Time-domain Differential Protection Based on Operating and Restraining Trajectory Indices for Lines Connecting Battery Storage Energy Stations  

作　　者：Yingyu Liang Cunyue Pan 

机构地区：[1]School of Mechanical and Electrical Engineering,China University of Mining and Technology(Beijing),Beijing,China

出　　处：《Journal of Modern Power Systems and Clean Energy》2024年第4期1074-1086,共13页现代电力系统与清洁能源学报（英文）

基　　金：supported in part by the National Natural Science Foundation of China (No.52277132);in part by the Fundamental Research Funds for the Central Universities (No.2024JCCXJD01)

摘　　要：Battery energy storage stations(BESSs)pose sever-al challenges for both phasor-based differential protection and the newly-proposed time-domain differential protection.These challenges include low sensitivity and even rejection.Besides,the negative impact of various nonideal conditions,including current transformer(CT)saturation,errors,and outliers,on the security of differential protection remains an important problem.Motivated by the aforementioned issues,this study accounts for the trajectory distribution discrepancy on Cartesian plane under various conditions and proposes a time-domain differential protection method.In this paper,the trajectory formed by operating and restraining current samples is devel-oped.Subsequently,after considering different operating states,the fault severity levels,and nonideal conditions,the variances in trajectory distribution between internal and external faults are extensively analyzed.On this basis,the Cartesian plane is divided into operating,uncertainty,and restraining zones.Further,the operating and restraining trajectory indices are meticu-lously designed and a protection criterion based on these indices is formed to accurately separate internal faults from other events,unaffected by CT saturation,errors,and outliers.The exceptional performance of the proposed protection method is extensively validated through PSCAD simulations and a hard-ware-in-the-loop testing platform.Regarding the dependability,sensitivity,and security,the proposed protection method outper-forms three state-of-the-art differential protection methods.

关 键 词：Battery energy storage station time-domain differential protection operating trajectory index(OTI) restraining trajectory index(RTI) 

分 类 号：TM912[电气工程—电力电子与电力传动] TM773