Fluid insulation breakdown due to repetitive electric fields

A facility to study the breakdown effects of reprate high voltage pulsing on insulating materials has been developed. The unique high voltage and data acquisition and control instrumentation are briefly described. Two insulating fluids, a transformer oil and Fluorinert FC-77(/sup R/ ) were subjected to increasing amplitude, 5.0 microsecond pulses at 1, 10, 100, and 1000 Hz rep-rates until breakdown occurred. These tests demonstrate a quick method for characterizing the short term voltage withstand of the materials. They also contribute to an understanding of the roles of heat and charge flow in breakdown phenomena.