Zero-Voltage-Transition Full-Bridge Topologies for Transformerless Photovoltaic Grid-Connected Inverter
Zero-Voltage-Transition Full-Bridge Topologies for Transformerless Photovoltaic Grid-Connected Inverter
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DOI：
10.1109/tie.2014.2300044
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发表时间：
2014-01
影响因子：
7.7
通讯作者：
Huafeng Xiao;Xi P. Liu;Ke Lan
中科院分区：
文献类型：
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作者：
Huafeng Xiao;Xi P. Liu;Ke Lan
低漏电流和高效率是无变压器光伏并网逆变器的两个关键指标。无变压器逆变器拓扑由于省去了Transformer而具有上级效率，但目前其开关管仍处于硬开关状态。针对全桥无变压器光伏并网逆变器拓扑结构，提出了一种新的零电压转换（ZVT）概念。通过引入两个谐振回路，实现了高频主开关管的零电压开通和关断，辅助开关管的零电流开通，以及工频开关管反并联二极管的零电压开通和关断。以ZVT-H6-I为例。详细分析了谐振回路的工作原理、软开关条件、占空比限制和参数设计原则。最后，ZVT的概念的有效性进行了验证，额定在100 kHz和1 kW的ZVT-H6-I原型。
Low leakage current and high efficiency are two key indexes for the transformerless photovoltaic (PV) grid-connected inverter. The transformerless inverter topologies have superior efficiency owing to saving the transformer, but their switches are still on a hard-switching state at present. This paper presents a novel zero-voltage transition (ZVT) concept for the full-bridge transformerless PV grid-connected inverter topologies. The zero-voltage turn-on and turnoff of the high-frequency main switches and the zero-current turn-on of the auxiliary switches, as well as the zero-voltage turn-on and turnoff of the antiparallel diodes of the line-frequency switches, are realized by introducing two resonant tanks. Take ZVT-H6-I for example. The operation principle, soft-switching conditions, duty cycle restriction, and parameter design rule of the resonant tank are analyzed in detail. Finally, the validity of the ZVT concept is verified by a ZVT-H6-I prototype rated at 100 kHz and 1 kW.