Effect of the Tap Winding Configurations on the Leakage Reactance of the Concentric Transformer Coils

Leakage reactance is one of the major parameters for the designing of the power transformer. Knowledge of the leakage reactance of the distribution transformer provides good information about the condition of the transformer to the designers and electric distributors. Location of the regulating coil in the transformer affects the leakage reactance and operational behavior of the transformer. This paper presents design principles of regulating coil in transformers and shows the effect of the regulating coil on the leakage reactance by using finite element method. Five different types of tap winding configurations are examined in this study. The leakage reactance of the transformer during normal condition is also compared with the analytical methods and experimental test. The results are also compared with the ANSI/IEEEC57.12.00 and IEC 60076-1 international standards.