无漏电流高效可靠三电平双Buck并网逆变器  

High-efficiency High-reliability Dual Buck Three-level Grid-connected Inverters Without Leakage Currents

作　　者：洪峰[1] 刘周成[1] 万运强[1] 尹培培[1] 赵鑫[1] 王成华[1] 

机构地区：[1]南京航空航天大学电子信息工程学院,江苏省南京市210016

出　　处：《中国电机工程学报》2014年第9期1327-1336,共10页Proceedings of the CSEE

基　　金：国家自然科学基金(50907033);江苏省科技支撑计划(BE2012170)~~

摘　　要：漏电流降低了非隔离型并网逆变装置的安全性和可靠性。已有研究通过将双极性调制全桥逆变器或半桥逆变器三电平化解决该问题。提出基于三电平双Buck逆变器的新思路,并重点研究其中的三电平双Buck全桥电路。该拓扑是将双Buck半桥逆变器中的输入均压电容用一个工频开关的桥臂取代得到,使得对地寄生电容电压在半周期内保持不变,有效地抑制漏电流至几乎可以忽略的程度。同时,该拓扑保持了双Buck电路无桥臂直通、体二极管不工作等特点,又降低了器件电压应力,使得桥臂输出变为单极性调制波。通过与各种无漏电流结构的综合比较可知,该拓扑除在器件总量上比H5结构多一个功率管外,在有源器件数量、通态电流经过器件数量、高频开关器件数量、是否需要均压控制等方面,均有一定优势,有助于降低系统复杂度,提高可靠性与变换效率。仿真与实验验证了上述分析。Leakage currents reduce the reliability and the security of non-isolated grid-connected inverters. Three-level topologies based on the dual-polarity modified full bridge inverter or the half bridge inverter were the existing methods to resolve this problem. The use of three-level topologies based on the dual buck inverter is a new way proposed by this paper. As the input divider capacitors of the dual buck half bridge inverter have been replaced by one working period switching bridge, a so-called three-level dual buck full bridge inverter is obtained. Because the voltage of stray capacitor remains unchanged in each half period, there is no leakage current. And there is no shoot-through problem, and none of the body-diodes in this topology needs to work. At the same time, the stresses of devices were reduced, and the outputs of bridge-legs become uni-polarity. The new topology was compared with no leakage current existed topologies. The total number of devices is small, and there is only one power device more than in H5 topology. Currents flow through the least active devices, and working devices, and the least high frequency working devices were used. Voltage balance control is unnecessary. So it is beneficial to the reduction of system complexity, and the improvement of reliability and efficiency. Simulations and experiments verified these analyses.

关 键 词：并网逆变器 漏电流 多电平 双降压式逆变器 

分 类 号：TM464[电气工程—电器]