Abstract
Effect of spherical metal particles on partial discharge in oil Immersed Insulating system was investigated theoretically and experimentally. Weakest link theory was applied to calculating the breakdown probability and the average breakdown field using the Welbull parameters of clean oil. Spherical copper particles of the same size were introduced to the oil immersed Insulating system by counting the number exactly. The partial discharge inception field was measured with the precise partial discharge monitoring system. The experimental results were consistent with the results analized theoretecally. It is thought that partial discharges are initiated at the triple junction of oil, pressboad and particles where the electric field is the highest In the oil immersed insulating system.
