目前,我国已有不少配电网中性点采用了经电阻接地的运行方式。安装中性点接地电阻柜后,当发生非金属性接地时,受接地点电阻的影响,流过接地点和中性点的 电流比金属性接地时有显著降低,
Currently, many distribution networks in China have adopted the resistive grounding operation mode. After installing the neutral grounding resistor cabinet, when a non-metallic grounding occurs, the current flowing through the grounding point and the neutral point significantly decreases compared to metallic grounding, due to the influence of the grounding point resistance,
同时,健全相电压上升也显著降低,零序电压值约为单相金属性接地的一半。由此可见,采用中性点经电阻接地,可降低单相接地 时的暂态过电压、消除弧光接地过电压和某些谐振过电压,并能采用简单的继电保护装置迅速选择故障线路,切除故障点。
Meanwhile, the phase-to-ground voltage rise is also significantly reduced, with the zero-sequence voltage approximately half that of a single-phase metallic ground fault. Thus, employing a neutral point resistance grounding system can mitigate transient overvoltages during single-phase faults, eliminate arc grounding overvoltages and certain resonant overvoltages, and enable the use of simple relay protection devices to quickly identify faulted lines and isolate the fault point.