Influence of absorbed water and temperature on dielectric loss of oil-impregnated paper insulation

Abstract

Early in 1961, four oil-impregnated paper cables were energized at the Cornell High-Voltage Cable Testing Facility for operation at 345 kv. Each cable is capable of transmitting more than 500 MVA. As part of the research effort connected with the development of low loss insulation for one of the four cables, it seemed desirable to obtain quantitative estimates for the effect of absorbed water on dielectric loss of high voltage paper cables even though there were several estimates already available in the literature. However, these estimates seemed inadequate for several reasons. Either the studies had not been made on modern low-loss materials suitable for Extra High Voltage Cables, or were based on indirect estimates of water content, or appeared to lack internal consistency, or included only a narrow range of water contents. Furthermore, the agreement among the various estimates was not close.