An Interleaved High Step-Up Boost-Zeta Converter Using Coupled Inductors With Resonant Soft-Switching

An interleaved high step-up boost-zeta converter with resonant coupled inductors voltage multiplier cell is proposed in this article. The proposed converter achieves very high voltage gain by integrating the boost converter and the zeta converter and using coupled inductor voltage multiplier technique. Meanwhile, low input current ripple and continuous output current are realized, which is beneficial for photovoltaic, fuel cell, and dc-bus. Moreover, the zero-voltage switching (ZVS) and low voltage stress of the switches are achieved by utilizing the active clamp circuits. With the resonance between the leakage inductance and the resonant capacitor in the resonant coupled inductor multiplier cell, the zero-current switching (ZCS) of the diodes are achieved, leading to low reverse recovery losses. In addition, the main switches of the proposed converter can be operated in the full duty cycle range, which achieves a wide range of step-up regulation. The operation principles and steady-state performance of the proposed converter are analyzed in detail. A 400 W prototype with 30-40 V input, 400 V output is built to verify the theoretical analysis.