一种微源逆变器串联连接型微网特性研究

Study on characteristics of a microgrid with micro source inverters connected in series

为进一步降低微网输出电压谐波含量,减少对外电网的谐波污染,研究了一种微源逆变器串联连接的微网组网方式。首先介绍了系统拓扑结构及输出电压双重傅里叶表达式,并基于此对系统特性进行了详细分析。其次对直流环节电压波动、孤网运行时功率分配及微源实时投切等问题提出了相应的解决方法。最后建立微源数学模型,利用Matlab/Simulink软件对系统运行特性进行了仿真分析。该结构下微电网在减少输出谐波含量的同时,可有效解决微网中环流、频率差异等诸多问题,提高传统电网对分布式电源的接纳能力,并能够对微电网的全面发展提供新思路和新方向。

In order to reduce the output voltage harmonic content of microgrids and utility grid harmonic pollution, a kind of microgrid whose micro source inverters are connected in series is proposed. Firstly, the system topology structure, double Fourier expression of output voltage and the characteristics of the system are introduced in detail. Secondly, corresponding solutions to problems of DC link voltage fluctuation, power distribution and micro source real-time pitch cutting are put forward. Lastly, according to the mathematical model of the micro source, operating characteristics of the system are simulatecl and analyzed using Matlab/Simulink soft-ware. While reducing the output harmonic content, the special structure of microgrids solves the problems of circulation and frequency difference. The system improves the acceptance ability of traditional grid for distributed power, providing a new idea and new direction for all-round development of microgrids. This work is supported by National Natural Science Foundation of China （No. 51047010）.