The propagation characteristics of electromagnetic wave generated from partial discharges in power transformer by FDTD simulation

The radiation and propagation of electromagnetic (EM) waves generated from PD caused by the obstruction of main transformer components are studied by FDTD simulation in order to get more information for PD location and diagnosis. Current filament, perfect conductive cylinder and perfect conductive spiral coil models are used to simulate the radiation and the influences of iron-core and transformer coil to the propagation of EM waves.The results demonstrate dynamic propagation process of EM waves in time order, and prove the correctness of the shortest optical path principle. But the attenuation and distortion of EM waves-especially the first peak amplitude-caused by the obstruction of large solid conductive obstacle like iron-core are quite intensive that it may cause great difficulties to identify exact arriving time position of incident waves coming along the shortest optical path. While the influences of the coil to the propagation of EM waves are so little that HF EM waves can penetrate it in almost linear path.