Analysis of Magnetizing Inrush Current of Yy10 Transformer Based on RTDS

Misoperation of the transformer protection device caused by the closing inrush current is one of the important problems that affect the safe operation of the transformer. The research on the mechanism of inrush current, the identification method of inrush current and the research of transformer no-load inrush current have been made some achievements. However, the studies mainly focus on the inrush current of Yd transformer , and rarely discuss the inrush current of Yy10 transformer with no-load closing and line fault coincidence. But the transformer of Yy10 structure transformer is widely used in Shanghai area. Based on the principle of single phase transformer closing magnetizing inrush current, considering the typical Yy10 structure of 110kV voltage level transformer in some area, the operation equation of Yy10 double winding transformer based on this principle is deduced, and the dynamic transformer model based on RTDS is established. The simulation results provide reference for relay protection and engineering application.