500 kV GIL管廊接地系统分析

Analysis of 500 kV GIL Tube Grounding System

摘要:

气体绝缘金属封闭输电线路的接地系统对该输电方式的稳定可靠运行至关重要。基于CDEGS仿真软件对某实际GIL综合管廊工程的接地系统进行了研究,建立了GIL综合管廊接地系统模型,对接地系统的接地电阻、跨步电压、接触电压以及地电位升等电气特性参量进行计算分析,研究了接地网的深度、混凝土电阻率、入地点的个数、钢筋主支架等因素对GIL管廊电气特性的影响规律,提出了较为优化的接地系统。结果表明,混凝土结构钢筋作为自然接地体对GIL电气特性的影响最大,入地点个数对GIL电气特性的影响最小。优化的接地系统为GIL综合管廊的建设和运维提供了依据。

Abstract:

The grounding system of gas insulated metal enclosed transmission line ( shorted for GIL) is very important for the stable and reliable operation of the transmission mode． The grounding system of an actual 500 kV GIL project is studied based on CDEGS． Its grounding system model is established，and the electrical characteristic parameters such as earth resistance，step voltage，touch voltage and earth potential rise are calculated and analyzed． The influence rules of the depth of grounding grid， the concrete resistivity，the number of earth points and the main structure steel on the electrical characteristics of GIL grounding system are studied． The results show that the reinforced concrete structure as a natural grounding body has the greatest influence on the electrical characteristics of GIL，and the number of earth points has the least impact on the electrical characteristics of GIL． The optimized grounding system of GIL provides a basis for the construction and operation of GIL utility tunnel