Perspective on spatially-resolved diagnostic methods for power cables

In modern power networks supply reliability is still one of the fundamental requirements. In this context, the information about condition and even remaining lifetime of power cable grids and related equipment is interesting. Especially methods with spatial resolution are of interest due to the wide spectrum of applicability in cable networks. In this paper current methods in use like time and frequency domain reflectometry (TDR and FDR), line resonance analysis (LIRA) or approaches like the standing wave principle will be briefly introduced, compared and evaluated. This evaluation will be performed in terms of practicability, reliability and reproducibility of measurements. Some key requirements regarding the measurement can be defined. First, different and unknown parts of a cable transmission line should be acquired and determined correctly by the method of choice and the spatial resolution should be as accurately as possible. Second, the measurement method must be non-destructive with the aim that the cable condition will not be degraded. Further development of such diagnostic methods will be presented and discussed. The implementation of a measurement method with a spatial resolution of the physical condition of cables causes different problems, which will be specified in this article. New approaches are necessary that lead to a reliable and accurate measurement system with spatial resolution of the power cable condition.