Online Optimization of the Triple-Active-Bridge Converter Control Parameters for Maximum Efficiency Point Tracking

This article presents the formulation, implementation, and execution of the switching network loss optimal hybrid phase-duty control strategy for a triple-active-bridge (TAB) converter. The work aims at providing an efficient and easy-to-implement solution for incorporating the dynamically varying optimal bridge voltage duty cycle parameters based on the operating load and output voltage gain condition that ensures the maximum efficiency operation of the TAB switching network. With this purpose, a detailed mathematical framework is formulated and presented in the paper that synthesizes the polynomial regression models for the optimal duty variables as a nonlinear function of the operating load and gain condition. These developed models are implemented inside the controller along with the decoupled PI controllers that control the phase-shifts. With the implementation of the proposed optimal hybrid phase-duty control, the experimental result shows an efficiency increment up to 2.9% compared to the conventional phase shift modulation alone.