STATIC ELECTRIFICATION EFFECTS IN TRANSFORMER OIL CIRCULATING PUMPS

The work reported herein was aimed at determining whether or not static electrification production mechanisms could be present in the external oil circulating system of a power transformer. Several techniques were utilized. These were, monitoring the leakage current from 1) insulated pipe sections, and 2) conducting probes introduced into the flowing oil. The value of the charge contained in the oil was determined using a recently developed absolute charge sensor. Acoustic Emission detection techniques were also used in order to detect any partial discharges resulting from significant charge separation build-up in any one location. Although doubts exist relative to the quality of some of the data obtained, sufficient evidence was collected to show that under certain conditions the oil circulating pump could be a significant contributor to static electrification levels in operating power transformers. © 1990 IEEE