并补装置差压保护误动原因分析及解决方案  

Mal-operation Reason Analysis and Solution for Differential Voltage Protection of Shunt Capacitors

作　　者：林国松[1] 李喆[2] LIN Guo-song;LI Zhe(Southwest Jiaotong University,Chengdu,Siehuan 610031,China;Shuo-Huang Railway Development Co.Ltd,Suning,Hebei 062350,China)

机构地区：[1]西南交通大学,成都610031 [2]朔黄铁路发展有限责任公司,肃宁062350

出　　处：《铁道工程学报》2018年第11期77-81,共5页Journal of Railway Engineering Society

基　　金：中国铁路总公司研究开发计划项目(2016J010-A);国家留学基金委资助项目(201607005128

摘　　要：研究目的:并联电容补偿装置是电气化铁路供电系统的重要设备,保护装置配置过电流、谐波过电流、差流、差压等保护。当和谐型机车通过陇海线一些供电臂的时候,频繁发生并补差压保护误动作现象。结合现场负荷为交-直-交机车的实际情况,本文通过对某所差压保护故障波形的分析,查找保护装置误动作的原因,并寻求相应的解决方案。研究结论:(1)差压保护误动作的根本原因是频率混叠对傅立叶算法的影响,导致计算差压偏大从而引起保护误动;(2)将原来的20点/周波采样运算频率改为100点/周波,消除了频率混叠对傅立叶算法的影响;(3)修改后的程序投人现场运行后,不再出现差压保护误动情况;(4)在电气化铁路供电系统领域,本文提出的分析方法和解决方案对含高次谐波的电气量分析和应用具有参考价值。Research purposes:Shunt capacitors are the important device of power system in electrified railway.The relay for shunt capacitors is equipped with over-current,harmonic over -current,difference current,differential voltage protections,etc.When HXD locomotive went through some power supply arms on Long-Hal line,mal-operation of differential voltage protection for shunt capacitors occurred frequently.According to load characteristic of AC-DC-AC locomotive and actual situation on site,the fault wave analyzed,the reason of real-operation is found,and the of differential voltage protection in a traction substation is corresponding solution is got. Research conclusions :(1)The mal-operation reason of differential voltage protection is caused by Fourier transform which is influenced by frequency abasing.The influence of frequency aliasing results in the amplification of differential voltage value and mal-operation of differential voltage protection.(2)By altering the sampling frequency from 20 points per period to 100 points per period,the influence of frequency aliasing on Fourier transform is eliminated. (3)There have been no longer mal-operations of differential voltage protection,ever since the revised program of protection came into use.(4)In the area of power supply system of electrified railway,this analytical method and solution have important reference value in analysis and application of electrical quantities with higher harmonics.

关 键 词：电气化铁路 并联电容补偿装置 差压保护 傅立叶变换 频率混叠 

分 类 号：TM922.3[电气工程—电力电子与电力传动]