基于单端电流暂态量的柔性直流配电网保护及其整定  

Protection of Flexible DC Distribution Network Based on Single-end Current Transient and Its Setting

作　　者：贾科 陈聪 刘子奕 施志明 陈淼 毕天姝 JIA Ke;CHEN Cong;LIU Ziyi;SHI Zhiming;CHEN Miao;BI Tianshu(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Beijing 102206,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市102206

出　　处：《电力系统自动化》2022年第6期144-152,共9页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(2018YFB0904104)。

摘　　要：柔性直流配电网可以高效连接分布式电源和直流负荷。然而直流配电网双极短路故障时电流上升迅速且峰值高,如何通过保护间相互配合在短时内准确识别并切除故障区域成为亟待解决的关键问题。文中根据直流配电网中DC/DC换流器对暂态电流高频信息的边界效应,使用离散小波变换提取电流高频分量,进而构造一种通过保护定值进行配合的两段式单端量保护,可快速、可靠地识别故障区域。在PSCAD/EMTDC仿真平台上搭建配有直流断路器的辐射状柔性直流配电网模型,仿真分析结果表明所提保护方法能快速、准确识别并切除故障线路。Flexible DC distribution network can efficiently connect distributed generators and DC loads. However, in the case of bipolar short-circuit fault in DC distribution networks, the current rises rapidly and its peak value is high. How to accurately identify and remove the fault area in a short time through the cooperation between protections has become a key problem to be solved.According to the boundary effect of DC/DC converters on the high-frequency information of transient current in DC distribution networks, this paper uses discrete wavelet transform to extract the high-frequency component of the current, and then constructs a two-stage single-end protection coordinated by protection setting value, so as to quickly and reliably identify the fault area. A radial flexible DC distribution network model with DC circuit breaker is built on PSCAD/EMTDC simulation platform. The simulation results show that the proposed protection method can quickly and accurately identify and remove the fault line.

关 键 词：直流配电网 故障识别 DC/DC换流器 离散小波 整定配合 

分 类 号：TM721.1[电气工程—电力系统及自动化]