Transformer Phase Coordinate Models Extended for Grounding System Analysis

Abstract

The transformer model in phase coordinates should be extended to enable a proper analysis of the associated grounding system currents and potentials. A separate ground connection node is introduced through which the transformer interacts with the substation grounding system. The model proposed yields the transformer terminal phase variables in their natural form, reflecting the voltage ratios and phase shifts introduced by transformer winding connections. © 2002, IEEE. All rights reserved.