Protection against Lightning Impulse Ingression to 500 kV GIS and Impulse Analysis
Lixing Zhou · Insulators and Surge Arresters · 2008
Aimed at the overvoltage trouble at substation equipments caused by lightning strikes to overhead line,four protection solutions were proposed.Through ATP simulation,the protection margins and economy of the protective device at transformer,reactor,CVT and GIS-inlet were estimated.It is concluded that installation of a set of outdoor type surge arrester at line inlet and a set of indoor type one at main transformer may effectively reduce the ingressing lightning overvoltage based on fractal theory,the fractal dimension and Kolmogorov entropy of transformer voltage wave were calculated and compared,and a positive correlation between them was proved.It is a proposed that protection solution may be determined using fractal wave characteristics,it is satisfactory when P≥Pi.