Zero-voltage-switching dual-boost converter with multi-functional inductors and improved symmetrical rectifier for distributed generation systems

In this study, an advanced interleaved active clamp dual-boost converter is proposed for distributed generation systems with large input current, high-output-voltage and high-step-up conversion. There are only two coupled inductors in the proposed converter and both of them can be integrated into one magnetic core to improve the power density. The multi-functional integrated inductors can serve as inductors for current ripple cancellation and transformer for primary-secondary isolation. Furthermore, an improved voltage-doubler configuration is derived on the secondary side to make the output diodes sustain only half of the high output voltage. The output diode voltage stress can be auto-balanced because of the secondary series-connected structure of the multi-functional integrated inductors. In addition, zero-voltage-switching operation is achieved for all the primary switches during the switching transition. The output diode reverse-recovery problem is alleviated because of the leakage inductance. Finally, a 1-kW 40-380-V prototype is built to demonstrate the effectiveness of the theoretical analysis.