Instantaneous Current and Average Power Flow Characterization of a DC-DC-DC Triple Active Bridge Converter

The Triple Active Bridge (TAB) is a three-port power converter that facilitates bi-directional power flow and provides galvanic isolation, making it a subject of significant research attention. This is attributed to its diverse applications in high-frequency DC-DC conversion, electric vehicles, renewable energy integration, and micro-grids. Controlling the system at run-time involves modification of the two phase-shift parameters between respective bridges. By analyzing the fundamental converter operating equations, future control designers can use this framework to optimize control schemes to mitigate the under-determined nature of the TAB converter. In this paper, we elucidate the foundational operational principles of the TAB and establish the defining equations for instantaneous current and average power flow. Furthermore, we validate these equations through a comparative analysis involving a simulation model of the TAB in PLECS and hardware implementation.