Investigation of Asymmetrical Modes of Three-Phase Three Leg Combined Transformer-Phase-Shifter

Abstract

On the base of previously proposed model of three-phase three leg transformer windings connection scheme for combined transformer-phase shifter was made, for which calculations and analysis of specific characteristics of different steady state asymmetric modes were performed. At this the electromagnetic coupling of the windings, located on different legs of transformer core was taken into account. As the base 10 kV transformer was used, and different short circuits, combined with phase failures at feeding source were investigated. For the considered regimes vectorial diagrams for windings currents, voltages and relative values of magnetic fluxes in the legs and zero sequence magnetic flux, flows out of magnetic circuit, were constructed, giving clear idea about their particular features.

Keywords

• asymmetric modes
• three legs magnetic circuit