Development of VLF test system for power cables

Abstract

with the rapid growth of the using of power cables in distribution network, a large demand for mobile high-voltage cable test systems is expected in the near future. VLF test system has a great equivalence of AC test, so it is wildly used in power cable test. In this paper, a novel VLF high voltage generator, based on LCC resonant converter, is introduced detailed. The Extended Describing Function (EDF) is used to select parameter of LCC resonant converter. In order to generate a true sinusoidal test voltage, the control strategy, concluding changing duty cycles of LCC resonant converter and load resistors, is proposed. The generator can generate a sinusoidal test voltage of 20 kV at 0.1 Hz and the result shows that the total harmonic distortion can meet the requirement of IEEE 400.2 standard. Keywords-VLF test system; power cables; extended describing function (EDF)