Single-Switch High Step-Up Quasi-Z-Source DC-DC Converter with Low Switch Voltage Stress

In this paper, a high step-up converter is presented by integration of switched capacitor and coupled inductors with quasi-z-source structure. a switched capacitor along with a pair of coupled inductors are utilized to enhance voltage gain and switch voltage stress. Also, zero current switching for switch at turn-on and for all diodes at turn- off which reduce reverse recovery problem are achieved by this technique. A passive clamp circuit is utilized to absorbing the leakage inductance energy, and improve voltage gain by placing the clamp capacitor in the charge path of the switched capacitor. Also, the main properties of quasi-z-source converter such as common ground between the output and input sides along with continuous input current is maintained. Additionally, these features are realized by proper component count in comparison with other related topologies based on quasi-z-source topology. The experimental results are extracted by a prototype circuit implemented at 300W and 100kHz to confirm the theoretical results and the proposal converter operation.