高比例分布式电源接入下基于变分模态分解的励磁涌流辨识  

Identification of inrush current based on variational modal decomposition under a high proportion of distributed generation

作　　者：陈春[1] 曹伯仲 曹一家[1] 王玮宇 徐先勇 安义 CHEN Chun;CAO Bozhong;CAO Yijia;WANG Weiyu;XU Xianyong;AN Yi(State Key Laboratory of Disaster Prevention&Reduction for Power Grid,Changsha University of Science and Technology,Changsha 410114,China;State Grid Hunan Electric Power Company Research Institute,Changsha 410007,China;State Grid Jiangxi Electric Power Research Institute,Nanchang 330096,China)

机构地区：[1]长沙理工大学电网防灾减灾全国重点实验室,湖南长沙410114 [2]国网湖南省电力公司电力科学研究院,湖南长沙410007 [3]国网江西省电力有限公司电力科学研究院,江西南昌330096

出　　处：《电力系统保护与控制》2024年第20期94-104,共11页Power System Protection and Control

基　　金：湖南省自然科学基金优秀青年项目资助(2023JJ20039);国家自然科学基金项目资助(52007009)。

摘　　要：分布式电源高渗透并网,呈现出运行复杂性与非线性,故障电流谐波特征显著,使得传统继电保护难以准确区分励磁涌流与故障电流。因此,首先分析了光伏与双馈风机接入产生谐波的表达式,推导了励磁涌流产生机理及谐波特性,并总结了励磁涌流与短路电流频率分量占比。据此,充分发挥变分模态分解(variational mode decomposition,VMD)避免模态混叠的优势,采用VMD算法将故障电流分解为不同中心频率模态分量,比较不同模态方差贡献率进而辨识励磁涌流。仿真结果表明:所提辨识方法在不同故障类型、不同种类分布式电源以及不同合闸角等条件下均能准确地辨识,且辨识能在故障发生一个周波内完成,灵敏度高。Because of the high penetration of distributed generation(DG),the operation of DG is complex and nonlinear,and the harmonic characteristics of fault current are significant.This makes it difficult for traditional relay protection to accurately distinguish between inrush and fault current.Therefore,this paper first analyzes the expression of harmonics generated by photovoltaics and a doubly-fed wind turbine,deduces the generation mechanism of inrush current and harmonic characteristics,and summarizes the proportion of each frequency component of inrush and short-circuit current.Taking full advantage of variational mode decomposition(VMD)to avoid mode aliasing,the fault current is decomposed into different central frequency modes using the VMD algorithm,and the magnetizing inrush current is identified by comparing the variance contribution of different modes.The simulation results show that the proposed identification method can accurately identify the fault in conditions of different fault types,types of distributed generation and switching angles,and the identification can be completed within one cycle of the fault with high sensitivity.

关 键 词：分布式电源 励磁涌流 变分模态分解 方差贡献率 

分 类 号：TM73[电气工程—电力系统及自动化]