A NEW PARTIAL DISCHARGE MEASURING SYSTEM CALIBRATOR

Mario Pecorelli
Abstract:
A new PD (partial discharge) measuring system calibrator is described. The device, battery operated, may be used either grounded or in a floating position, and generates securely mains-synchronized impulses by capacitive coupling. It allows the determination of the scale factor k and resolution time T r in PD measuring systems, and it fulfils the requirements of International Standard IEC 60270. PD measuring instruments have mains-synchronized sweeps. Hence, in order to have stationary calibration impulses in the PD measuring instrument, the calibrator must generate mains-synchronized impulses. Usually, PD calibrators synchronize to mains frequency by a photodiode. In case of insufficient pick-up of power frequency light, these calibrators automatically select an internal quartz oscillator. When the internal oscillator is on, there is usually a slight difference between the oscillator frequency (fixed) and the mains frequency (variable), and consequently the impulses generated by the internal oscillator are not stationary in the PD measuring instrument (detector screen). This new calibrator avoids that problem because it generates securely mains-synchronized impulses by capacitive coupling, making unnecessary an internal quartz oscillator.
Keywords:
PD (partial discharges), calibrator, synchronization, resolution time
Download:
IMEKO-TC4-2011-004.pdf
DOI:
-
Event details
IMEKO TC:
TC4
Event name:
TC4 Symposium 2011
Title:

XVIIIth IMEKO TC4 International Symposium on Measurement of Electrical Quantities (part of Metrologia2011, together with IX International Congress on Electrical Metrology - IX SEMETRO)

Place:
Natal, BRAZIL
Time:
27 September 2011 - 30 September 2011