Test results and preliminary conclusions regarding 0.1Hz VLF testing on very long, mixed distribution feeders of 13.8 to 33 kV system voltage

This paper presents the VLF test method for distribution network feeders. The goal was to perform an evaluation to determine whether the VLF method can produce a substantial benefit over the traditional DC test in terms of predictability and confidence regarding the meantime between failures of network feeders during the summer peak season.