Improved high-gain coupled inductor Boost-Sepic converter

Aiming at the problem of low output voltage level and poor stability of photovoltaic, a high-gain coupled inductor combination Boost-Sepic converter was presented by improving the Boost-Sepic converter and adding two gain units of coupling inductor and switched capacitor. First, the input inductor in the combined Boost-Sepic converter was replaced with a coupled inductor primary side to ensure continuous input side current and clamp the power switch voltage; meanwhile, the coupled inductor multiplier unit was connected in series with the switching capacitor to improve the voltage gain. In the converter, a passive clamp absorption loop was used to recycle the energy of the leakage inductance of the coupled inductor, suppresses voltage spikes generated on the power switch. The new Boost-Sepic converter was analyzed in detail, including the selection of operating modes, voltage gain, switching device voltage and current stress, and device parameters, and compared with other high-gain converters. Finally, the feasibility and correctness of the converter was verified by a 200 W experimental prototype. © 2024 Editorial Department of Electric Machines and Control. All rights reserved.