摘要
电力系统绝缘配合标准IEC 60071—2(转换为国标GB/T311.2)中,没有明确接地故障因数k对应的故障形式,使得标准难以理解。该论文明确了k对应的故障形式,通过严格的理论分析、并利用等高线讨论了故障电阻对k曲线的影响。通过分析实际元件和系统,将k曲线的纵坐标R0/X1(R0,零序电阻;X1,正序电抗)、横坐标X0/X1(X0,零序电抗)上限由原来的8扩展到20,将参变量R1/X1(R1,正序电阻)由2扩展到10,并用等高线法绘制了准确k曲线,便于理解标准和工程参考。在此基础上,澄清了术语"中性点直接接地系统"和"有效接地系统"的区别,建议通过k值而不是R0/X1和X0/X1来定义"有效接地系统",由此认为我国通常的低电阻接地配电网为非有效接地系统。
The insulation co-ordination standard of IEC 60071—2,which has been adopted as a Chinese standard,does not explicitly state the fault types on which the earth fault factor k is based.This makes the standard difficult to understand.In this paper the fault types are defined.The effect of the fault resistance on k curves are discussed by employing strict theoretical analysis and contour lines.After real components and systems have been investigated,the upper limit of the vertical axis variable R0/X1(R0 is the zero sequence resistance,and X1 is the positive sequence reactance)and horizontal axis variable X0/X1(X0 is the zero sequence reactance)is extended for k curves from original 8 to 20,and the parameter R1/X1(R1 is the positive sequence resistance)is extended from 2 to 10.k curves are accurately replotted in the form of contour lines,and this makes the curves easy to understand or refer to.Based on the above discussions,the difference between terms"solidly grounded neutral system"and"effectively grounded system"is clarified.It is suggested that"effectively grounded system"should be defined with k rather than R0/X1 and X0/X1,based on which it is concluded that the common low impedance-earthed distribution systems in China are non-effectively grounded systems.
作者
李剑薇
李云阁
朱浩男
王敏
郑庆浩
LI Jianwei;LI Yunge;ZHU Haonan;WANG Min;ZHENG Qinghao(Department of Electronic&Electrical Engineering,Bath University,Bath BA27AY,UK;Electric Power Research Institute of State Grid Shaanxi Electric Power Company,Xi’an 710100,Shaanxi,China;School of Electrical and Control Engineering,Xi’an University of Science and Technology,Xi’an 710054,Shaanxi,China;Economic Research Institute of State Grid Shaanxi Electric Power Company,Xi’an 710075,Shaanxi,China;State Grid Xi’an Power Supply Company,State Grid Shaanxi Electric Power Company,Xi’an 710032,Shaanxi,China)
出处
《电网与清洁能源》
2020年第12期1-8,共8页
Power System and Clean Energy
基金
国家自然科学基金项目(U1766208)。
关键词
接地故障因数
单相接地故障
两相短路接地故障
中性点直接接地系统
有效接地系统
earth fault factor
single line-to-ground fault
double line-to-ground fault
solidly grounded neutral system
effectively grounded system
