含高渗透率分布式光伏发电系统的配电网动态等值分析

随着分布式光伏发电系统广泛接入配电网,渗透率不断升高,甚至超过了百分之一百,在光照比较强的时候会向输电网倒送功率,在这种情况下,负荷和分布式光伏发电系统共同主导了配电网的动态特性,对电网的暂态稳定产生了重要的影响。为此,建立了综合考虑负荷及分布式光伏发电系统动态特性的配电网动态等值模型,即在综合负荷模型的基础上增加一个等效的光伏电站,然后通过动态轨迹灵敏度法筛选重要参数,在DIgSILENT-MATLAB联合仿真平台上实现基于遗传算法的关键参数辨识。最后,在DIgSILENT平台中搭建了输配电网仿真算例,仿真结果表明,所提出的配电网动态等值模型能够比较准确地描述含有高渗透率分布式光伏发电系统的配电网动态特性。

Dynamic Equivalence Analysis of Distribution Network Integrated with High-penetration Distributed Photovoltaic Generation System

The penetration level of distributed photovoltaic(PV)generation in the power distribution network has been increasing quickly, and sometimes the penetration level can exceed 100%. The power distribution network even feeds power into the transmission network when sunshine is strong. In this case, the dynamic characteristics of power distribution networks are determined by both the electrical loads and PVs. A dynamic equivalent model for power distribution networks with high penetration of PV is proposed. The proposed equivalent model contains a complex load model and a photovoltaic power station. Moreover, the dynamic trajectory sensitivity method is employed to select key equivalent parameters. Then, on the combined simulation platform of DIgSILENT and MATLAB, genetic algorithm is employed to identify the key parameters of the dynamic equivalent model. Finally, an integrated transmission and distribution network is simulated on DIgSILENT platform, and the simulation results demonstrate that the proposed dynamic equivalent model for distribution networks can ensure the accuracy of the transmission network transient simulation.