摘要
新型电力系统电源侧含有高比例新能源电源,受其状态多样性、布置分散性、输出非线性等影响,电网故障期间短路电流水平下降且不确定性增强,给传统电流保护的整定配合造成困难。为此,结合传统三段式电流保护,提出了一种基于实时生成定值的自适应电流保护方法。该方法计及新能源实际故障输出而生成定值,包括:首先,建立能区分新能源和发电机不同输出特性的等效电源模型,故障前对短路前后不变的模型参数持续辨识;故障发生后,结合就地测量信息获取等效电源模型的变化参数;然后,基于实际故障场景和故障期间新能源实际输出,对分段式电流保护进行实时整定;最后,结合测量值与整定值进行动作判断。故障前的持续辨识,保证了发电机与新能源的有效分离;基于实际故障场景生成定值可计及新能源的整体输出作用,有效应对其分散性、多样性与非线性问题。通过算例对比与分析,验证了所提自适应电流保护方法的可行性与正确性。
The power sides of new power systems contain a large proportion of new energy sources.Owing to various types,distributed locations,and nonlinear outputs,the through-current level of the short circuit decreases,and its uncertainty increases when a fault occurs in the power grid,which makes it difficult for traditional current protection to preset and trip.Therefore,an adaptive current protection method based on real-time generated settings using local information is proposed,referring to traditional three-stage current protection.This method considers the actual fault characteristics of new energy sources to generate a preset.First,an equivalent source model is established that can distinguish the different outputs of new energy sources between generators and identify them online to obtain the unchanged parameters before and after the fault.Then,after a fault occurs,the local measured information is used to obtain the changeable parameters.Subsequently,preset values were generated in real-time based on the actual fault scenario and the actual output of new energy sources during the fault.Finally,the trip is decided based on the measured current and the preset value.Continuous identification before a fault occurs can effectively separate generators and new energy sources in the model.Online presetting based on actual fault scenarios and the output of new energy sources can effectively solve the problems of variety,distribution,and nonlinearity.The feasibility and correctness were verified by both analysis and comparison of various cases.
作者
张政伟
陈谦
牛应灏
冯源
朱嘉傲
ZHANG Zhengwei;CHEN Qian;NIU Yinghao;FENG Yuan;ZHU Jiaao(College of Energy and Electrical Engineering,Hohai University,Nanjing 211100,China)
出处
《电力建设》
CSCD
北大核心
2024年第2期137-146,共10页
Electric Power Construction
基金
国家自然科学基金项目(51837004)。
关键词
新型电力系统
新能源电源
电流保护
实时定值
等效电源模型
new power system
new energy source
current protection
real-time protection settings
equivalent source model