基于IEEE Std 80与GB/T 50065的变电站接地差异分析

Difference Analysis of Substation Grounding Based on IEEE Std 80 and GB/T 50065

摘要:

随着中国电力设计企业在海外变电工程业务的逐年增多,接地网设计标准的差异在国际电力工程建设的执行过程中成为日益凸显的问题。在分析比较了IEEE std 80和GB/T 50065的基础上,给出了两本规范在接地导体的选择、接地判据侧重点以及分流系数计算方法上存在的异同点。同时详细分析了接地导体截面选择、接地电阻、接触电势、跨步电压等在计算结果上存在差异的内部原因。以海外某变电站接地网设计为例,详细比较了以上差异,为国内电力工程师在进行国外变电站接地网设计时提供标准选择方法。

Abstract:

With the development of overseas power transformation projects by Chinese power design companies year after year,the differences in design standards for grounding grids have become increasingly prominent issues in the implementation of international power project construction. Based on the analysis of IEEE std 80 and GB/T 50065,the similarities and differences between the two specifications in the selection of grounding conductors,the grounding criteria and the calculation method of shunt coefficients are presented. At the same time,the internal causes of the differences in the calculation results such as cross-section selection,grounding resistance,touch potential difference and step potential difference of the grounding conductor are analyzed in detail. Taking the design of grounding grid in a substation abroad for example,the above differences are compared in detail to provide a standard selection method for power engineers when designing a grounding grid for a foreign substation.