A new simple, effective and inexpensive method for lightning protection of medium voltage overhead distribution line is using long flashover arresters (LFA). A new long flashover arrester model has been developed.
It is designated as LFA-M. It offers great number of technical and economical advantages. The important feature of this modular long flashover arrester (LFA-M) is that it can be applied for lightning protection of overhead distribution line against both induced overvoltages and direct lightning strokes.
The induced over voltages can be counteracted by installing a single arrester on an overhead line support (pole). For the protection of lines against direct lightning strokes, the arresters are connected between the poles and all of the phase conductors in parallel with the insulators.
A long flashover arrester (LFA), which comprises of three flashover modules using the creeping discharge effect, is described in this paper. In this design, the total arrester stressing voltage is applied simultaneously to all of the three modules so that the voltage-time characteristics of the arresters are improved.
It assured reliable protection of medium voltage (e.g., 10kv) over head power line against both induced over voltages and direct lightning strokes.
A single LFA per support or pole is found to be sufficient to protect an over head line against induced over voltages. An LFA should be arranged in parallel with each insulator in order to protect a line against direct lightning strokes...
praveen.....
excellent
