Expanding the diagnostic impact of power factor testing

Sa？etak The Narrow Band Dielectric Frequency Response (NBDFR) test method consists of a series of power factor measurements ranging from 1 to 1000 Hz. This aggregate of the CHL (primary to secondary) measurements constitutes the dielectric response of the test specimen. The subsequent evaluation consists of a geometric analysis of a plot where the measured power factors and corresponding frequencies are graphed. As an insulation system ages, the response migrates towards the high frequency end of the plot. When the frequency corresponding to the lowest magnitude within the response (the trough) is used as a reference point, the movement of the response may be quantified; enabling the transformer may be classified in terms of condition