Sound Wave Propagation Analysis Using FDTD for Contaminated Insulator Discharge Noise

Abstract

Discharge noises caused by contaminated insulator string were studied using anechoic room where the difference of the noise waveform due to insulator shape was found. In this study, sound wave propagation of the discharge noises have been simulated using two-dimensional FDTD method to examine the effect of insulator shape on the observed waveform. In the course of the study, the shape data of the insulator was expressed as the set of elements that typify the media (air and solid), directions of air-solid (porcelain) boundary, and directions of ‘Free Space’ boundary by allocating the colors on the corresponding bitmap image file. The source points of the sound were also arranged into the bitmap. Calculated wave propagation for each time step is again expressed in the form of bitmap for visualization. The nature of the calculated sound waveforms for different insulator shapes and discharge positions are compared with that in the experiment.