Comparison of Low Frequency and High Frequency Partial Discharge Measurements on Rotating Machine Stator Windings Webinar – North America

Jul 16, 2020 at 1:00 PM EDT Webinar

No Charge

Live Webinar with Q&A

Join us Jul 16, 2020 at 1:00 PM EDT for our latest webinar on “Comparison of Low Frequency and High Frequency Partial Discharge Measurements on Rotating Machine Stator Windings” given by our industry expert Greg Stone.


All PD testing used to be performed in the 1 MHz (low frequency) range. Now most on-line PD measurements are made in the very high frequency (30-300 MHz) range, both on machines, as well as in transformers and GIS. This webinar will discuss our experience with both low and very high frequency testing of stator windings. Qualitrol-Iris Power is perhaps the only supplier of PD test equipment that makes test equipment in both frequency ranges.


• General IEC and IEEE PD measurement standards
• IEC and IEEE standards for measuring PD on stator windings
• Differences between PD measurements on windings as compared to power transformers, cables and gas-insulated switchgear
• Describe the frequency ranges for machine PD measurement, and present some comparison examples
• Present the advantages and disadvantages of LF and VHF PD measurement on machines for both off-line and on-line testing.


Dr. Greg Stone was one of the developers of on-line partial discharge test methods to evaluate the condition of the high voltage insulation in stator windings. From 1975 to 1990 he was a Dielectrics Engineer with Ontario Hydro, a large Canadian power generation company. Since 1990, Dr. Stone has been employed at Iris Power L.P. in Toronto Canada, a motor and generator condition monitoring company he helped to form. Iris is now owned by Qualitrol Corp. He has published two books on motor and generator winding maintenance and authored more than 200 papers concerned with rotating machine windings. Since 1980 he has also been active in creating and updating many IEEE and IEC standards. Greg Stone has a PhD in Electrical Engineering, and is a Fellow of the IEEE. He has won numerous awards from the IEC, Cigre and IEEE for his technical contributions.

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