UHF PD signal attenuating characters when passing through transformer windings

Research has focused on studying the adaptive simulation model for transformer windings and attenuation of ultra-high frequency (UHF) signals radiated by partial discharge (PD) located inside windings. The UHF signals propagation is simulated by XFDTD 6.5 software which is based on finite-difference time-domain (FDTD) method. The attenuation of UHF in plane board model usually used by most researchers is compared with that in flat copper wire model. It is founded that the amplitudes are different obviously in the viewpoints no more than 0.5m from driving source. The UHF signals attenuate when passing through windings, especially for the PD located between windings and iron core. The attenuation is lowered for the reflection by windings or iron core.