Visualization of electric discharge in porous materials

Very few studies have been conducted to visualize the dynamic discharge development from ground electrode in the soil. The imaging process of the electric discharge in opaque porous materials is extremely difficult. Therefore, in this study, a photographic investigation of the electric discharge in a new dielectric glass bubble material was conducted. A Photron FASTCAM SA5 high speed camera was utilized to record the discharge light emitted from the sample. A special test rig was developed to facilitate these tests with a rod - plane electrode configuration. The material was placed in a transparent acrylic tube to allow the discharge light to be transmitted so that the camera can record the discharge. Standard lightning and switching impulse voltages were used in these experiments. Synchronized frames of the recorded video with voltage and current waveforms allow visualization of the discharge phenomenon and monitoring the dynamic change of the discharge at various times during the impulse.