A Small Signal Model of Dual Bridge Series Resonant DC/DC Converter for Power Electronic Traction Transformer

摘要

Dual bridge series resonant converter (DBSRC) is a promising topology applied in power electronic traction transformer (PETT). The dynamic model of DBSRC is rarely reported in current reference, which can give a guidance to design the controller. In this paper, a simple small signal model of DBSRC is obtained through a reduced-order state space equation and then the transfer functions of control-to-output and input-to-output are derived. The simulation at various load under different characteristic impedance and frequency ratio are performed, where the frequency response of DBSRC are measured. The results verify the accuracy of this model at low and medium frequency band, which can reflect the dynamic characteristic of DBSRC and be enough to design the controller.