基于电流突变量曲线拟合的故障时刻检测算法  

Fault instant detection algorithm based on curve fitting of phase current increments

作　　者：董金金 高厚磊[1] 李娟 刘星[3] DONG Jinjinj , GAO Houlei1, LI Juan2, LIU Xing3(1. Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education, Shandong University,Ji＇nan 250061,China;2. Electric Power Research Institute of State Grid Jiangsu Electric Power Company, Nanjing 210103, China ; 3. XJ Group Col-poration, Xuchang 461000, Chin)

机构地区：[1]山东大学电网智能化调度与控制教育部重点实验室,山东济南250061 [2]国网江苏省电力公司电力科学研究院,江苏南京210103 [3]许继集团有限公司,河南许昌461000

出　　处：《电力自动化设备》2018年第4期75-81,共7页Electric Power Automation Equipment

基　　金：许继集团有限公司科研项目(SGTYHT/14-JS-190)~~

摘　　要：传统基于相电流突变量的故障时刻检测方法虽然简单,但因受暂态分量的影响而存在较大的检测误差。利用现有保护装置采集的电流信息,对相电流突变量进行曲线拟合,并经逆向推导求出故障时刻。对电力系统的短路暂态过程进行分析,探究相电流突变量的变化规律并推导其广义表达式。利用Prony算法对离散的相电流突变量值进行函数拟合,得到表征其函数曲线的特征参数;通过改进现有的波形相似算法,进一步从拟合函数的过零点中筛选出故障时刻。结合PSCAD仿真测试,探究故障时刻的检测精度及其影响因素,仿真结果验证了所提算法的可行性和准确性。The traditional fault instant detection method based on the phase current increment is simple, but may exist a large detection error due to the influence of transient components. So with the current information collected by existing protection devices, the phase current increment is fitted and then the fault instant is obtained by inverse deri- vation. The transient process of short circuit in power system is analyzed, the variation law of phase current increment is explored and its generalized expression is deduced. The function curve of discrete phase current increment values is fitted by Prony algorithm and its characteristic parameters are obtained. The fault instant is further selected from the zero-crossing points of the fitting curve by improved waveform similarity algorithm. Simulation test is carried out in PSCAD/EMTDC to investigate the accuracy and influence factors of the fault instant detection, and the simulative results verify the feasibility and accuracy of the proposed algorithm.

关 键 词：故障时刻 相电流突变量 PRONY算法 曲线拟合 检测误差 电力系统 继电保护 

分 类 号：TM77[电气工程—电力系统及自动化]