摘要
电力电缆多直埋敷设于地下,发生故障后需要精确地定位电缆故障点。因此如何快速且精确地定位电缆故障点是直流配电网故障测距的关键性问题。当故障发生后,通过并联双晶闸管辅助电路,能够建立直流侧故障极边界电容电压完整暂态放电过程,利用直流侧边界电容动态响应的暂态特征,提出一种基于时间常数的故障测距方案。该方案通过离线建立时间常数与故障距离拟合曲线,利用τ-x或Δτ_e-x拟合曲线在线实现故障测距。最后在PSCAD/EMTDC中进行仿真验证,定位误差精度达到1%以内,符合工程要求。该方案不受故障距离和过渡电阻的影响,满足直流配电网对故障定位速动性和精确性的要求。
The power cable is buried in the ground.After the fault occurs,how to locate the cable fault point quickly and accurately is a key issue in the fault location of the DC distribution network.After the fault occurs,through parallel double thyristor auxiliary circuit,a complete transient discharge process of DC fault pole boundary capacitor voltage can be established.Based on the transient characteristics of the DC side boundary capacitor dynamic response,a fault location scheme based on time constant was proposed.The scheme establishes a time constant and a fault distance fitting curve off-line,and usesτ-x orΔτ_e-x fitting curve to realize fault ranging on-line.Finally,the simulation is verified in PSCAD/EMTDC,and the positioning error accuracy is less than 1%,which meets the engineering requirements.The solution is not affected by the fault distance and transition resistance,and meets the requirements of the DC distribution network for fault location speed and accuracy.
作者
高超
薛毓强
林雨丰
GAO Chao;XUE Yuqiang;LIN Yufeng(College of Electrical Engineering and Automation,Fuzhou University,Fuzhou 350108,China)
出处
《电器与能效管理技术》
2019年第22期68-76,共9页
Electrical & Energy Management Technology
关键词
直流配电网
边界电容
时间常数
故障定位
DC distribution network
boundary capacitance
time constant
fault location
