接地系统地面高阻层的特性  

Characteristics of Surface High-resistance Coverings in Grounding System

作　　者：张云 张波[2] 陈伟军 庄池杰[2] 

机构地区：[1]广东电网公司惠州供电局,惠州516001 [2]清华大学电机工程与应用电子技术系,北京100084

出　　处：《高电压技术》2015年第5期1582-1588,共7页High Voltage Engineering

基　　金：国家自然科学基金(51277107)~~

摘　　要：为了获得地表高阻层的电阻率、厚度等对接地网各项参数的影响，以某50m×50m接地网为例，基于电磁场数值计算手段，搭建高阻层计算模型，开展仿真研究工作，进一步总结高阻层使用时需要注意的问题，提出高阻层的使用方法，以便指导工程实际。研究表明：由于高阻层的电阻率和厚度对接地电阻、地表电位分布、接触电势差、跨步电势差等影响很小，但高阻层可以明显提高人体的耐受限值，因此高阻层是提高接地网安全性能的非常有效的措施。由于人体的耐受限值随高阻层厚度的增加存在饱和趋势，建议高阻层厚度在0．1～0．2m即可。为了保证高阻层的使用效果，在实际工程中，最好将接地网埋设在原土壤下0．8m处，再在土壤表面增设高阻层。In order to obtain the influence of the resistivity and thickness of high-resistance covering on the parameters of grounding grid, we set up a model of the high-resistance layer by using the electromagnetic numerical method, simulated the performance of a 50 m×50 m grounding grid with high-resistance covering, and summarized the problems that need to be considered when using the surface high-resistance coverings. Then we put forward the proposals on how to use the surface high-resistance coverings in order to guide the engineering practice. The investigation results based on numerical simulation show that the influences of the surface high-resistance coverings on the grounding resistance, ground potential rise, touch potential difference, and step potential difference are very small, while the surface high-resistance coverings can improve the tolerance limits of the touch potential difference and the step potential difference greatly. Thus, covering the earth surface with high-resistance layer is a very effective measure to improve the safety performance of the groun- ding grid. Due to the saturation trend of the tolerance limits with the increasing of the high-resistance coverings＇ thickness, it is suggested that the enough thickness of high resistivity layer should be 0.1-0.2 m. In order to guarantee the effect of the high-resistance coverings, the grounding grid should be buried in soil with a depth of 0.8 m, and then the high-resistance covering should be added directly on the soil＇s surface in actual project.

关 键 词：变电站 接地系统 地表高阻层 跨步电位差 接触电位差 接地电阻 

分 类 号：TM862[电气工程—高电压与绝缘技术]