大规模光伏接入配电网电压波动越限抑制研究

Research on Voltage Fluctuations and Over-Limit Suppression of Large-Scale Photovoltaic Access to Distribution Networks

为了抑制光伏接入配电网的电压波动以及降低网损,研究一种大规模光伏接入配电网电压波动越限抑制方法。通过分析光伏接入配电网电压波动越限原因,计算光伏接入时配电网负荷的无功功率和有功功率,获得电压偏差数值和越限数值;利用基于单时间断面无功优化的电压越限抑制方法,完成光伏接入配电网电压波动越限抑制过程。实验结果表明:该方法可有效减小配电网支路节点位置的电压波动区间,使电压波动数值远离上、下限;可有效降低光伏设备输出的无功功率,使配电网网损率由15%左右下降至3%左右,应用效果显著。

In order to suppress voltage fluctuations and reduce network losses caused by photovoltaic(PV)access to the distribution network,a method for suppressing voltage fluctuations and over-limit in distribution networks with large-scale PV integration is presented in this paper.By analyzing the causes of voltage fluctuations and over-limit when PV is connected to the distribution network,the reactive power and active power of the distribution network load during photovoltaic access are calculated,and the voltage deviation value and the limit value are obtained;and the voltage over-limit suppression method based on the reactive power optimization of a single time section is used to realize the over-limit suppression process of the voltage fluctuation of photovoltaic access to the distribution network.The experimental results show that:this method can effectively reduce the voltage fluctuation range at the branch node positions of the distribution network,keeping the voltage fluctuation values away from the upper and lower limits;and it can effectively reduce the reactive power output by PV devices,reducing the distribution network loss rate from about 15%to about 3%,with significant application effects.