Aging diagnostics of power transmission cable insulation byfluorescence techniques

摘要

A number of spectroscopic investigations have been conducted onConductor Products, Inc. Distribution cable, with cross-linkedpolyethylene as the insulation, subjected to accelerated aging tests.The principal finding of the study is that measurement of the ratio ofXLPE inherent fluorescence at 580 and 650 nm, under 514.5 nm Ar-laserexcitation, provides a means of determining remaining cable life.Penetration profiles of fluorescent dyes show promise in this diagnosticeffort as well. Other fluorescence studies, such as bow-tie treeexamination, although potentially useful in elucidation of agingprocesses, were not found useful in remaining cable life diagnostics.Service-aged sample, albeit necessarily few, have been examined. Theemerging trend is that low fluorescence ratio and/or high fluorescenceintensity are associated with long service life. The opposite is foundfor cables that have failed quickly. To firm up this trend, extensivedata bases will be needed. Samples of ethylene propylene rubber cableshave been examined. Substantial fluorescence changes occur on aging. Astudy akin to that performed for XLPE is called for