含分布式光伏的中压直流配电网接地故障暂态特性分析  

Analysis of grounding fault transient characteristics of medium-voltage DC distribution network with distributed photovoltaic

作　　者：何东 徐明章 兰征 王伟[2] 曾进辉[1] 余雪萍 HE Dong;XU Mingzhang;LAN Zheng;WANG Wei;ZENG Jinhui;YU Xueping(College of Electrical and Information Engineering,Hunan University of Technology,Zhuzhou 412007,China;College of Electrical and Information Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南工业大学电气与信息工程学院,湖南株洲412007 [2]湖南大学电气与信息工程学院,湖南长沙410082

出　　处：《电力自动化设备》2023年第11期43-50,共8页Electric Power Automation Equipment

基　　金：湖南省自然科学基金资助项目(2021JJ40172)。

摘　　要：针对分布式光伏接入直流配电网后故障电流分布呈现新特征的问题,以含分布式光伏的中压直流配电网为研究对象,分析直流母线发生单极接地故障时的故障暂态特征和影响机理。单极接地故障响应过程可以分为直流侧电容放电、光伏电源多回路供电、光伏电源续流以及电感续流4个阶段,并根据4个阶段的暂态特性推导得到了各故障阶段中各个变换器直流侧电容电压以及故障电流的时域表达式。通过分析故障电流的典型特征可以发现单极接地的故障电阻大小对故障电流的幅值和到达峰值的时间影响较大。最后在PSCAD/EMTDC仿真软件中搭建含分布式光伏的±10 kV双端供电型直流配电网仿真模型,验证了含分布式光伏的中压直流配电网单极接地故障暂态特性理论分析的正确性。When the distributed photovoltaic(PV)is connected to the direct current(DC)distribution network,the fault current distribution presents new characteristics.For this,the transient characteristics and influence mechanism of single pole grounding fault of DC-bus in medium-voltage DC distribution network with distributed PV are analyzed.The single pole grounding fault response process is divided into four stages:DC-side capacitor discharging stage,PV generator multiloop power supplying stage,PV generator freewheeling stage and inductance freewheeling stage.Based on the transient characteristics of the above four stages,the time domain expressions of the DC-side capacitor voltage and fault current in the process of each fault stage are derived.By analyzing the typical characteristics of fault current,it can be found that the magnitude of the fault resistance has a great influence on the amplitude of the fault current and the time to reach the peak.Finally,a simulation model of±10 kV double-terminal DC distribution network with distributed PV is built in PSCAD/EMTDC,which verifies the correctness of the theoretical analysis.

关 键 词：分布式光伏 直流配电网 接地故障 故障电流 故障特征 

分 类 号：TM71[电气工程—电力系统及自动化]