一种带耦合电感和充电泵的单级式高增益光伏微逆变器拓扑

Single Stage High Gain Micro-Inverter with Tapped Inductor and Charge Pump

传统的双级式微逆变器通常由一级具有最大功率点跟踪功能的高增益DC-DC变换器和一级全桥逆变器串级组成。单级式微逆变器可以在一级功率拓扑中实现上述功能,因而具有结构简单、器件少的优势。然而,单级式拓扑在高增益升压、功率解耦方面给设计工作带来了挑战。提出一种带耦合电感和充电泵的单级式高增益微逆变器拓扑,引入耦合电感和充电泵实现高电压增益;利用Boost变换器与全桥逆变器共用开关管实现单级式拓扑;同时保留了高压直流母线,从而可以减小解耦电容容值。仿真和实验结果验证了该拓扑具有较高的电压增益、较小的解耦电容、高质量的正弦输出、以及较高的变换效率。

Traditional two-stage micro-inverter is usually comprised of a high gain step-up DC-DC converter under maximum power point tracking control and a cascaded full bridge inverter. Single stage micro-inverter can achieve the functions above in one power stage, thus it has the advantages of simpler circuit and less components. Neverthe- less, single stage topology has some challenges on high gain voltage step-up and power decoupling. This paper pro- posed a single stage high gain micro-inverter topology with tapped inductor and charge pump. Tapped inductor and charge pump are employed to attain high gain voltage step-up. A single power stage is realized by Boost converter sharing the switches with full bridge inverter. And the high voltage DC bus results in less power decoupling capaci- tance. The simulated and experimental results have proved that the topology has the merits of high gain output and good conversion efficiency.