Electric strength of arrester for lighting shielding of 6-35 KV transmmcsion line with lightning overvoltage

Abstract

The most common device for protection against overvoltages is a valve-type arrester. Due to obsolescence it is proposed to replace valve-type arresters with nonlinear overvoltage limiters or multi-chamber arresters. Modern recommendations for the selection of means for protection against overvoltage take into account not all factors when placing protection devices. For example, when replacing valve arrester with non-linear overvoltage arresters (ar-rester), accidents often occur. Often, due to the replacement of protective devices, there are violations of the operating conditions of new devices, since in the design of the arresters, they are placed in place of the vale-type arresters. Nonlinear surge arresters have a number of reliability problems, for example, due to frequent single-phase ground faults, thermal instability problems occur. Therefore, as an alternative to arresters in urban distribution networks, it is proposed to use multi-chamber arresters – devices that are a series of discharge chambers in silicone rubber. The purpose of this work is to calculate the electric field strength and conductivity at the exit from the discharge chamber of the multichambe arrestor, study the effect of multichamber dischargers on distribution networks, build up the dependence on the voltage and conductivity of the plasma exhaust gases, depending on the distance to the multichambe arrester.