Impedance Modeling and Stability-Oriented Parameter Optimization of Isolated Dual Active Bridge-Based Two-Stage AC-DC-DC Converter

The isolated dual active bridge (DAB)-based two-stage AC-DC-DC converters have been widely applied in grid-connected power electronics systems. However, the impedance interactions between DAB converter and AC-DC rectifier can cause instability problems to accurate terminal characteristics of are still not clear due high frequency ac conversion stage. This makes it difficult assess impacts circuit parameters on stability converters. To address these issues, models originally derived this paper. Based developed models, DAB-based is analyzed. comprehensively revealed by Bode Nyquist plots. analysis results offer instructive implications finetune design rules conclusions validated comprehensive simulation experimental results.