110 kV三相共筒式GIS同频同相交流耐压试验中隔离开关断口击穿特性仿真分析

同频同相交流耐压试验技术因无需母线全停，现已在220 kV GIS设备检修或扩建后的绝缘性能试验中得到了广泛应用。然而，110 kV变电站普遍采用三相共筒式GIS设备，由于相间紧凑布置，在对三工位隔离开关进行耐压试验时，隔离开关断口击穿风险较大，这将给系统供电可靠性带来极大影响。使用EMTP-ATP仿真软件搭建了同频同相交流耐压试验中110 kV GIS设备隔离断口击穿仿真模型，获得了同相击穿和异相击穿的故障电压及电流特性，分析了加装保护电阻对击穿特性的影响规律，给出了击穿特性抑制措施建议，为同频同相技术在110 kV GIS设备交流耐压试验中的应用提供了指导。

Simulation Analysis of Breakdown Characteristics in Isolation Switch Fracture in Same Frequency and Phase AC Withstand Voltage Test of 110 kV Three-Phase Cylindrical GIS

The same frequency and phase AC withstand voltage test technology has been widely used in the insulation performance test of inspection or expansion in 220kV Gas Insulated Switchgear (GIS), which can avoid stopping running grid bus of the system. However, the technology has been promoted in the withstand voltage test of GIS equipment with 110 kV voltage level. The three-phase cylindrical structure is generally adopted in 110 kV GIS devices. Due to the small inter-phase space, the switch has a higher risk of breakdown when the three-station disconnecting switch is subjected to the withstand voltage test. In this paper, the EMTP-ATP simulation software is used to construct the breakdown model of 110 kV GIS equipment in the same frequency and phase AC withstand voltage test. The fault voltage and current characteristics of the same phase and wrong phase is obtained. The influence of the installation protection resistances on the breakdown characteristics is analyzed, and the suggestions for suppression of the breakdown characteristics are given. This paper can provide useful references for the application of the same frequency and phase technology in the AC withstand voltage test of 110 kV GIS equipment.