Improvement of Overhead Transmission Lines Lightning Protection by Line Arresters with Separate Groundings and Shielding Wires Fixed at Insulation Racks

This paper sets out a proposal aimed at increasing efficiency of overhead lines lightning protection by using lightning arresters only on one phase (e.g. A) and stand-alone grounding. If it is not metal-connected to the pole it is connected to the pole via earth. Due to the current flow in the earth around the grounding there is distribution of potential, which decreases with offset from the grounding. Conducting pole located at a distance from the grounding gets a potential. Thus, voltage applied to phase B insulator decreases and the probability of its flashover is reduced. However, there is a possibility of phase A insulator flashover. By application grounding at optimal distance from the pole lightning protection level can be twice greater than at traditional pole grounding with the same value of grounding resistance. Efficiency of application of insulating racks for fixing shielding wires connected to standing alone groundings is also shown. Use of standing alone groundings for connection of lightning arresters on the power lines, as well as use of insulation racks for shielding wire with grounding, located at an optimal distance from the poles, appear to be effective technical solutions deserving further elaboration with participation of scientific, design and operational organizations.