基于改进极模变换的柔性直流输电系统断线故障分析与辨识  

Analysis and Identification of Line Breakage Fault for Flexible DC Transmission System Based on Improved Pole-mode Transformation

作　　者：郑宗生 张巍[1] 廖建权 周念成[2] 王渝红[1] 王强钢[2] ZHENG Zongsheng;ZHANG Wei;LIAO Jianquan;ZHOU Niancheng;WANG Yuhong;WANG Qianggang(School of Electrical Engineering,Sichuan University,Chengdu 610000,China;State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Chongqing 400044,China)

机构地区：[1]四川大学电气工程学院,四川省成都市610000 [2]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市400044

出　　处：《电力系统自动化》2024年第5期137-145,共9页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(52207126);国家自然科学基金委员会-国家电网公司智能电网联合基金资助项目(U22B6006)。

摘　　要：断线故障的故障特性分析是制定断线保护方案的基础。首先,文中以金属回线双极直流系统为对象,根据直流系统中模块化多电平换流器(MMC)在故障前后的状态变化,基于叠加定理得出MMC在直流系统发生故障时的等效电路模型,构建直流系统断线故障下的等效电路。然后,通过改进极模变换矩阵推导其在不同故障类型下的复合模量等值网络,分析不同断线故障的模量特征;在此基础上,利用2模和0模电流的变化量构建断线故障类型识别的相平面,实现断线故障的分类;同时,提出基于1模电流变化量的区内外断线故障辨识流程。最后,在PSCAD/EMTDC中建立了仿真模型,验证了所提保护方法的快速性和可靠性。The analysis of fault characteristics of line breakage fault is the basis of developing line breakage protection scheme.First,taking the metal return line bipolar DC system as the object,according to the state changes of modular multilevel converter(MMC) in the DC system before and after faults,the equivalent circuit model of MMC in the DC system when the fault occurs is obtained based on the superposition theorem,and the equivalent circuit under the line breakage fault of the DC system is constructed.Then,by improving the pole-mode transformation matrix,the composite modulus equivalent network under different fault types is derived to analyze the modulus characteristics of different line breakage faults.On this basis,the phase plane of line breakage fault type identification is constructed by using the change of 2-mode and 0-mode current,and the classification of line breakage faults is realized.Furthermore,the process of line breakage fault identification based on the change of 1-mode current is proposed.Finally,the simulation model is established in PSCAD/EMTDC,and the rapidity and reliability of the proposed protection method are verified.

关 键 词：柔性直流 断线故障 极模变换 模块化多电平换流器 

分 类 号：TM721.1[电气工程—电力系统及自动化]