城市地下变电所环网接地装置的设计和计算

Design and Calculation of Earthing Device for Loop Network at Urban Underground Substation

大楼地下 35kV及以上变电所的环网接地装置 ,除利用大楼基础钢筋作自然接地体外 ,还须敷设人工接地网。其环网接地装置必须结合建筑物特点进行设计 ,接地电阻可用简化公式估算。环网接地装置的接地电阻值主要决定于环网的面积 ,在网内增加水平接地体 ,尤其是增加垂直接地体效果不大。

The loop network earthing device for 35 kV and above substations under the buildings shall need lay the manual grounding network besides taking the foundation reinforcement of the buildings as its natural earthing body.So the loop network-earthing device must be designed in combination with building characters and the earthing resistance can be estimated with a simplified formula.The earthing resistance is mainly dependent on the area of the loop network,so addition of the horizontal earthing body,especially the vertical body in the network will have no significant result. [