Low current ripple high step-up interleaved boost converter with switched-capacitors and switched-inductors

A low current ripple high step-up interleaved boost converter with switched-capacitors and switched-inductors that can be used in renewable resources such as photovoltaic energy and fuel cells is studied in this paper. In the proposed converter, the voltage gain is significantly increased and the voltage stresses of the switches are reduced by applying two switched-inductor units to replace individual inductors and by adding a switched-capacitor network to the output side. In addition, the current ripple of the inductor branch is reduced with the help of introducing a coupled-inductor, while the dynamic response speed remains almost unchanged. Therefore, smaller inductors can be used to reduce the volume of the converter. In this paper, the operating principles; the steady-state performance including the voltage gain, the voltage stresses of the switching devices, and the current ripple of the inductor; and transient-state performance of the proposed topology are analyzed. Moreover, the design criteria of the coupled-inductor are given in detail, and the double closed-loop PI controllers are designed. Finally, experimental results are given for a 160 W, 18 V input to 240 V output prototype. These results verify the correctness of the theoretical analysis. In addition, the efficiency analysis and power calculations are also discussed.