An Impedance-Source-Based Soft-Switched High Step-Up DC–DC Converter With an Active Clamp

This article proposes a high step-up dc–dc converter based on a trans-inverse impedance-source structure, in which the voltage gain of the converter is increased by using a lower number of turns ratio of the coupled inductors (CI) windings. The proposed converter achieves a very high voltage gain and a very low voltage stress on the switches. An active clamp is incorporated into the topology of the proposed converter, helping to absorb the energy of the leakage inductances of the CI, and to recycle that energy to the output of the converter to further increase the voltage gain. Furthermore, the active clamp is used to realize soft turn
on
for the main switch of the converter. Additionally, the clamp switch also turns
on
under zero voltage switching condition. Apart from the soft turn
on
of the switches of the proposed converter, the diodes of the converter also turn
off
with a minimized reverse recovery power loss because of the controlled current falling rate of these diodes with the leakage inductance of the CI. The operation principle, steady-state analysis, and comparison are presented in this article. Also, the analysis is verified using a 200 W, and 20 V to 400 V experimental setup.