基于RTDS的供电系统单相馈线零模电流接地故障特性分析

Analysis of zero-mode current grounding fault characteristics of single-phase feeder in power supply system based on RTDS

为了深入分析供电系统发生单相接地故障情况下的时域特征与故障位置、接地电阻、故障线路长度之间的关系,构建基于RTDS的供电系统仿真模型,并展开仿真分析。研究结果表明:当故障点和母线之间的距离越大时,故障线路受到的暂态零模电流影响也更弱,将形成更小的自由震荡频率,从而削弱了暂态变化特征;当故障点和母线间距增大后,使健全线路受到暂态零模电流冲击作用降低。在较低的接地电阻情况下,在零值附件形成的暂态零模电流表现为显著周期振荡模式的衰减过程。随着暂态零模电流冲击值的降低,产生的暂态过程也越弱,故障线路零模电流发生更显著变化,健全线路则处于一个稳定状态。当故障线路的长度增大后,对暂态零模电流产生的影响也降低。

In order to deeply analyze the relationship between the time-domain characteristics of the power supply system in the case of single-phase grounding fault and the fault location, grounding resistance and fault line length, a power supply system simulation model based on RTDS was constructed and the simulation analysis was carried out.The results show that the larger the distance between the fault point and the bus, the weaker the influence of the transient zero-mode current on the fault line, and the smaller the free oscillation frequency will be.When the distance between the fault point and the bus increases, the transient zero-mode current impact on the sound line decreases.In the case of low grounding resistance, the transient zero-mode current formed in the zero-value attachment shows the attenuation process of significant periodic oscillation mode.With the decrease of the transient zero-mode current impulse value, the transient process becomes weaker, the zero-mode current of the fault circuit changes significantly, and the sound circuit is in a stable state.When the length of the fault line increases, the effect on the transient zero-mode current also decreases.