Isolated Zeta-SEPIC bidirectional dc-dc converter with active-clamping

This paper proposes an isolated bidirectional dc-dc converter, based on the duality between Zeta and SEPIC converters. Active-clamping is used to recycle the energy trapped in the transformer leakage inductance and to protect the power semiconductors against over-voltages. Theoretical analysis, modulation strategy and experimental results are included in the paper. A laboratory prototype, rated at 1kW, with an input voltage of 100 V, an output voltage of 133 V and 50 kHz of switching frequency validates the predicted theoretical results. The proposed converter is suitable for several practical applications such UPS, electric vehicle, energy storage end smart grids.