High voltage VLF testing of power cables

This publication describes a laboratory test program conducted with the objective to develop a test that would replace the existing dc withstand test. The article describes the methodology used to establish the voltage duratlon and magnitude of VLF (0.1 Hz) high voltage field tests suitable for crosslinked polyethylene @WE) Insulated power cable. The results show that the voltage breakdown of laboratory aged XLPE cable at 0.1 Hz Is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz cause very little damage to the cable, and that 0.1 Hz testing appears to be a satisfadory alternate to dc testing. Preliminary values are SUggeStQd for voltage magnitude and time duration of cable acceptance, main-tenance and proof tests at 0.1 Hz for XLPE cable ratad up to 35 kV. A program is underway to similarly evaluate samples of serviceaged XLPE cable; as well as to demonstrate the use of the preliminary test values at typical utility installations.