Study on the application to traction power supply system of YNvd transformer

The YNvd transformer, which is one kind of three-phase three-winding balance transformer and has several properties, can be used in traction power supply system of electric railway. The strict relation of the primary and secondary in the electric transformation is derived with the impedance matching coefficient. The grounding conditions for YNvd transformer's neutral point and the characteristics of negative phase-sequence are analyzed. The three-phase equivalent models of traction power supply system with comprehensive compensator and filter are presented unified with power system in related analyses. Finally, the calculation equations of the three-phase and two-phase equivalent bus voltage loss are obtained. All these contribute to the future application of YNvd transformer.