提出一种高增益交错耦合电感直流一直流升压变换器,适用于低输入电压、高输入电流的低压可再生能源发电系统应用场合,如光伏/燃料电池发电系统。该变换器在输入端把两个耦合电感的原边电流进行交错并联,减小了输入电流和输出电压纹波;两个耦合电感的副边串联后再与一电容相结合组成倍压单元,进一步提高变换器的电压增益。该电路结构中,使用两个交错串联的输出电容,它们既能回收利用耦合电感的漏感能量,又能钳位开关管的漏源电压,减小开关管电压应力,因此,有利于选择低导通电阻、高性能的开关器件以进一步减小功率管的开关和导通损耗。另外,耦合电感的漏感可使主开关管零电流开通,同时漏感也能控制二极管关断电流的下降率,大大减轻二极管的反向恢复问题。论文详细分析所提变换器的工作原理和稳态特性,最后通过一台实验样机验证了理论分析的正确性。
A novel high step-up interleaved dc-dc converter topology with two coupled-inductors is presented for low input voltage and high input current applications, such as photovoltaic and fuel cell generation systems. In the proposed converter, the primary currents of two coupled-inductors are interleaved in parallel at input, which reduces the input current ripple. The secondary sides of two coupled-inductors are connected in series with a capacitor for a double voltage cell to improve the voltage gain further. Moreover, this structure can also reduce the voltage/current stresses of active switches and diodes. The leakage energy can also be recycled by the two output capacitors, which are charged interleaving in parallel and discharged in series. In addition, the reverse-recovery problems of diodes are alleviated significantly by the leakage .inductance. The operating principle and the steady-state characteristics are discussed in detail to show the merits of the presented converter and the corresponding model is also derived. Finally, a rating prototype system is constructed to verify the effectiveness of the proposed converter.