Parameter Selection Suggestion of Power Frequency Follow Current Interruption Capability for Multi-chamber Gap Lightning Protection Device Used in 10 kV Distribution Lines

Abstract

In recent years, number of multi-chamber gap lightning protection devices are installed in some 10 kV overhead distribution lines in China. Due to insufficiency of relevant research, selection of key parameters for rated interrupted power frequency follow current of the multi-chamber gap products currently lacks theoretical basis. This paper establishes a short-circuit fault calculation model and, combining experimental data of typical multi-chamber gap products, calculates actual currents through the multi-chamber gap under different fault conditions. Combined with the lightning protection requirements of 10 kV line project, following suggestions are proposed: for the multi-chamber gap products used on urban lines shielded with objects or green trees, the short-term rated interrupted power frequency follow current not less than 1 kA can be selected, and for long-term application, not less than 1. 5 kA should be selected; for the multi-chamber gap products used on the lines in open areas, the short-term rated interrupted follow current not less than 5 kA can be selected, for long term application, higher interrupted follow current level should be selected as far as possible. Suggestion for installation and usage are also provided.