A simple approach to improve lightning performance of an uprated substation

This paper presents a simple method to minimize lightning surges entering an uprated or compact substation. A severe lightnmg stress is caused by a backllashover in close proximity to the substation. Feasibility of uprating is based on the surge arrester technology available at present. However, some aspects of line design offer opportunities in reducing Gequency and seven@ of lightrwg surges imposed on the substation. The tower surge response adds an inductive ʹovershootʹ only during the front ofʹ the stroke whch reduces considerably during the tail. If backflashover does not occur before reflections from adjacent towers anive, it is unlikely to occur at all. Use of guys and underbuilt ground wires in the limiting distance will produce reflections with larger maptude and reduce the effective surge impedance of the towes. Th~ws ould not only reduce backflashover frequency but will also r"i:. e crest and duration of surges entering the substation.