The effect of electronegative dissolved gases in transformer oil

The effect of conduction current and breakdown on insulating liquids is of practical importance in all applications in which fluids are used as insulants and coolants which are circulated either by natural or by forced convection. The significance of the conduction currents lies in the fact that they may be regarded as breakdown initiating events which in the absence of appropriate conditions may not lead to complete breakdown. The subject of this paper is to present some experiment results showing the conduction current-stress characteristics in transformer oil. All tests are carried out using electronegative gases such as perfluorocarbon (C₈F₁₈, C₈F₁₆O), SF₆, perfluorocarbon/SF₆ mixtures and perfluorocarbon/N₂ mixtures as dissolved gases. The effects of applied hydrostatic pressure (0.3 MPa) are also reported