Database support for condition assessment of distribution power cables

Abstract

Due to the service life of distribution power cables the insulating materials are subject to structural changes. In most cases these changes can be seen as a degradation of the insulation properties of particular power cables. In order to detect changes in the insulation at an early stage and to gain insight to the maximum service life of a power cable, predictive maintenance is often recommended and in several cases already in use. To enable predictive maintenance the need arises for structured condition assessment of the power cables, by the use of diagnostic techniques. While the actual aging processes generated by the interaction of partial discharges are not well understood at the present time, there has been much information of a qualitative nature gathered over the years. To support electrical engineers in the interpretation of diagnostic measurement results and recognition of aging processes in the insulation of power cables, linkage between specific insulation characteristic with the combined information as provided by quantities of the used diagnostics is necessary. Because of the large amount of components, the diversity of component types and measurement data, information systems are needed for storage, correlation and comparison of measurement data on specific components and specific component types. This contribution discusses the pitfalls and application of the combination of condition assessment, diagnostics and information systems applied to distribution power cables.