Oil-immersed Distribution Transformer Local Discharge Detection Interference Analysis and Shielding Effectiveness of the Device

Oil-immersed distribution transformer online monitoring device (hereinafter referred to as the device) is located in the electromagnetic environment is very complex, in order to ensure the normal operation of the device, the ability of the device shielding interference electromagnetic wave is particularly important. This chapter firstly analyzes the harm degree of electromagnetic harassment generated by overvoltage on the device, as well as the propagation mechanism of high-frequency electromagnetic waves in a single-layer metal conductor; then analyzes the shielding effectiveness of different structural holes and seams, equal-area porous and equal-area porous with different spacing, and obtains the theoretical reference strategy of the porous arrangement; secondly, taking the operational overvoltage acting on the B-phase of the transformer as an example, the electric field and magnetic field changes in the transformer internally when subjected to operational overvoltage are analyzed by simulation, and the shielding ability is particularly important for the operation of the device. Secondly, the electric field and magnetic field changes when the transformer is subjected to operational overvoltage are simulated and analyzed, and the waveform characteristics of UHF signals under overvoltage are obtained; finally, the aperture models are established in various cases, and the theoretical reference strategy is verified through simulation to establish a suitable shielding shell design scheme, and the shielding effectiveness of optimized shielding shells under different materials and environments is verified in simulation.