Dual active bridge buck-boost converter

A novel isolated bidirectional DC/DC converter suitable for high power applications is proposed. The proposed converter has bidirectional power flow capability with low device ratings for a wide source voltage range. The converter is controlled by varying the duty cycle and phase of the firing pulses, to achieve power flows in both directions and controlled current stresses, resulting in low total device rating (TDR) for a wide source voltage range. The proposed converter can scale to high power and uses system parasitics effectively. As a proof of concept, simulation results and comparison of TDR with conventional solutions based on analytical derivations are presented in a 100 kW level. Design considerations in building DAB³ converter in a 100 kW level are presented.