一种新型交直流混合微电网互联变流器

A New Interlinking Converter for AC/DC Hybrid Micro-Grid

基于隔离式准Z源拓扑的双向AC/DC拓扑不仅具有高功率密度、低成本、较小体积等优势,且通过三相逆变器的桥臂直通实现升压以避免死区设置引起的波形畸变、效率降低等,可以替代传统电压源型逆变器作为交直流混合微电网中的互联变流器。首先介绍了交直流混合微电网的典型拓扑,分析了隔离式双向AC/DC互联变流器工作原理,随后设计了并网模式及离网模式的控制方式、脉冲调制方式。用MATLAB/Simulink软件进行了仿真验证,仿真结果证明该电路拓扑的有效性及控制策略的可行性。

The bidirectional AC/DC topology based on isolated quasi-Z source topology not only has the advantages of high power density,low cost and small volume,but also realizes the boost ability through the bridge arm shoot-through of the three-phase inverter to avoid the waveform distortion and efficiency reduction caused by the dead zone setting. Thus,it will be an attractive alternative to the conventional voltage source converter in hybrid micro-gird as interlinking converter. This paper firstly introduced the typical topology of AC/DC hybrid micro-grid,then analyzed the operating principle of the isolated bidirectional AC-DC bidirectional converter. Subsequently,the control strategy of grid-connected mode and off-grid mode,and the pulse modulation were designed. Finally,the MATLAB/Simulink software was used to verify the validity of the topology and the feasibility of the control strategy.