大规模光伏系统并网对配电网的影响

在环境问题日益恶化和资源危机日益突显的今天,低排放和低污染的可再生能源将逐步成为未来能源市场的发展方向。作为一种可再生能源,光伏发电系统代表着未来能源市场的一个主要发展方向。随着并网安装的光伏发电系统逐渐增多,配电网中可能会经常出现逆向潮流和电网电压超出容许范围的情况。文中分析了在不同季节和气候时的配电网负荷下,导入不同容量的光伏发电系统后电网电压的变化,并通过调节电力变压器分接头,控制起始端电压和终端电压在容许范围之内。同时,从引入光伏发电系统后电网电压的变化以及是否会出现逆向潮流的角度,评估了大规模安装光伏发电系统对原有电网的影响。最后分析了光伏发电系统安装后,电网电力损耗的变化情况。

Influence of Large-scale Grid-connected Photovoltaic System on Distribution Networks

Under the deteriorated condition of environmental issue and resource crisis,the renewable energy with low emission and low pollution becomes the mainstream in the future.Photovoltaic(PV) system,as a kind of renewable energy,represents the future growing market segment.As the penetration level of photovoltaic system rises over the coming decades,reverse power flows on the distribution feeder will occur more frequently and the associated voltage rise might lead to violations of the permissible range of voltage.Various patterns of loads under different weathers and seasons are assumed and node voltages are analyzed by conducting a simulation with different photovoltaic system installation scenarios.The tap is changed to keep sending voltage and terminal node voltage within the permissible ranges continuously.A method is used to evaluate the influence of large-scale installation of photovoltaic generation on distribution networks from the view points of voltage profiles and reverse power flows.Finally,the electrical line losses of feeder with grid-connected photovoltaic system are given.