High step-up DC-DC converter with three capacitors clamped circuits for reduced out capacitor stress

In this study, a novel converter which integrates three capacitor clamped circuits and coupled inductor is proposed for high voltage gain. Compared with classical clamped circuit, these clamped circuits which are composed of one diode and three capacitors are used to improve voltage gain and achieve a continuous input current in this proposed converter. The proposed converter has four different clamped circuits, which can be divided into two types, including horizontal clamped and vertical ways. Moreover, each type of new clamped circuit corresponds to two different clamped circuits. This makes the designer have more selections to recycle the energy stored in leakage inductor. Besides, one of the three capacitors is connected in series with the output capacitor to efficiently reduce the voltage stress across the output capacitor, and voltages of both of them are less than half output voltage. Finally, in these converters, a converter based on three capacitor clamped circuit as a representative is analysed in detail. A prototype circuit is established in the laboratory to demonstrate the performances of this converter.