Decoupled Power Flow Control and Minimization of Back Flow Power in Triple Active Bridge DC-DC Converter

Abstract

The coupling effect in a Triple Active Bridge (TAB) DC-DC converter is a key issue that affects the output port powers when any of the port power is changed. Therefore, to mitigate the coupling issue, a decoupling control matrix is defined and employed along with the system matrix. The issue of back flow power (BFP) poses another challenge in TAB converter operation, the existence of which reduces the system efficiency substantially. In this work, a detailed analysis of power flows among the TAB ports is done using single phase shift (SPS) and penta phase shift (PPS) modulation schemes for DC Microgrid (DCMG) and battery energy storage systems (BESS) applications. Furthermore, a comparative analysis of BFP minimization is done, and plots of power flow, BFP are presented to illustrate their variations with the variations in phase shifts. A three-port TAB converter system is simulated in MATLAB/Simulink r2021b environment for dc microgrid application with integrated BESS. The simulation results obtained in this study are presented and discussed in detail.