基于基频调制电流源换流器的直流线路全线速动保护  

DC Transmission Line Whole-line Quick Protection of Fundamental Frequency Modulation-based Current Sourced Converter

作　　者：袁帅 付丰豪 陈力绪 赵成勇 贾秀芳 YUAN Shuai;FU Fenghao;CHEN Lixu;ZHAO Chengyong;JIA Xiufang(State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources(North China Electric Power University),Changping District,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),北京市昌平区102206

出　　处：《中国电机工程学报》2023年第14期5596-5606,共11页Proceedings of the CSEE

摘　　要：基频调制电流源换流器(fundamental frequency modulation-based current sourced converter,FFM-CSC)作为一种新型电流源换流器,能够解决传统直流输电工程面临的换相失败及无功消耗问题,兼具电流源和电压源换流器部分优势。直流线路接地作为直流系统中几乎最严重的故障,针对FFM-CSC换流站短路过程研究缺乏定量分析,不利于系统参数设计和故障保护识别,限制了FFM-CSC的推广应用。论文针对双极12脉动FFM-CSC系统,建立短路故障等效电路,推导故障初期过电流的解析计算公式;并针对直流线路短路特点,提出基于单端监测量的保护算法,可作为直流线路主保护。该算法计算要求低,数学原理清晰,可随系统参数和运行工况的改变灵活调整。最后,基于PSCAD/EMTDC仿真软件搭建FFM-CSC直流系统详细模型,验证数学表达式准确性,同时证明保护算法的安全可靠性。The fundamental frequency modulation-based current source converter(FFM-CSC)is a new type of current source converter.It solves the problems of commutation failure and reactive power consumption encountered in traditional DC transmission.It combines the advantages of current source and voltage source converter.DC line grounding is nearly the most serious fault in DC systems.Research on the FFM-CSC converter station short circuit process lacks quantitative analysis,hindering system parameter design,fault protection identification,and FFM-CSC adoption.This paper establishes an equivalent circuit for short-circuit faults in a bipolar 12-pulse FFM-CSC system and derives an overcurrent calculation formula for the initial fault stage.Based on short-circuit fault characteristics,it proposes an overcurrent protection algorithm based on single-end monitoring to be the primary protection for the entire DC line.The algorithm has low calculation requirements,a clear mathematical principle,and can flexibly adjust to system parameter and operating condition changes.Finally,it uses PSCAD/EMTDC simulation software to build a detailed FFM-CSC DC system model to verify the mathematical expression’s accuracy and the protection algorithm’s safety and reliability.

关 键 词：电流源换流器 短路故障特性 全线速动 电流突变量 保护整定 

分 类 号：TM721[电气工程—电力系统及自动化]