摘要
为提高变换效率,无变压器式光伏并网逆变器是近年来的研究热点。针对无变压器拓扑的漏电流问题,提出一种三电平双Buck光伏并网逆变器,是在独立型双Buck三电平逆变器基础上,简化其电路结构得到。对地寄生电容电压被输入电容钳位在母线电压的一半,消除了漏电流。该拓扑续流回路经过的器件较传统拓扑数量少,且不经过性能较差的体二极管,有利于获得更高效率。还提出和分析包括均压控制在内的多环控制策略。仿真和实验验证了该结构及控制方案的正确性和可行性。
To enhance conversion efficiency,the study of photovoltaic grid-connected inverter without transformers is an important trend.In order to avoid leakage currents of grid-connected inverters without transformer,a novel three-level dual Buck grid-connected inverter was proposed,which obtained by simplifying the structure of three-level dual Buck inverters.The voltage of the stray capacitor to ground,which was clamped by the huge input capacitors,was equal to the half value of the bus voltage,so the leakage current was eliminated.The current of this topology pass through fewer elements than that of traditional topology and would not pass through body diodes,so that it could achieve higher efficiency.Meanwhile,a multi-loop control method including voltage-balancing control was proposed and analyzed.Both simulation and experimental results verify that the structure and the control method of this grid-connected inverter is correct and feasible.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2012年第12期7-13,共7页
Proceedings of the CSEE
基金
国家自然科学基金(50907033)~~
关键词
光伏
并网逆变器
无变压器
漏电流
photovoltaic
grid inverter
transformerless
leakage current
