Analysis on the Adaptability of Asymmetric Singlephase Substitution for 500kV Autotransformer Considering Winding Capacitance

摘要

In order to analyze the validity of the practical case that using the standby transformer of No.1 main transformers to substitute the broken transformer in No.2 main transformers in a 500kV substation, a new model of 500kV power transformer was introduced in PSCAD /EMTDC. Especially the distributed capacitance was considered in the model which is usually ignored for power transformer. And the effect of unbalanced winding impedance and distributed capacitance among the transformers was analyzed based on the model. The results of the transient and steady simulation conformed well to the experimental ones which show that a certain degree of asymmetry is allowed for impedance of windings, but the characteristics of distributed capacitance would affect the balanced operation of the power transformer which should be concerned.