A new multi-winding traction transformer equivalent circuit for short-circuit performance analysis

Abstract

SUMMARY Current and force calculations in different short-circuit conditions are required for short-circuit performance analysis of a multi-winding traction transformer which is one of the most important requirements in its design process. This paper extends the available low-frequency three-winding star equivalent circuits to develop a novel equivalent circuit for the four-winding traction transformers. The leakage inductances of the traction transformer are determined and employed to calculate the parameters of this developed star model. It is shown that the star equivalent circuit is a valid and appropriate model to simulate the steady-state and dynamic performance of the traction transformer under different short-circuit conditions. To analyze the short-circuit performance of the transformer, the short-circuit currents (simulated by the introduced model) are employed to compute the electromagnetic forces for a typical dry-type traction transformer. The analytical and numerical methods are used for short-circuit force calculations, and those results are compared against each other. Copyright © 2012 John Wiley & Sons, Ltd.