Residual dc charge decay mechanism in a transmission line under fine and dry weather conditions

Authors once measured time constants of residual dc charge decay in a 500 kV transmission line during five fine and dry days of winter season. The results showed a large scattering without depending on the simultaneously measured weather conditions, such as temperature or humidity. Then the authors have performed an additional experiment in a laboratory to discuss the factors that affect the residual dc charge decay in a dry condition. And it is shown that dusts blown up and transported by wind play an important role for the charge decay.