Unified Time and Frequency Domain Power Flow Analysis of Triple Active Bridge DC-DC Converter

Abstract

The triple active bridge converter (TABC) is a threeport isolated dc-dc converter topology capable of bi-directional power transfer between the ports, making it highly suitable for energy harvesting and storage systems. This work presents a time domain analysis (TDA) and General Harmonic Analysis (GHA) of power flow of a TABC in single phase shift (SPS) and penta phase shift (PPS) modulation techniques. The converter’s circuit configuration, operating principles, and mathematical modelling are discussed to explain the influence of phase shifts on power exchange among the ports. SPS is examined for its simplicity and suitability in port power control, while the PPS is analysed for its enhanced flexibility in independent multi-port power and circulating power regulations. Mathematic analysis and derivations are presented along with simulation results to validate the theoretical models and highlights the accuracy differences between TDA and GHA. These findings provide guidance for the appropriate selection of power flow analysis method to enable effective design of the TABC for various applications.