一起10 kV谐振接地系统连续故障分析

Continuous Fault Analysis of A 10 kV Resonant Earthed System

单相接地故障在电网中发生故障率较高,研究单相接地故障对提升供电可靠性有重要意义。文中从母线电压的角度剖析了10 kV谐振接地系统发生单相接地故障的特点,洞悉单相接地故障的诸多原因,进而减小单相接地故障的发生率,保证电网安全稳定运行。首先,分析系统单相接地故障接地时的暂态过程,得出了暂态电流的具体数学模型;然后,对该起故障的录波波形进行分阶段定性分析,同时使用Matlab仿真验证分析的正确性,并探究了在不同接地电阻下母线电压的变化规律;最后,针对谐振接地系统提出建议以减小单相故障的影响范围,具有较高的工程应用价值。

Single-phase grounding fault has a high rate occurred in power grid,so its research is of great significance to improve the reliability of power supply.The characteristics of single-phase grounding faults in 10 kV resonant earthed systems are analyzed from the perspective of bus voltage,and several causes of single-phase grounding faults are known clearly,thereby reducing the incidence of single-phase grounding faults and ensuring the safe and stable operation of power grid.Firstly,the transient process of single-phase grounding fault is briefly analyzed,and the specific mathematical form of transient currentis obtained.Then a qualitative analysis of the recorded waveform of fault in stagesis carried out,Matlab simulation is used to verify the correctness of the analysis,and the variation rule of bus voltage under different grounding resistance is explored.Finally,several suggestions are proposed for the resonant earthed system to reduce the impact of single-phase faults.