环形金属回流极对接地装置暂态特性的影响

Influence of the return ring electrode on the transient characteristic of grounding devices

针对接地装置冲击暂态特性进行试验是最直接和最有效的研究方法。冲击电流在流经接地装置后,应使其通过阻抗较低的回流路径返回冲击电流发生器。该文基于CDEGS软件,计算分析了环形金属作为回流极时对接地装置地电位升的影响;同时,对金属回流环作为参考极时的补偿效果进行了讨论;进而还分析并指出了使用金属回流环时存在参考点的充要条件。研究表明:环形金属回流极拉低了接地装置电位;金属圆环作为回流极时,空间内是否存在参考极与土壤电阻率密切相关。

Tests of the transient characteristics of grounding devices is the most direct,effective method to evaluate such devices.In these tests,the impulse current backflow path should have low impedance.This study analyzes the effect of the return ring electrode on the impulse impedance of the grounding device using CDEGS to calculate the influence of the return ring electrode.The compensation effect of the ring electrode as the reference pole is also analyzed.The sufficient and necessary condition is given for the existence of a reference pole when the return ring electrode is used with this condition strongly related to the soil resistivity.The analysis shows that the return ring lowers the potential rise in the grounding device.