Study on the Effect of Space Radiated Electromagnetic Interference Generated by AC Filter Busbar VFTO on Secondary System

In recent years, with the implementation of the “Dual-Carbon Strategy”, the construction scale of new energy stations has gradually increased. AC filters in new energy stations can eliminate the large amount of harmonics generated by power electronic switching devices and compensate for the large amount of reactive power consumed by them. However, the switching operation of AC filters enclosed in the GIS structure generates severe VFTO and is accompanied by strong electromagnetic interference. Current research indicates that the EMI generated by the AC filter GIS busbar charging operation is sufficient to affect the normal operation of the secondary system that monitors the operating status of the synchronous compensator. In this paper, we take the disturbed secondary equipment in the plant of synchronous compensator as the research object, and analyze the influence of spatial electromagnetic interference on it through the electromagnetic field distribution in its vicinity. In this paper, firstly, the calculation model of AC filter GIS busbar VFTO is established, and the busbar overvoltage under different closing angles and load-side residual voltages is calculated, and then the electromagnetic field around the AC filter and synchronous compensator plant is calculated under the condition of maximum overvoltage, and the degree of interference of the secondary equipment is analyzed. The results of the study show that the electromagnetic field strength of space radiation generated by the AC filter GIS busbar opening and closing is less than the standard requirements for secondary equipment to withstand electro-magnetic field, so the electromagnetic interference is not coupled to the secondary equipment of the synchronous compensator plant through space radiation.