Feasibility of FDA method for the detection and classification of faults in extruded HVDC cables

A methodology for localizing failures in cable systems is required to increase their availability. To localize faults, the possible fault scenarios for HVDC cables must first be thoroughly researched, identified and classified. In this article, measurements for some possible faults in cable systems using different setups are presented and discussed to determine the potential of frequency domain analysis (FDA) method for the classification of fault scenarios on DC cables. Results are based on different fault scenarios on two medium voltage cables of different lengths. It is examined which fault scenarios could be detected. In the first step, reference measurements of the fault-free test objects were measured at both ends of the cable. The measurements at both ends of the cable showed only a negligible difference. With the measurement setup for the reference images, the reproducibility, the usable measuring range and the contacting at the feed-in point of the measuring signal were also examined. After the measurements of the reference images, the correspondence of calculations of the resonance points with the measurements was verified. It turned out that the calculations provide a good approximation in the low-frequency range, but the deviations increase with increasing frequency.