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In this article, a novel dual active clamp converter with high voltage gain is proposed for dc–dc applications. The active clamps’ switches turn on and off under zero-current switching (ZCS). In addition, the main switch turns on under ZCS condition, as well. Therefore, switching losses are significantly reduced. The converter is also capable of operating under quasi-resonance (QR) mode. In this mode, switching losses are reduced further by lowering the voltage and current, at which the main switch turns off . In comparison with the conventional interleaved converter, the voltage gain of the proposed converter is almost the same, but the number of semiconductors and switching loss are significantly reduced. The switching frequency of the active clamps’ switches is half of the main switching frequency. The operation principles of the proposed converter are studied in both pulsewidth modulation and QR modes, and the advantages are investigated. A 200-W prototype is implemented to validate the desired functionality of the converter, and experimental results are compared in both modes.

A new partly isolated three-port converter is introduced in this study for hybrid energy applications. Two boost circuits form the main input port and a bidirectional battery port of the converter. Therefore, both of them are of a current-fed type, making the converter more suitable for renewable energy applications. In addition, the boost circuits are benefited from a mutual active clamp circuit. The circuit in cooperation with the leakage inductance of transformers provides soft switching, while employing a few number of semiconductors. Furthermore, on the secondary side, two voltage-doubler rectifiers are merged. As a result, the converter employs less number of components, which participate in all power conversion modes. Since most of the renewable energy sources have a relatively low voltage level, the converter retains high voltage gain. These features have resulted in an efficient and inexpensive converter. A thorough analysis has been made and justified by simulation and experimental results.

A quasi-resonant dc–dc converter with high voltage gain and low current stresses on switches is proposed in this paper. This converter preserved inherent advantages of current-fed structures, for instance, zero magnetizing dc offset, low input ripple, and low transformer turn ratio. Moreover, by employing the active-clamp circuit, the voltage spikes across the main switch, due to the existence of leakage inductance of the isolating transformer, is absorbed, and switches work in zero voltage switching. Since quasi-resonant switching strategy is employed, turn-off current (TOC) and losses of switches are considerably reduced. Because of zero current switching (ZCS), reverse recovery problem of diodes is alleviated. Experimental results on a 150-W prototype are provided to validate the proposed concept.