No-load loss measurements of power transformers under distorted supply voltage waveform conditions

This paper describes the problem of correcting the results of no-load loss measurements of power transformers for the effect of distorted supply voltage waveform on the magnetic flux in the core and hence on both the hysteresis and eddy current loss components of core losses. Test data obtained during the no-load loss measurements of a three phase 675-MVA power transformer was reproduced at the National Research Council of Canada laboratory to demonstrate the instrumentation requirements to ensure a proper application of the correction formula.