A verification experiment for comparing digital and analog measurements of time-varying harmonics

This paper presents laboratory results on the behavior of time-varying harmonics caused by an electronic converter under a voltage sag and load variations in order to demonstrate the validity of digital time-frequency decomposition methods. A filter centered on the 7
^th
harmonic is used to capture the analog signal and its output is compared with the corresponding harmonic derived by digital signal processing techniques for physical and analog verification purposes. This approach allows engineers to look into the transient phenomena through the observation of the behavior of time-varying harmonics for a better understanding of associated causes of the signal characteristics.