The effect of nitrogen sparging on the long term stability of the breakdown electric field strength of a repetitively pulsed oil dielectric switch

This paper explores the effects of water concentration on the repeatability of the breakdown strength of poly-a olefin, or PAO. Poly-a olefin is a synthetic oligomer based on the n-decene molecule, and has been used in previous investigations by this group. The dissolved water concentration of PAO was initially increased to 23 ppm; higher water concentrations were found to be very difficult to obtain. The breakdown characteristics of the oil were then studied by alternately taking bursts of shots followed with intervals of drying the oil. In this manner, the breakdown characteristics of PAO were studied until an ultimate water concentration of 15 ppm was achieved. The investigation found that breakdown was not significantly affected by dissolved concentrations of water in the range of 15 to 23 ppm.