On Application Features of Nonlinear Surge Suppressors on Overhead Power Transmission Lines

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Vol. 54, No. 4, November, 2020

ON APPLICATION FEATURES OF NONLINEAR SURGE SUPPRESSORS ON OVERHEAD POWER TRANSMISSION LINES M. Sh. Misrikhanov1 and A. O. Mirzaabdullaev2 Translated from Élektricheskie Stantsii, No. 5, May 2020, pp. 35 – 39.

The problems of lightning protection of overhead power transmission lines (OL) in modern conditions and the application features of nonlinear surge suppressors (NSS) on overhead lines are considered. The results of a critical analysis of the experience of design, construction and operation of transition points of cable and overhead power transmission lines (COL) in Russian power industry are presented. Keywords: lightning protection cable; impulse insulation strength; cable and overhead power transmission line; nonlinear surge suppressor; transition point.

high-speed NSS-OL devices [1 – 5] are being actively implemented. The main motives for using NSS on OL were the emerging problems with the efficiency of the lightning protection cable (LPC). In the areas with ultra-high soil resistivity (rocks with a resistivity of more than 1000 Ohm-m or permafrost), the conditions for the LPC operation become more complicated, i.e., ensuring the normalized resistance of grounding devices (GD) of supports, or more emergencies occur due to gust and glaze loading on LPC than from lightning overvoltages. Assessment of Functional Capabilities of NSS and LPC on OL. To solve the issue of choosing lightning protection means, it is necessary to determine the required level of reliability and lightning protection of OL, taking into account the climatic conditions area (CCA) in terms of ice coatings, wind loading, thunderstorm activity and geophysical characteristics of the soil at the site of installing footings and grounding devices. To analyze the application features of LPC and NSS on OL, the operation principles of these devices need to be considered, taking into account individual nuances and factors that affect the efficiency of each of them. The LPC functions are often underestimated due to the oversimplification of its operation. It is believed that the LPC takes on lightning strikes only due to the fact that it is located above the wires. In fact, this is not at all the case. Being a simple device in design, the LPC is the simplest, cheapest and most reliable protective mean against direct lightning strikes on wires. LPC on 110 – 220 kV OL reduces the number of direct lightning strikes on wires approximately by 100 times [4]. When the lightning leader approaches, the LPC “sucks” opposite charges from the ground through the GD

At the moment, due to the development of the Russian electric power industry, in the country’s power grid, gas-insulated switching equipment and gas-insulated switchgears (GIS), new types of cable products: cables with cross-linked polyethylene insulation (XLPE cables), composite insulators and insulating structures, and nonlinear surge suppressors for overhead lines (NSS-OL) have been widely used. At the same time, the structure of Russian electric power industry has