Comparison of Low-Frequency and High-Frequency Partial Discharge Measurement

Connor Chan
Iris Power LP

End users and manufacturers of rotating machines have been using Partial Discharge (PD) tests as a means of assuring the quality of stator winding insulation for many years.  A variety of sensors and measuring instruments are available to detect PD.  Together they form measurement systems that work either in the Low Frequency range (less than about 1 MHz) or in the Very High Frequency range (over 30 MHz). 

The advantages and disadvantages of these two approaches will be discussed and compared in this paper.  Machine owners generally prefer the Very High Frequency method because they can perform the tests on-line easily and interpret the results themselves with a relatively low risk of false indication.  Manufacturers can choose either way to check PD off-line at the factory for their internal quality control purpose because it is a better controlled electrical environment.

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Connor Chan has been employed with Iris Power LP, Canada, since 2001 and is currently Rotating Machines Engineer.  Prior to this position, he was Field Service Manager.  Connor Chan graduated in Electrical Engineering from the University of Hong Kong.  He is a member of the Institution of Engineering & Technology (formerly the Institution of Electrical Engineers), the Institution of Engineers Australia and the Institute of Electrical and Electronics Engineers, and is a Chartered Engineer.  He has co-authored a number of conference papers and journal articles.