用于环保型C-GIS的氮气及干燥空气正极性雷电冲击特性研究

Study on Positive Lightning Impulse Characteristics of Nitrogen and Dry Air for Eco-friendly C-GIS

采用氮气或干燥空气替代SF6作为绝缘介质是目前环保型柜式气体绝缘金属封闭开关设备(C-GIS)的研究热点。要保证气箱内部结构紧凑、小型化的特征,需要充分掌握气体介质的绝缘特性,寻找电场均匀度对气体高压击穿特性的影响规律。文中研究了在0.10、0.15 MPa压力下,不同电极形式、电极间隙下的两种绝缘气体的正极性雷电冲击耐压特性。数据对比表明:干燥空气相比氮气具有更高的正极性雷电冲击电压击穿特性。同时总结了最大击穿场强E_(max)与电场均匀度刀之间的关系,得到C-GIS绝缘结构设计方面的关键判据。

Using nitrogen and dry air to replace SF6 as the insulation material for eco-friendly cubic gas insulated switchgear(C-GIS) is very popular nowadays. To ensure the characteristics of compact structure and small size, engineers have to fully understand the insulation characteristics of the substitute gases. This article studies the fundamental properties of dry air and N2 as the insulation medium from the respects of different electrode forms or electrodes gaps at 0.1 MPa and 0.15 MPa gas pressures. Comparison of experimental data indicates that the insulation withstand level of dry air is higher than Nitrogen for the positive lightning voltage. Simultaneously, we conclude the relation between the Emax(maximum electric field strength) and the η(electric field utilization) as the critical criterion of the C-GIS insulation structure designing.