Fast practical short-circuit current calculation method based on sequence component in V/v structure traction transformer for electrified railway

Abstract

V/v structure transformer has been widely used in the electric railway traction system. However, the construction V/v transformer compared to three-phase system has a serious asymmetry. It brings new difficulty to the existing setting calculation of power system which is based on symmetrical sequence components. In the paper, by analyzing in-depth the connection mode and equivalent model of V/v structure transformer, a new practical fault calculation method based on sequence component was proposed, and interconnection of sequence networks and formulas for a variety of fault types were given. Compared with the fault calculation method based on phase component model, an example was given to prove its practicability and validity. Combined it with the existing transmission network fault calculation procedures, based on slight adjustments complex fault calculation module of the existing fault calculation procedure, the fault of V/v structure traction transformer can be rapidly calculated and a widely and practical calculation method can be developed.