminated and wetted, RI, TVI and AN becompe pronounced. The RIV, TVI and AN from insulator strings that were artificially contaminated with salt and kaolin were measured under artificial fog. Also, investigated were the ratio of TV signal intensity (S) to insulator noise intensity (N), and its degree of interference to TV picture.