Transfer Function Based Input Impedance Determination of Triple Active Bridge Converter

Abstract

The concept of multiport dc-dc converter was proposed to reduce the conversion stages of dc microgrid on more electric aircraft (MEA). The structure of multiport dc-dc converter is basically developed from the dual active bridge (DAB) converter because of its galvanic isolation and bidirectional power flow. A power electronics converter as a key element of the electrical power distribution system may cause stability issues. To address these challenges, the impedance characteristic of the multiport converter will be analyzed. In this paper, a transfer function based small signal model is developed and validated with a switching model, to figure out the characteristic of input impedance of triple active bridge (TAB) converter. Preliminary experimental results are presented to be as a support.

A Generalized Input Impedance Model of Multiple Active Bridge Converter

“…By contrast, a transfer function block scheme based on the small signal equations derived from power equation of DAB converter was proposed in [23], which is apparently much easier. Based on that, an input impedance model of TAB converter has been worked out in [24]. In this section, a further generalized model of the input impedance of MAB converter is developed.…”

“…In this section, the TAB converter and the QAB converter are chosen to be validated with the generalized model, while Matlab is used to plot the input impedance of converter and an ideal switching model is built in PLECS to measure and verify the input impedance. A preliminary validation for the input impedance of TAB converter has been already done and shown in [24].…”