Harmonic Voltage Effect on the Breakdown and Failure Probability Characteristics of Oil-Paper Insulation Based on Experimental Analysis

This paper carries out a different frequency and different content of harmonic voltage breakdown test results for insulation mineral oil-immersed pressboard, analyzed the impact of the harmonic voltage frequency and content on the breakdown voltage, calculated the impact of the harmonic voltage frequency and content to the oil-immersed pressboard breakdown probability and obtained the impact law of different harmonic voltage frequency and content to on the oil-immersed pressboard breakdown characteristics: the breakdown voltage of oil-immersed pressboard under the action of harmonic voltages of different frequencies and contents superimposed on the power frequency voltage decreases significantly compared with the breakdown voltage at the power frequency voltage, and there was a large drop in breakdown voltage with superimposed 250 Hz and 650 Hz harmonic voltages. As the superimposed harmonic voltage content increases, the drop in breakdown voltage increases, when the harmonic content of the superimposed 650 Hz harmonic voltage increases from 3% to 20%, the decrease in breakdown field strength of the oil-immersed pressboard increases from 17.46% to 20.74%. The breakdown probability of oil-immersed pressboard increases with the superimposed harmonic voltage under the same electric field strength.