Full Wave Simulation of Transient Electromagnetic Field During Switching Operation of GIS power Substation

With the rapid development of intelligent power substations, more and more secondary devices are installed nearby the high-voltage disconnector. The switch operations in gas-insulated switchgear (GIS) substation will generate very fast transient overvoltage (VFTO). The leakage of VFTO from the GIS pipeline shell will cause strong transient electromagnetic field nearby the GIS shell. The transient electromagnetic field may lead to maloperation, failure or even damage of the aforementioned secondary equipment. At present, there are many researches on the conducted electromagnetic disturbance induced on the ports of secondary equipment. However, the researches on the transient electromagnetic disturbance are few, especially in term of 3D full-wave simulation. In this paper, a 3D full wave model is built in the electromagnetic field software CST to simulate the very fast transient electromagnetic field resulted from the switching operation of GIS power substation. The steep wave power supply is used as the excitation source, and the time-varying resistance is used to simulate the switch operation process. The characteristics of spatial electromagnetic field disturbance, including the dominant frequencies, the peak, and the rise and duration time. It is shown that the spatial field is a damped oscillatory wave with oscillation frequency between 0.85 - 47.8 MHz and magnitude up to 706.9A/m. The effect of GIS pipeline length on the field characteristics is also investigated. The results are helpful for determining the immunity test level of typical secondary equipment against the transient spatial electromagnetic disturbance.