A simple approach to improve lightning performance of an uprated substation

Abstract

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 'overshoot' only during the front of' 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~s would not only reduce backflashover frequency but will also r " i : . e crest and duration of surges entering the substation.

The simulation and analysis of lighting invasion wave performance for 35 kV substation

“…It will not only damage the insulation of equipment, but also threaten safe operation of the power network [l]. Recent years, the scholars home and aboard present a great of simulation and research on the lightning invasion wave performance o f 1 lOkV and above voltage class substation [2][3] [4]. However, there are still a few researches aiming at Iightning invasion wave of 35kV and lower class substation.…”

Avaliação do desempenho de linhas de 230 kV com underbuilt shield wire frente a descargas atmosféricas

“…foram efetuados em diversos países, como sintetizado nos parágrafos seguintes. Ressalta-se aqui que diversas figuras desta revisão se referem ao underbuilt shield wire como um cabo guarda adicional.Em trabalho produzido na George Washington University por Harrington e Mueen em 1996(HARRINGTON, MUEEN, 1996), foi avaliado o uso do underbuilt shield wire em conjunto com estais (guy wires) como método para minimizar as sobretensões de descargas atmosféricas que chegam até as subestações. Os autores concentraram-se nestas duas técnicas pois a utilização de estais diminui a impedância da torre, enquanto os underbuilt shield wires aumentam o acoplamento entre os condutores, reduzindo a probabilidade de ocorrência de dois condutores alocados entre as alturas de 25 m e 15 m, como exibe aFig.…”