土壤特性对变电站接地网特性参数影响的数值分析  

Numerical Analysis of Influence of Soil Characteristics on Characteristic Parameters of Substation Grounding Grid

作　　者：李谦[1] 文习山[2] 肖磊石[1] 

机构地区：[1]广东电网公司电力科学研究院,广州510080 [2]武汉大学电气工程学院,武汉430072

出　　处：《高电压技术》2013年第11期2656-2663,共8页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2009CB724500)~~

摘　　要：为了了解土壤特性对接地网特性参数(接地阻抗、地线分流、地网电位升高、场区压差、跨步电压和接触电压)的影响规律,结合具体的工程案例,采用数值仿真方法,分析接地网特性参数与土壤分层结构特性之间的相关性。结果表明,站址土壤电阻率不同时,接地网特性参数在变电站发生单相接地短路故障时具有不同的表现行为,接地网特性参数是分层结构土壤电阻率、接地网结构和形状以及入地故障电流水平等几个因素协同作用的结果。高土壤电阻率条件不利于散流,地网电位升高较高,但整体压差较小,跨步电压和接触电压分布较为均衡。低分层土壤电阻率条件下,地网电位升高很低,但场区压差较大,高水平跨步电压和接触电压可能出现在接地故障点且超过安全限值,在设计时应注意均压措施的完善。In order to learn the influences of soil characteristics on characteristic parameters of grounding grid （ such as grounding impedance, shunt of ground wires, grounding grid potential rise, grounding grid potential rise difference, step voltage, and touch voltage, etc. ）, the relationship between the characteristic parameters and the characteristics of layered soil is analyzed. The analysis is simulative and is based on data from practical cases. It is shown that the characteristic parameters of grounding grid under single-phase grounding fault are different in substations with different soil resistivity, and that these characteristic parameters result from the synergy of the resistivity of layered soil, the structure and shape of grounding grid, and the fault current into the earth. High soil resistivity is unfavorable for current diffusion and causes higher potential rise, but it results in overall lower potential difference and relatively more uniform distribution of step voltage and touch voltage. In contrast, low soil resistivity is favorable for current diffusion and makes potential rise much lower but it induces higher potential difference and may cause the step voltage and touch voltage around the default point, which are high enough to exceed safety limits. Therefore, voltage equalizing should be paid attention to in future dcsigns.

关 键 词：土壤特性 接地网 特性参数 设计 安全性状态评价 分层 

分 类 号：TM862[电气工程—高电压与绝缘技术]