| The Impedance-Matching Balance Transformer(IMBT), adapting to the developing requirements of electric railway in our country, is a kind of new traction transformer, which is one of the most important electrical equipments in traction substations. The status of traction transformer directly influences the stability and reliability of the traction power supply system. It is a step-down transformer, transferring symmetrical three-phase voltage in primary side to perpendicular two-phase voltage in secondary side. It is different from any other transformers, it is important for us to design a new effective and valuable protection equipments.According to the electromagnetic relationship of IMBT we analyze the basic nature, the running principle and the data selection of electrified railway impedance-matching balance traction transformer, and describe the equivalent circuit, which can convert three-phase voltage into perpendicular two-phase voltage. This thesis also gives transformation relationships between current and voltage respectively, and a variable range of impedance-matched factorThe things that affect the preciseness of implementation of protection are summarized, especially the inrush current. Then on the basis of the analysis of the inrush current's characteristics, the present protective algorithm of identifying energizing inrush current is improved... |
