A Wide-Band Modeling Research of Voltage Transformer in EMU

Considering that current voltage transformer models of electrical multiple units (EMUs) are narrow-band or models, this paper introduces a wide-band model EMU transformers based on the vector fitting method, circuit synthesis theory and black-box theory. The admittances from 30 kHz to 5 MHz measured by network analyzer, branch in pi-type equivalent calculated according equation two-port circuit. Based matching rational function formulas obtained, converted into is constructed simulation software, so range kHz–5 MHz. frequency sweeping method used measure transmission characteristics direct (DC)to kHz. modified characteristics, whereby DC-5 obtained. Fast pulse experiments carried out transformer, actual injected fast as excitation source model. measurement results secondary side show has high accuracy.