Determination of High-Frequency Harmonic Power in Converter-Fed Motors

Abstract

This paper focuses on usage of frequency domain power analysis on harmonic power extraction in converter-fed motor measurements. Synchronous generator and frequency converter supplies are compared in 16 operating points from low load to rated operation point including supply frequencies of 12.5, 25, 37.5 and 50 Hz with both supplies. The active powers of the generator and PWM supplies are decomposed to fundamental power and harmonic power and the results are compared with the traditional method that is based on total losses determined from measured input and output powers of the same measurements. Using harmonic analysis of only converter supply measurements for determining the additional harmonic losses in motors is recommended and discussed.