DC Power Line Changing of Macroscopic Particles and Associated Electrical Precipitation on Insulators

The objective is a model for estimating the rate of electrical precipitation of macroscopic particles onto insulators where the particle charging is due to ions generated by the line and associated apparatus. The general theoretical structure required to describe particle charging and convective turbulent diffusion in a state-space of position and mobility is developed as a basis for predicting deposition in specific configurations. A wind tunnel facility is described for testing predictions of the theory for charging in the vicinity of a power line. The tunnel is equipped to control the turbulence level, with monodisperse zerocharge particles introduced upstream of a cable which is itself in a controlled state of corona discharge. Equipment for measuring the spatial distribution and mobility distribution at a downstream plane includes an electric analyzer, particle neutralizer, and mass monitor. The theoretical model, which predicts the lower extreme of the observed mobility distribution but a lesser spread than found experimentally, points to either a need for greater resolution in the mobility spectrum analyzer, or the existence of near-line turbulence generation associated with corona wind.