Current-fed three-phase soft-switching DC/DC converter with natural device commutation and voltage clamping

A novel bidirectional snubberless naturally commutated soft-switching current-fed three-phase DC/DC converter is proposed. This proposed secondary modulation technique naturally clamps the voltage across the primary side devices with zero current commutation (ZCC) eliminating the necessity for active-clamp circuit or passive snubbers. Switching losses are reduced significantly owing to zero-current switching (ZCS) of primary side devices and zero-voltage switching (ZVS) of secondary side devices. Soft-switching and natural voltage-clamping (NVC) is inherent and load independent. The proposed bidirectional converter shows better performance i.e. high efficiency, high density, high reliability, small volume, light weight and low cost. These merits make the converter promising for electric/fuel cell vehicles, front-end dc/dc power conversion for solar/fuel cell inverters and energy storage. Steady state analysis, design, and experimental results are presented.