Identification and Control of Electrical Noise in Routine-Reel Corona Detection of Power Cables

The analytical study of the power separator-filter type of discharge detector, when used to measure corona on long lengths of cable and the use of this type detector in cable factories over a period of years, together with a suggested procedure to determine the partial discharge-voltage stress (corona factor) characteristic has been presented. The detector itself, when used in a cable factory, is only part of a circuit arrangement which necessitates the interconnecting of the high-voltage supply, the detector, and the reel of the cable under test in environments sometimes with large amounts of electrical noise. The sources of electrical noise and their relationships to the parameters of the detector itself are discussed, noise suppression procedures which optimize the circuit arrangements are outlined, and sensitivities in the range of several picocoulombs are obtained in cable factory environment using normal test personnel.