Expanding the Diagnostic Impact of Power Factor Testing

Expanding the Diagnostic Impact of Power Factor Testing

Narrow Band DFR

Power Factor (PF) testing at system frequency has long been accepted as the standard for evaluating the condition of an oil-paper insulation system despite its limitations to small changes in resistive losses, for example due to an increase in moisture, and its challenges in identifying localized insulation problems.  Narrow Band Dielectric Frequency Response (NBDFR) is a relatively new diagnostic technique that plots PF versus frequency typically from 1 Hz to 1000 Hz.  The resultant is a graph with a wealth of diagnostic information that provides more insight into the significance of small PF changes, a better indication regarding the age impact of the insulating system, and an improved ability to detect localized problems, even in large insulation systems.  The benefit to the user is significantly improved information for critical decision making regarding transformer utilization.


To read the rest of the article, click here