Occurrence of partial discharges in low voltage cables due to artificial mechanical injuries

In the last few years the need for the diagnostics of low voltage cables became unquestionable, e.g. power plants planning lifetime extension need information about their secondary cabling system in order to ensure safe operation. There are numerous means of diagnostics for middle and high voltage cables, but their implementation on low voltage cables has to be carried out carefully. Partial discharge measurement is an accepted and widely used method for the condition assessment of middle and high voltage cables. This paper presents the measurements carried out with the goal to investigate the ability of partial discharge measurements to detect mechanical failures in low voltage cables. Specimens with different injuries were prepared in single-core and multi-core cables. The measurement data provide opportunity to observe changes in partial discharge magnitude and the statistical parameters characterizing the discharge activity. It is also possible to evaluate the sensitivity of the measurements on the failures.