分层土壤中典型特高压杆塔基础接地计算的建模与分析  

Modeling and Analysis for Calculation of Typical UHV Tower Foundation Grounding Resistance in Layered Soils

作　　者：刘铜锤 潘文霞[1] 王兵[2] 戴敏[3] 黄涛[4] 

机构地区：[1]河海大学能源与电气学院,江苏南京210098 [2]国网江西省电力公司,江西南昌330000 [3]中国电力科学研究院,湖北武汉430074 [4]江苏方天电力技术有限公司,江苏南京211102

出　　处：《中国电力》2015年第11期82-87,共6页Electric Power

摘　　要：由于特高压杆塔基础尺寸大、钢筋多,在水平分层土壤条件下,杆塔基础可能穿入下层土壤,以往的简化方法计算特高压杆塔基础的接地电阻会产生较大的误差,难免造成不经济的设计。针对该问题,依据电磁场基本原理,同时考虑土壤水平分层土壤结构和杆塔基础混凝土层穿入下层情况,采用矩量法对静电场积分方程进行离散,并基于C++编程进行数值求解。文中通过典型特高压杆塔基础算例的接地电阻计算,说明了该方法的有效性和正确性。还分析了典型特高压杆塔基础接地电阻与水平双层土壤模型参数的关系,说明上层土壤厚度逐渐增大是影响典型特高压杆塔基础接地电阻的主要决定因素,同时说明当上层土壤厚度较浅时,降低下层土壤电阻率对减小杆塔基础接地电阻效果明显,准确估计下层土壤电阻率对接地计算有重要影响。Due to its large dimension and numerous vertical rods, the UHV tower foundation may penetrate a second soil layer of the horizontal layered soils. As a result, the conventional simplified method for computation of UHV tower foundation grounding resistance may cause large deviation, which can bring out uneconomic design. In order to solve this problem, the integral equation for electrostatic field is diseretized in this paper carries by using MOM, which is programmed by C＋＋ to obtain the numerical results. The grounding resistauce is calculated with this algorithm for a typical UHV tower foundation, which proves the algorithm＇ s validation. An analysis is carried out on the relationship between the grounding resistance of UHV tower foundation and the modeling parameters of double-layer soil, which indicates that the thickness of the upper layer is the decisive factor for the grounding resistance of a typical UHV tower foundation, and when the upper soil is small in thickness, lowering the specific resistance of the lower layer is obviously effective for reducing the grounding resistance of tower foundation. It is therefore very important to accurately estimate the subsoil resistivity for the grounding calculation.

关 键 词：杆塔基础 矩量法 灌注桩 双层土壤 接地电阻 

分 类 号：TM753[电气工程—电力系统及自动化] TM862