异性导电媒质对直流接地极跨步电压分布的影响

为了研究异性导电媒质对直流接地极跨步电压分布的影响,通过CDEGS建立水平双圆环直流接地极模型,计算极址外部附近以及极址区域内存在异性导电媒质时的跨步电压分布.结果表明:当接地极极址外部附近存在一块高(低)电阻率的异性媒质时,将会使外环靠近异性媒质区域的溢流密度及跨步电压下降(升高);当极址内部的表层局部区域存在一块高(低)电阻率的异性媒质时,将会使位于异性导电媒质的环段的溢流密度下降(升高),但跨步电压却反而增加(降低);当极址内部的下层局部区域存在一块高(低)电阻率的异性媒质时,将会使位于异性导电媒质的环段的溢流密度和跨步电压同时降低(升高).研究成果可为直流输电工程中接地极设计及选址提供参考.

Research on Influence of Anisotropic Conducting Medium on Step Voltage Distribution of DC Grounding Electrode

In order to study the influence of anisotropic conductive medium on the step voltage distribution of DC grounding electrode, a horizontal double ring DC grounding electrode model is established by CDEGS, and the step voltage distribution is calculated when there is a anisotropic conductive medium near and outside the electrode site. The results show that when there is a high (low) resistivity anisotropic medium near the outside of the grounding electrode site, the step voltage distribution will be The overflow density and step voltage of the ring near the anisotropic medium decrease (increase); when there is a piece of anisotropic medium with high (low) resistivity in the local area of the surface layer inside the polar site, the overflow density of the ring section located in the anisotropic conductive medium will decrease (increase), but the step voltage will increase (decrease); When there is a high (low) resistivity anisotropic medium in the lower part of the polar site, the overflow density and step voltage of the ring segment located in the anisotropic conductive medium will decrease (increase) at the same time. The research results can provide a reference for the design and site selection of grounding electrodes in HVDC projects.