Non-circulating-current phase-shift control method for dual active bridge converter

Abstract

The present invention relates to a non-circulating-current phase-shift control method and system for a dual-active-bridge (DAB) converter. This method addresses the issue of circulating power arising from voltage mismatch between the primary and secondary sides of the DAB converter, which otherwise results in increased current stress, higher power losses, and elevated system costs. To eliminate circulating current, the proposed control strategy constrains the ratio between 1-D1 and 1-D3, denoted as a, based on the primary-side and secondary-side voltages as well as the transformer turns ratio. A normalized transmitted power Y is then calculated, and the optimal set of phase-shift ratios D1, D2 and D3 is selected to minimize both switching and conduction losses under non-circulating-current power transfer, thereby enabling high-efficiency operation. The method further ensures zero-voltage turn-on for all switches and zero-current turn-off for half of the switches, significantly reducing switching losses.

Dependencies are inferred from the claim text.