Small signal modeling of naturally clamped soft-switching current-fed dual active bridge dc/dc converter and control design using Cypress PSoC

A detailed small signal analysis and a closed loop control design of naturally commutated current-fed dual active bridge (CFDAB) dc/dc converter are presented. Proposed converter is suitable for fuel cell vehicle between traction inverter and batteries. State-space averaging technique is used to derive the small signal model. A closed two-loop controller is designed and implemented on mixed signal processor Cypress PSoC 5. A complete design procedure is presented. Experimental waveforms from a 250W prototype with the designed controller are illustrated to verify the stability of the control system. Experimental results for step changes in load clearly show satisfactory transient performance of the converter and validate closed design. It is suitable for energy storage, interfacing two dc buses of different voltages in DC microgrid, and solar power system to boost low voltage up to peak of the utility voltage.