The evolution of VLF testing technologies over the past two decades

Due to the regulation of the electricity market, the reliability of distribution networks becomes more and more important. Network operators are forced to maintain the distribution cable system carefully. Withstand testing after installation or after repair of failures reduces significantly the failure rate during normal operation. This paper describes the evolution of the Very Low Frequency (VLF) testing technology over the past two decades. Since the introduction of the VLF technology not only the technology itself has changed. Because of the large number of systems in operation and the gathered field data/performed researches, also the application has received high attention from the asset management.