随着单块光伏电池输出功率越来越高,以反激电路为基础的传统光伏微逆变器难以达到高效率,因此桥式电路为基础的微逆变器越来越受到重视。提出一种电流型降压桥式伪直流环节微逆变器。推导了能量缓冲电感的选择方法,得到了其中各开关器件的电流应力。对所提微逆变器与传统反激式微逆变器在开关管的导通损耗、二极管的导通损耗、伪直流环节滤波效果、开关损耗方面做了详细比较,所提微逆变器综合新能优于传统微逆变器。200 W样机的实验结果证明所提微逆变器性能优良。
With continuous increase of rated power of photovoltaic cells, conventional micro-inverter based on simple flyback topology cannot realize high conversion efficiency. Thus, micro-inverter based on full-bridge topology attracts more and more attention. This paper proposed a current-fed buck-type full-bridge pseudo DC link micro-inverter. Design principle of energy buffer inductor was derived and switch current stress was obtained. Compared with conventional micro-inverter, comprehensive performance of the proposed micro-inverter is remarkably improved. These performance factors comprise conduction loss of switches and diodes, ripple in pseudo DC link voltage, switching loss, etc. Experimental results of 200 W prototype verify validity of theoretical analysis.