适用于柔直配电网的暂态高频阻抗纵联保护  

Transient High-frequency Impedance Pilot Protection for Flexible DC Distribution Network

作　　者：张啸 房鑫炎 ZHANG Xiao;FANG Xinyan(Key Laboratory of Control of Power Transmission and Conversion(Ministry of Education),School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学电子信息与电气工程学院电力传输与功率变换控制教育部重点实验室,上海200240

出　　处：《电力系统及其自动化学报》2023年第9期1-9,共9页Proceedings of the CSU-EPSA

基　　金：国家自然科学基金资助项目(U1866206);国网公司资助项目(5211JY19000Q)。

摘　　要：为保障柔性直流配电网的安全可靠运行,本文提出一种基于暂态高频阻抗的纵联保护方法。通过建立直流线路的故障等效电路,分析直流线路极间故障后数个毫秒内暂态电气量的变化特征,采用小波变换提取电压、电流故障分量中特定频段的高频信号,并计算保护装置安装处的高频阻抗,利用保护区内、外故障时暂态高频阻抗较大的幅值差异构成保护。该方法对信号同步的要求不高,相邻线路间的主保护还可以通过配合构成新的区域后备保护。最后,本文在PSCAD/EMTDC平台搭建模型进行仿真,结果表明,本文所提方法能够快速准确地动作。To ensure the safe and reliable operation of flexible DC distribution network,a pilot protection method based on transient high-frequency impedance is proposed in this paper.Through the establishment of a fault equivalent circuit of the DC line,the variation characteristics of transient electrical quantity within several milliseconds after the DC line pole-to-pole fault are analyzed.The high-frequency signal of a specific frequency band in the voltage and current fault components is extracted by using the wavelet transform to calculate the high-frequency impedance at the installation po⁃sition of protection device.The large amplitude difference between transient high-frequency impedance under faults in⁃side and outside the protected area is used to constitute the protection.This method does not have high requirements for signal synchronization,and a new regional reserve protection can also be formed through the cooperation of adjacent lines.Finally,simulations are carried out on the PSCAD/EMTDC platform,and results show that the proposed method can be performed quickly and accurately.

关 键 词：柔性直流配电网 直流线路故障 暂态高频阻抗 纵联保护 区域保护 

分 类 号：TM771[电气工程—电力系统及自动化]