EPRI report-characterization of cable insulation materials by dynamic mechanical spectroscopy

A project that is part of a broad effort to apply nonelectrical diagnostics to the study of aging-induced changes in solid dielectric cables is described. The technique of dynamic mechanical spectroscopy is explained. The goal of the work described was to determine whether aging in high-molecular-weight polyethylene (HMWPE) or crosslinked polyethylene (XLPE) insulated distribution cable insulation could be detected by solid-state rheological measurements. Insulation from seven HMWPE and five XLPE cables were studied. The results and their interpretation are summarized. They suggest that a more detailed study of a number of service-aged and laboratory aged XLPE's, tree-resistant XLPEs, and EPR would be highly beneficial.<
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