Fast front transients in transformer connected to gas insulated substations: (white+black) box models and TDSF monitoring

Abstract

Protection to fast front transients of power transformers connected to Gas Insulated Substations (GISs) requires not only detailed model of the GIS but also of the power system components connected to it including the power transformers themselves. Transformer models with different degree of modeling detail have been proposed in the literature. However, there is no single model able to represent at the same time the transient performance both outside and inside transformer when connected to the power system. This paper reports an investigation that shows the valuable information obtained when a white+black box representation is used to model the transformer in fast front transient simulations. Precisely, transient overvoltages will be simulated and the time domain severity factor (TDSF) will be monitored in an actual GIS model in the ATP/EMTP program.