Correlating Digital Measurements of Electrical Quantities and Related Images on Micro Discharges under High Voltages

Relatively new tools such as digital systems for measuring and analyzing partial discharge (PD) quantities and radio-interference voltage (RIV) levels, UV cameras, besides high resolution digital scopes, have been available in the market. Some of them have not been considered in the relevant standards yet. In order to correlate some results obtained with the application of these tools to quantify and observe an electrical phenomenon such as PD, an experimental work was done in a test set up using different test cells under high voltages (HV). Two types of test cells with different gap arrangements in air were built: one with an ordinary needle to plane gap and other with a floating electrode. The cells were energized under AC voltages from 3 to 20 kV. At each voltage level, measurements were done using digital measuring systems for PD, RIV and electric current. Additionally, common digital pictures and movies recorded by a UV camera were performed focusing the cell discharge region. The results showed consistent correlations within the same family of results. The day light UV camera was able to capture detailed dynamic images without any change in the indoor ambient light.