谐振接地系统单相接地故障暂态仿真与分析

Single Phase Grounding Fault Transient Simulation and Analysis of Resonant Grounding System

在谐振接地系统时域、频域特征分析的基础上,通过Matlab软件建立以分布参数为基础的高精度谐振接地系统单相接地故障仿真模型,分析了几种极端故障情况下的线路零序电流波形的特征。通过分析可得:谐振接地系统单相故障暂态接地电流中含有暂态电感电流与电容电流,其比例随故障时刻的不同而变化;在选定频带内,故障线路和非故障线路暂态零序电流极性相反;故障初相角为零附近(0～30°)经小电阻接地故障情况下,故障线路零序电流出现倒相,且倒相程度随故障初相角的变化而不同;在大电阻接地故障的情况下,故障与非故障线路零序电流在稳态时出现一定的相位移。

On the basis of resonant grounding system time domain and frequency domain features analysis, this paper established high accuracy resonant grounding system single phase grounding fault simulation model with distributed parameters as basis via Matlab software and analyzed charac- teristics of line zero-sequence current waves under some kinds of extreme fault conditions. Analysis showed that single phase fault transient ground cur- rent of resonant grounding system contained transient inductor current and capacitor current, whose proportion varied with fault time. Within the selected fi＇equency band, the polarity of transient zero-sequence current in the fault line was opposite to that of non-fault line. When the early phase angle is near zero（0--30°）, in the case of low resistance grounding fault, fault line zero-sequence current appeared in reversed phase, changing differently following fault early angle changes. In the case of large resistance grounding fault, fault and non-fault line zero-sequence current would have a phase shift in steady-state.