Efficient impedance source-based high voltage gain converter with smooth input current

This paper proposes a new soft switched high step-up quasi Z-source converter. The innovative combination of coupled inductors and switched capacitor techniques with the basic quasi-Z-source structure, results in a high voltage gain and low switches voltage stress converter. These features are achieved at a low coupled inductors turns ratio while maintaining the continuity of the input current and common ground between the input and output. This converter provides soft switching at zero voltage for all switches and eliminates capacitive turn-on losses. Furthermore, the proposed structure has solved the high conduction loss of the input side diode in the basic quasi-Z-source structure which is key challenge. This converter eliminates the reverse recovery problem for all diodes, and no limitation is imposed on the duty cycle relative to the basic structure. Moreover, the leakage inductance energy is absorbed and recycled into the load. The proposed converter contribution is simultaneous possession of all the above-stated advantages which are absent among the competitors. The introduced converter is thoroughly analyzed and the converter characteristics are validated over other counterparts by the implementation of a 200W laboratory prototype.