Analysis of the Transformer Influence on a Three-Phase Dual Active Bridge DC-DC Converter

In this work, the impact of the high-frequency transformer on the three-phase dual active bridge DC-to-DC converter operation is investigated, using four transformers with different connections: star-star, delta-delta, star-delta and delta-star. The main objective is to evaluate what is the transformer connection that allows the converter to be operated with high efficiency for different voltage conversion ratios and output power. The apparent power requirements of the high frequency transformers and the power semiconductors stress are evaluated, which allows obtaining the soft switching operating range for each transformer connection. The results of the analysis allow to select the most suitable transformer connection for each application.