小电流接地系统中性点接地方式比较及接地变保护整定计算分析

Comparison of Neutral Grounding Modes in Small Current Grounding System and Analysis of Grounding Transformer Protection Setting Calculation

目前在全网范围内对小电流接地系统中性点接地方式进行改造,改造方式以新建、改造非城区变电站采用消弧线圈并小电阻接地方式为主,城区全电缆出线的变电站采用小电阻方式。改造完成后,10 kV中性点接地方式将只存在两个形式:中性点接地线路当中植入小电阻;将消弧线圈和小电阻并联线路植入到中性点接地线路当中。

At present,the neutral point grounding mode of the small current grounding system is reformed in the whole network.The transformation mode includes the arc suppression coil and small resistance grounding mode in the town area,and the low resistance mode is adopted for the substation with full cable outlet in the urban area.After the transformation,there will be only two forms of 10 kV neutral grounding mode:first,small resistance is implanted into the neutral grounding line;second,arc suppression coil and parallel line with small resistance are implanted into the neutral grounding line.