大容量分布式光伏并网对配电网综合影响分析

Integrated Impact of Large-capacity Distributed Photovoltaic on Power Grid

为研究大容量分布式光伏并网对配电网的综合影响,基于广东某实际并网的分布式光伏项目的数据,搭建了DIg SILENT模型,分别从潮流和短路、谐波和三相不平衡度、电压波动等角度,对分布式光伏在不同并网点处并网前后配电网的表现进行仿真和对比分析。结果表明,为应对大规模分布式光伏发电接入配电网,需加强并网检测和控制并网容量,以保证配电网线路轻载甚至倒送、公共点功率因素偏低、短路电流增加和电能质量恶化等问题限制在规定允许范围内。

To study the integrated impact of large capacity distributed photovoltaic （PV） on the distribution network, the models on DIgSILENT platform are constructed based on the data of a practical grid-connected distributed PV proj- ect in Guangdong Province. The simulation is conducted from the perspective of load flow, short circuit, three-phase un- balanced degree, harmonic and voltage fluctuation at the points of common coupling （PCC）to compare the performances of distribution network before and after PV connection. The results show that in response to the increasing scale of distributed PV connected to the distribution network, the grid-connection tests and installed capacity control of distributed PV should be strengthened to restrict the problems of light load and inverse active power of transmission lines, low power factor at PCC, short-circuit current enlargement and deteriorating power quality within allowable extent.