scope:

This document recommends best practices for the measurement of partial discharges using ac voltages and VHF/UHF electromagnetic sensors for quality control during routine tests on factory and pre-molded joints of HVDC extruded cable systems with rated voltage up to 800 kV. It must be emphasized that this recommended practice aims at focusing on the whole phenomenon of partial discharges, rather than solely on partial discharge pulse amplitude, in order to assess whether critical partial discharges are present in the tested object (either a factory joint or a pre-molded joint of a HVDC extruded cable system). By "critical partial discharge" it is meant here a discharge within the insulation of the object under test, excluding all external discharges that can be present during the ac voltage test, e.g., corona discharges due to HV electrodes, conducting leads related to the test setup.