基于序故障分量的Sen变压器纵联保护研究  

Pilot Protection for Sen Transformer Based on Sequence Fault Components

作　　者：谢舒帆 荣娜[1] 郭西 XIE Shufan;RONG Na;GUO Xi(School of Electrical Engineering,Guizhou University,Guiyang 550025,Guizhou,China)

机构地区：[1]贵州大学电气工程学院,贵州贵阳550025

出　　处：《电网与清洁能源》2023年第5期56-65,共10页Power System and Clean Energy

基　　金：贵州省科学技术基金项目(2021277);贵州省优秀青年科技人才项目(20215645)。

摘　　要：Sen变压器(Sen transformer,ST)是一种功能强大的电磁式统一潮流控制器。目前对于ST的研究多集中于其拓扑结构变种和模型建立等方面,而对ST的保护系统研究较少。作为一种电磁式潮流控制装置,ST存在传统变压器的励磁涌流、CT饱和等问题。另外,ST特有的补偿电压以及串联绕组饱和现象对其保护的可靠性有着更高的要求。为此,通过分析ST区内外故障时虚拟阻抗的特征差异,提出一种基于故障分量虚拟阻抗的ST保护方法。该方法基于ST两端序电压与序电流故障分量之比构造了虚拟阻抗作为动作量,利用故障前电气量构建了自适应制动阈值,并针对ST的空充过程进行了分析和修正。PSCAD/EMTDC和MATLAB仿真实验结果表明了该方法能够可靠快速地识别各类ST区内外故障,且不受励磁涌流、补偿绕组饱和以及CT饱和的影响。Sen transformer(ST)is a powerful electromagnetic unified power flow controller.At present,most of the research on the ST is focused on its topology variants and model building,while less research has been done on the protection system of the ST.As an electromagnetic power flow control device,the ST has problems such as excitation inrush current and CT saturation of conventional transformers.In addition,the unique compensating voltage and series winding saturation of the ST have higher requirements on the reliability of its protection.In this paper,an ST protection method based on fault component virtual impedance is proposed by analyzing the characteristic difference of the virtual impedance when the ST is in and out of fault zone.The virtual impedance is constructed as the action quantity based on the ratio of positive or negative sequence voltage and current fault components at both ends of the ST,and the adaptive braking threshold is constructed by using the pre-fault electrical quantities,which is analyzed and corrected for the no-load excitation of the ST.PSCAD/EMTDC and MATLAB simulations verify that the proposed method can reliably and quickly identify various types of faults inside and outside the ST zone,and is not affected by inrush current,series winding saturation and CT saturation.

关 键 词：柔性交流输电系统(FACTS) Sen变压器 UPFC 虚拟阻抗 故障分量 纵联保护 

分 类 号：TM772[电气工程—电力系统及自动化]