Self-Current Sharing in Dual-Transformer-Based Triple-Port Active Bridge DC-DC Converter with Reduced Device Count

A self-current balancing structure of the dual-transformer-based triple-port active bridge (DT-TAB) converter with the reduced component count is proposed in this article for future sustainable energy system applications. The proposed topology inherits good characteristics of the conventional triple-port active bridge (TAB) with even power sharing in an open loop as a newly added function. It can achieve high power density over the existing TAB converters that possess current-balancing function because the need for an auxiliary magnetic circuit or sophisticated control scheme in equalizing the shared power is eliminated. Besides, the demagnetization and magnetic short-circuit problems associated with the conventional TAB converters that are been eradicated, decoupled power flow management is achieved at all conditions. Moreover, the phase shift between the input H bridges gives an additional control degree of freedom that permits the control of the output power or offers independent control of voltage magnitude during the reverse power flow, thereby extending the system-operating range. The proposed DT-TAB converter has been adapted for the two-port operation. All the power switches achieved zero-voltage-switching turn-on. Finally, the robust operation performances of the proposed DT-TAB converter have been verified by the laboratory prototype assembled and tested up to 1 kW. The experimental results presented at the end are the proof-of-concept.