AN EXPERIMENTAL-STUDY OF LARGE ION DENSITY UNDER THE SHIOBARA HVDC TEST LINE

This report describes the characteristics of large ions under the Shiobara HVDC test line found in the experiments concerning the voltage characteristics and lateral profiles. Applied voltage has a less influence on large ion density than on small ion density. The large ion density increases gradually downwind, reaches the maximum value at 67m from the line center and then decreased gradually. But it is 2-3 times larger than its background level (BGL) even at a point 200m far from the line. The empirical equations representing the characteristics of large ion density attenuation are developed. Maximum large ion density becomes nearly equal to 4 x BGL and accounts for about 40% of the density of aerosol less than 1 μm diameter. Keywords: HVDC Transmission Line, Ion, Aerosol, Large Ion Density, Small Ion Density. © 1990 IEEE