800 kV三相分箱GIS变电站外壳感应电压及环流分析

Analysis of Induced Voltage and Circulating Current in 800 kV Three-Phase Sub-Box GIS Substation

气体绝缘组合电器(GIS)是高压电网建设的关键设备,随着电网规模的日益增大以及大量自动化设备在GIS变电站中的广泛使用,GIS变电站的可靠性指标要求越来越高。为了研究GIS变电站的外壳感应电压和环流分布情况,基于实际变电站的电气主接线及设备的各项参数,使用电磁暂态仿真软件EMTP搭建变电站级800 k V三相分箱GIS变电站的电路仿真模型,探讨了GIS变电站稳态运行、外部单相故障及外部三相故障时GIS变电站内部各关键点的感应电压和环流分布,分析了变电站不同运行方式对稳态感应电压及环流大小的影响。研究表明,接地点的安装应在主变分支和负载分支较为密集,从而起到减小外壳感应电压和环流的作用。研究对实际GIS变电站感应电压和环流的计算以及接地系统的校验工作有一定的指导意义。

Gas insulated switchgear( GIS) is the key equipment for the construction of high-voltage power grids. With the increasing scale of the power grid and the widespread use of a large number of automation equipment in GIS substations,the reliability requirements of GIS substations are becoming higher and higher. In order to study the distribution law of induced voltage and circulating current of GIS substation,based on the electrical main wiring of the actual substation and various parameters of the equipment,electromagnetic simulation software EMTP is used to build the simulation model of 800 kV three-phase sub-box GIS substation. It is discussed induced voltage and circulating current’s distribution of each key point in the GIS substation during steady-state,external single-phase grounding fault and external three-phase grounding fault. It is also analyzed the effects of different operation modes of the substation on induced voltage and circulating current under steady-state. The research shows that the installation of the grounding point should be relatively dense on transformer branch and load branch,thereby reducing induced voltage and circulating current. The research has certain guiding significance to the calculation of induced voltage and circulating current of the actual GIS substation and the verification of the grounding system.