Zero Sequence Impedance of Yg-Yg Three Phase Core Type Transformer

Abstract

-In this paper, zero sequence equivalent circuit of Yg-Yg three phase core-type transformer is analyzed. Many problems by iron core structure of the three phase transformer due to asymmetric three phase lines, which includes line disconnection, ground fault, COS OFF, and unbalanced load are reported in the distribution system. To verify a feasibility of zero sequence impedance of Yg-Yg type three phase transformer, fault current generation in the three phase core and shell-type Yg-Yg transformer is compared by PSCAD/EMTDC when single line ground fault is occurred. As a result, shell-type transformer does not affect the flow of fault current, but core-type transformer generate an adverse effect by the zero sequence impedance. The adverse effect is explained by the zero sequence equivalent circuit of core-type transformer and Yg-Yg type three phase core-type transformer supplies a zero sequence fault current to the distribution system.

Informe de respuesta rápida sobre la efectividad de las medidas no farmacológicas que afectan a la actividad de la restauración interior, restauración exterior y ocio nocturno en el contexto de la pandemia por COVID-19

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Regenerative Engineering of the Rotator Cuff of the Shoulder

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Stand-Alone Microgrid Inverter Controller Design for Nonlinear, Unbalanced Load with Output Transformer

“…As a result, the load-side zero sequence component is controlled by the transformer. Problems occur, such as an increased transformer temperature and an increased loss [14]. On the primary side, which has capacitors that determine the output voltage, the zero sequence component is not transmitted, so a zero-sequence-component voltage does not occur on the primary side.…”

“…Three-phase, four-wire inverters for removing the zero sequence component and negative sequence component have been studied [9][10][11][12][13], but these studies do not address the zero sequence component impedance caused by the transformer structure. There have also been studies on the zero sequence component impedance caused by the transformer structure in electric power distribution systems [14][15][16], but there have been no previous studies on stand-alone inverters.…”