METHODS OF PARTIAL DISCHARGE MEASUREMENT IN NITROGEN, OXYGEN AND MIXTURES BETWEEN: STATISTICS OF PD MEASUREMENT AND FIRST RESULTS

Summary

The Partial Discharge measurement of medium voltage (MV) gas insulated switchgear becomes more important. A lot of manufacturers of MV gas insulated switchgears had introduced this measurement as a factory test for quality assurance to qualify the proper insulation of the switchgear. According to the discussion of prohibition of SF6 other isolation gases were investigated in the last years for the usage in gas insulated switchgears according to their breakdown behaviour. To use the Partial Discharge measurement as a factory test for quality assurance the Partial Discharge behaviour of the substitute gases should be characterized. This paper presents for a characteristic Partial Discharge defect in gas insulated switchgears the concerning Partial Discharge behaviour including the pattern in nitrogen, oxygen and mixtures. It was found, compared to air the characteristic Partial Discharge quantities show a statistical spread and totally different Partial Discharge pattern. Thus the paper includes a proposal for a method of statistical measurements of Partial Discharge quantities and patterns in such gases. As well as the Partial Discharge behaviour at 1 and 2 bar gauge pressure was compared, based on this method. The presented failure is of fundamental behaviour and show surprisingly characteristic shapes of the Partial Discharge quantities and patterns, which should allow the classification to that type of Partial Discharge defect. So this method could support the identification of the part concerned inside the MV gas insulated switchgears in such gases, too.

Additional informations

Authors

Pietrow, Miller