降阻剂对垂直型直流接地极电气性能参数影响分析

Analysis of Influence of Resistance Reducing Material on Electrical Performance Parameters of Vertical DC Ground Electrode

交流接地系统一般只会流过短时故障电流,而直流接地极在单极运行方式下,需要长时间通过几千安培的工作电流,因此对接地极各项电气性能参数(接地电阻、地电位升、跨步电压、电流溢流密度等)的要求更为苛刻,从而对极址选择和极体设计的要求也更高,有鉴于此,结合四川省兴文县万寿极址的土壤模型,采用数值分析的方法,计算分析了不同长度和根数的垂直接地体敷设降阻剂后对直流接地极各项电气性能参数的影响。结果表明,在下层土壤电阻率较高的地区,单纯采用垂直接地体对接地极的影响不大,而在此基础上使用降阻剂后,接地极的各项电气性能参数能得到有效改善。

AC grounding system generally will only through the transient fault current, but DC grounding electrodes operated in monopole operation mode will withstand the working current ot thou- sands amperes for a long time, so it have a more strict requirements on Electrical performance parameters （such as grounding impedance, grounding grid potential rise, step voltage, current overflow density, etc.） and correspondingly the site selection and design requirements are higher. Accordingly, further analysis is needed. The analysis is simulative and is based on the soil model of Xingwen County of SiChuan Province, researching the different length and number of vertical grounding electrodes to the influence of DC grounding electrode＇ s electrical performance parameters. It is shown that in the high soil resistivity areas, the vertical grounding electrodes has a little effect on the electrical performance parameters, but on this basis, due to the application of resistance reducing material, all the electrical performance parameters can be effectively improved.