110 kV GIS同频同相交流耐压试验中三工位隔离开关内部电场分布特性

同频同相交流耐压试验技术因无须GIS母线全停，可以显著地提高供电可靠性，近年来在GIS改扩建工程中得到了广泛应用。目前110 kV GIS普遍采用三相共筒式结构，同频试验过程中三工位隔离开关断口或相间可能会存在击穿的风险，需要对三工位内部电场分布进行分析。采用有限元法对同频同相试验技术在110 kV三相共筒式GIS耐压试验中三工位隔离开关内部电场进行了分析，仿真中结合实际试验过程中的加压要求和加压过程所对应的边界条件，获得了试验中三工位隔离开关内部不同位置的电场分布特性，得到了不同加压方式电场较大的位置，在此基础上，对内部结构参数对电场的影响规律进行了分析，研究结果可以为同频同相试验技术在110 kV GIS耐压实验中的应用提供了理论和数据支撑。

Distribution of Electric Field in Three-Station Disconnecting Switch in Same Frequency and Phase AC Withstand Voltage Test of 110 kV GIS

The same frequency and phase AC withstand voltage test technology without GIS bus stop can enhance the power supply reliability. Therefore, it has been widely used in the GIS reconstruction and extension project in recent years. The three-phase cylindrical structure is generally adopted in 110 kV GIS devices. During the same frequency and phase test, there may be breakdown risk in the break-down or inter-phase of the three-station disconnecting switch. Hence, it is necessary to analyze the electric field distribution inside the three-station disconnecting switch. In this paper, the finite element method is used to analyze the internal electric field of three-station disconnecting switch in the 110 kV three-phase cylindrical structure during the GIS withstand voltage test. According to the voltage requirement and the corresponding boundary conditions during the actual test, the electric field distribution characteristics at different positions inside the three-station disconnecting switch are demonstrate in the simulation results. The positions with maximum values of electric field under different applying voltage modes are obtained. Furthermore, the influence of internal structure parameters of the three-station disconnecting switch on the distribution of electric field was analyzed. The presented results can provide theoretical and data support for the application of the same frequency phase withstand voltage test technology in 110 kV GIS devices.