Lightning Protection using LFA-M

Outages of overhead power lines due to lightning strokes are one of the main causes of shortages of electric supplies and economic losses of power utilities. A previous study has concluded that widely separated pole-top arresters can effectively protect distribution line from induced-voltage flashovers. In order to prevent arc fusion of insulated conductors on distribution lines due to lightning flashovers it is recommended to install an arrester at every insulator. Millions of metal - oxide arresters are already installed in Japan and more will be installed in the future. The main problem of using pole-top arresters is their high cost. For mass application of arresters for 1ightning protection of overhead distribution lines, an arrester must be cheap, reliable with no need for maintenance. The method suggested in this paper for the protection of distribution lines is a simplified discharge circuit. It consists of a long surface flashover discharge element, called Long Flashover Arrester (LFA), with a length greater than that of the insulator which it protects. The LFA can be connected between the conductor and ground or in series with the insulator. It is inexpensive (its construction is simple) and reliable because lightning discharge develops along the LFA and no Power Arc Follow (PAF) occurs.