分层土壤短距离放线下接地电阻测试方法研究

当土壤不均匀，如土壤为双层甚至三层时，采用传统补偿法测量接地电阻往往会带来较大测量误差。研究提出了短距离放线方式下接地电阻测试方法。分析了工频接地电阻与电流注入点的位置关系，研究了不同电流注入点对接地电阻测量偏差的影响规律，验证了短电流极引线法在工频接地阻抗测试中的可行性。针对不同的土壤结构，研究了电流引线布线长度对电压补偿点位置的影响。提出不同土壤结构下电流引线长度的选取规律，实现了短电流引线下接地阻抗的准确测量。

Measuring Method of Grounding Resistance under Short Distance Laying-out in Layered Soil

When the soil is not uniform，such as two-layer or even three-layer soil， the traditional compensation method can causes a large error in grounding resistance measurement. Therefore， this paper proposes a measuring method of the grounding resistance under short distance laying-out mode， analyzes the position relationship between the power frequency grounding resistance and the current injection point， investigates the influence law of different current injection points on the grounding resistance measurement deviation， and verifies the feasibility of short current electrode lead method in the power frequency grounding impedance measurement. Moreover， according to different soil structures， the influence of current lead length on voltage compensation point location is analyzed， and the selection law of the current lead length in different soil structures are put forward， realizing the accurate measurement of the grounding impedance with short current lead.