AC Breakdown Characteristics of A Novel Three-Element Mixed Insulation Oil for Power Transformer

Insulation oil is an indispensable part of the power transformer for the role in insulation and cooling. In order to find out a more ideal insulating liquid for power transformers, our team has developed a new type of three-element mixed insulation oil based on analyzing the advantages and disadvantages of mineral oil and vegetable oil. Most properties of this oil are superior to mineral oil, and more importantly, the oil has the ability of retarding the aging rate of insulation paper in oil-paper system. To promote its safety engineering application, this paper furtherly analyzes the alternating current (AC) breakdown characteristics of this oil. The AC breakdown voltages of the three-element mixed insulation oil with different moisture contents and temperatures were measured. Results show that the AC breakdown voltage of the three-element mixed insulation oil is much better than common mineral oil, especially at higher moisture content and temperature. The three-element mixed insulation oil has better AC breakdown property than common mineral oil.