基于临界故障时刻的换相失败预测方法  

Commutation Failure Prediction Considering Critical Fault Moment

作　　者：张艳霞[1] 卢静怡 张富贺 毕安露 ZHANG Yanxia;LU Jingyi;ZHANG Fuhe;BI Anlu(Key Laboratory of Smart Grid(Tianjin University),Ministry of Education,Nankai District,Tianjin 300072,China)

机构地区：[1]智能电网教育部重点实验室(天津大学),天津市南开区300072

出　　处：《电网技术》2021年第10期4066-4075,共10页Power System Technology

摘　　要：换相失败是高压直流输电系统的一种常见故障,换相失败预测对于后期抑制换相失败、保证系统的安全运行具有积极意义。从换相机理出发分析了换相电压、直流电流与关断角的关系;在此基础上研究故障发生时刻对换相失败的影响,定义了临界故障时刻的概念,分别推导换相期间和非换相期间临界故障时刻的解析表达式,建立了关断角与临界故障时刻的定量关系,提出了一种基于临界故障时刻的换相失败预测新方法。为进一步求取临界故障时刻,采用牛顿插值法构造了求解临界故障时刻所需的换相起始时刻和结束时刻的直流电流和函数。基于CIGRE标准测试模型,在PSCAD/EMTDC中对所提换相失败预测判据进行验证。结果表明,所提出的换相失败预测方法能够较为准确地预测故障后换相情况,证明了所提判据的有效性。Commutation failure is a common fault in the HVDC transmission system.The prediction of commutation failure is of positive significance for subsequently suppressing commutation failures and ensuring the safe operation of the system.Based on the commutation mechanism,this paper analyzes the relations between the commutation voltage,the DC current,and the extinction angle.Furtherly,this paper studies the influence of the fault initiation moment on the commutation failure.The analytical expressions of the critical fault moments during the commutation process and the non-commutation process are derived.The quantitative correlation between the fault initiation moment and the extinction angle is established.A novel method of the commutation failure prediction considering the critical fault moment is proposed.In order to further obtain the critical fault moment,the Newton interpolation method is utilized to construct the sum function of the DC current at the beginning and the ending moment of the commutation.Based on the CIGRE Benchmark HVDC model,the proposed commutation failure prediction criterion is verified on the PSCAD/EMTDC.The simulation results show that the proposed commutation failure prediction method is able to correctly predict the commutation failure after a fault occurs,which proves the effectiveness of the proposed criterion.

关 键 词：高压直流输电 换相失败预测 临界故障时刻 直流电流 

分 类 号：TM721[电气工程—电力系统及自动化]