含逆变型分布式电源花瓣式配电网单相接地故障特性分析  

Analysis of single-phase grounding fault characteristics in petal-shaped distribution network with inverter-interfaced distributed generator

作　　者：陈晓龙[1] 袁姝 李永丽[1] 李仲青[2] 王强 耿少博 CHEN Xiaolong;YUAN Shu;LI Yongli;LI Zhongqing;WANG Qiang;GENG Shaobo(Key Laboratory of Smart Grid of Ministry of Education,Tianjin University,Tianjin 300072,China;China Electric Power Research Institute,Beijing 100192,China;State Grid Hebei Electric Power Co.,Ltd.,Shijiazhuang 050000,China)

机构地区：[1]天津大学智能电网教育部重点实验室,天津300072 [2]中国电力科学研究院,北京100192 [3]国网河北省电力有限公司,河北石家庄050000

出　　处：《电力自动化设备》2022年第4期129-137,共9页Electric Power Automation Equipment

基　　金：国家电网有限公司总部科技项目(适应灵活可控源荷接入的新型城市电网继电保护关键技术研究及应用)。

摘　　要：花瓣式配电网具有高供电可靠性,但闭环运行模式和逆变型分布式电源接入使其故障特性变得更加复杂。针对含逆变型分布式电源花瓣式配电网的单相接地故障,利用对称分量法推导了故障点接地电流、故障相电流及线路各序电流的公式,并揭示了各电流的变化规律,然后通过仿真对分析结果的正确性进行了验证。结果表明,随故障点按顺时针方向沿花瓣式环网移动,故障点上游侧线路的各序电流及故障相电流幅值呈减小趋势,故障点下游侧线路的各序电流及故障相电流幅值呈增大趋势;逆变型分布式电源并网点与变电站母线之间非故障线路上的负序电流幅值单调递增、相位基本不变,而该线路上的正序电流、零序电流及故障点所在相的相电流则由于相位发生约180°的改变导致其幅值呈现先减小后增大的趋势。在此基础上,对基于幅值或相位的电流差动保护和零序方向过电流保护在花瓣式配电网中的适用性进行探讨,并给出了相应改进建议。The petal-shaped distribution network has high power supply reliability.However,the closed-loop operation mode and the access of IIDG(Inverter-Interfaced Distributed Generator) makes the distribution network has more complex fault characteristics.In order to study the characteristics of single-phase grounding fault in petal-shaped distribution network with IIDG,the formulas for grounding current at fault location,fault phase current and sequence current are derived by using the symmetrical component method,and the variation trends of the above currents are analyzed.The analytical results are verified by simulation.The results show that as the fault location move clockwise along the petal-shaped loop line,the amplitude of sequence currents and fault phase current on the upstream side of the fault location decrease and those on the downstream side increase.For the non-faulty line between the PCC(Point of Common Coupling) of IIDG and the substation busbar,the amplitude of the negative-sequence current increases monotonously,while that of the positive-sequence current,zero-sequence current and fault phase current all show a trend of decreasing first and then increasing due to a phase change of about 180°.On this basis,the applicability of current differential protection based on amplitude or phase and zero-sequence direction over-current protection in petal-shaped distribution network is discussed,and some suggestions for improvement are given.

关 键 词：花瓣式配电网 逆变型分布式电源 单相接地故障 故障特性分析 保护适用性 

分 类 号：TM711[电气工程—电力系统及自动化]