分布式光伏接入对配电网电压影响及工程计算

The Influence of Distributed Photovoltaic Access on Distribution Network Voltage and ts Engineering Calculation

在分布式光伏接入配电网后,随着分布式光伏功率的注入会导致配电网潮流发生变化,进而引发节点电压变化的问题。为了便于工程计算配电网不同节点电压及分布式光伏接入对配电网节点电压影响的大小,本文基于配电网潮流分析,首先采用因素拆分和效果叠加的方法,通过拆分系统电源和分布式光伏电源对配电网不同节点电压的影响;然后将两者产生的影响效果进行叠加求和,形成光伏接入下配电网节点电压变化模型;同时为了贴合工程应用,考虑配电网的运行条件及拓扑结构,在忽略了线路电抗及无功功率的情况下,构建了节点电压变化的简化分析模型。最后采用IEEE33节点系统对模型进行仿真验证,验证结果说明了模型能够更快速且较为准确的计算出节点电压,具有较高的实用性和可靠性。同时也仿真得出了不同光伏接入情况下配电网节点电压变化趋势。

After the distributed photovoltaic is connected to the distribution network,the powerflow of the distribution network will change with the injection of distributed photovoltaic power,which will lead to the change of node voltage.In order to facilitate the engineering calculation of the influence of different node voltages of distribution network and distributed photovoltaic access on the node voltage of distribution network,based on the powerflow analysis of distribution network,the method of factor splitting and effect superposition is adopted in this paper.By splitting the influence of system power supply and distributed photovoltaic power supply on different node voltages of distribution network.Then the effects of the two are superimposed and summed up to form the node voltage change model of the distribution network under photovoltaic access;at the same time,in order tofit the engineering application,the operation conditions and topology of the distribution network are considered.In the case of ignoring line reactance and reactive power,a simplified analysis model of node voltage change is constructed.Finally,the IEEE33 node system is used to simulate and verify the model,and the results show that the model can calculate the node voltage more quickly and accurately,and has high practicability and reliability.At the same time,the changing trend of node voltage in distribution network under different photovoltaic access is obtained by simulation.