摘要
针对传统Z源拓扑所存缺陷,提出一种改进型Z源拓扑。该拓扑中,用耦合电感代替传统结构中与电源正极相连的电感,阻抗网络相对于三相逆变桥位置发生改变;此外在直流链处增加全控型IGBT器件,用于单独插入直通零矢量。分析其在电压型和电流型模式的工作状态可知:相比于传统Z源逆变器,在电压型模式工作时,该拓扑可实现更高的电压增益,稳态时电容电压应力更低且不存在启动冲击电流,逆变侧输出电压波形质量更高;在电流型模式工作时,其启动压降较低,逆变侧输出电流波形质量较高。最后为实现对该逆变器的并网控制,在两相旋转坐标系下建立系统数学模型,运用两电流环和一电压环实现其高功率因数并网。算例结果验证了所提策略的有效性。
To overcome shortcomings of traditional Z-source inverter, an improved z-source inverter topology is proposed. For this topology, a controlled device IGBT is introduced to realize separation between shoot-through zero vector and traditional zero vector, and then a coupled inductor is used to replace one of inductors connected to positive pole of power supply. Its position relative to three-phase inverter bridge is changed. Compared to traditional z-source inverter, it obtains higher boost factor and lower capacitor voltage stress for steady state and higher quality of its AC output voltage when working in voltage mode. In addition, no inrush current exists at startup. The same efficiencies are maintained for its working in current mode. Finally, mathematical system model is established in two-phase rotating coordinate system. Voltage loop and two current loops are used to connect it to grid with high power factor. Results of calculation examples verify effectiveness of proposed control strategy.
出处
《电网技术》
EI
CSCD
北大核心
2015年第12期3477-3484,共8页
Power System Technology
基金
国家自然科学基金项目(61263004)
甘肃省自然科学基金(1212RJZA071)~~
关键词
Z源拓扑
直通零矢量
耦合电感
并网控制
Z-source inverter
shoot-through vector
coupled inductor
grid connection control
