Elevating Power Quality: Three-Phase Harmonic Analysis using NI myRIO's Synchronous Reference Frame

Abstract

Harmonics in three-phase electrical networks give rise to significant power losses, necessitating their detection and mitigation to prevent these losses. This research presents the development of a comprehensive system designed to measure harmonic content and extract harmonics, thereby generating a reference signal for an active power filter aimed at harmonics reduction. The methodology leverages the Synchronous Reference Frame - Phase Locked Loop (SRF-PLL) approach to segregate the fundamental order from the harmonic signal, resulting in the isolation of pure harmonic components. The Fast Fourier Transform (FFT) method is concurrently employed to quantify the amplitude of each harmonic order. Both computational processes are executed on the NI myRio controller, programmatically configured through LabVIEW software. The constructed system exhibits remarkable performance, manifesting an average Total Harmonic Distortion (THD) error of 0.47% before and after extraction for non-triple orders, and 99.93% for triplen orders. Consequently, this harmonic extraction system excels particularly in isolating non-triple order harmonics. To optimize its functionality, current or voltage sensors with specifications tenfold the amplitude of the 50Hz AC fundamental order are recommended. Furthermore, the system showcases a remarkable frequency range, capable of accurately discerning AC signal frequencies up to 20kHz or orders as high as 400.