高速铁路运行牵引变电站接地安全测量计算分析

高速铁路牵引变电站投运之后其接地网与综合接地系统以及电力系统进线避雷线连接,变电站接地拓扑结构发生巨大变化,此时对牵引变电站的接地安全校验不应仅局限于变电站本身。为研究运行牵引变电站接地安全性,现场测试运行牵引变电站分流特性和站址土壤结构,并运用数值仿真计算手段,结合现场实测数据和计算结果对运行牵引变电站开展接地安全分析,同时对比分析牵引变电站接地网连接和不连接进线避雷线时的测量和计算结果。结果表明:高速铁路牵引变电站接地安全校验应结合工程具体情况整体考虑,避免只简单注重接地阻抗值是否低于0.5Ω;牵引变电站接地网连接电力系统电源进线避雷线后,接触电压、跨步电压和地电位升均有较大幅度的下降。研究成果已在深茂高铁沿线牵引变电站接地安全校验中成功应用,通车后牵引变电站安全稳定运行。

Grounding Safety Measurement,Calculation and Analysis of High-speed Railway Traction Substation in Operation

After the high-speed railway traction substation is put into operation, its grounding grid is connected with the integrated grounding system and the incoming lightning arrester of the power system. Great changes have taken place in grounding topology of the traction substation and the grounding safety verification of the traction substation should not be limited to the substation itself. In order to study the grounding safety of the traction substation in operation, shunt characteristics and soil structure are tested on site. Numerical simulation method is also used to analyze grounding safety of the traction substation based on field measured data and calculation results. Meanwhile, the measurement and calculation results of grounding grid connection and disconnection of incoming lightning arrester in traction substation are compared and analyzed. The results of measurement and calculation show that: The grounding safety checking of high-speed railway traction substation should be considered as a whole according to the specific conditions of the project, so as to avoid focusing only on whether the grounding impedance value is lower than 0.5 Ω. After traction substation grounding grid is connected with the incoming lightning arrester of the power system, the contact voltage, step voltage and ground potential rise of traction substation grounding grid are all reduced greatly. The research results have been successfully applied in grounding safety verification of traction substation on Shenzhen-Maoming high-speed railway, and the traction substation operates safely and steadily after the high-speed railway is opened to traffic.