Summary:
Maintaining sinusoidal or near-sinusoidal operating conditions in electrical systems is essential, as is their accurate assessment. This letter proposes a novel metric, namely the sinusoidality index, which quantifies the instantaneous deviation of the trajectory of an ac voltage vector with respect to a circle under any periodic operating conditions. This metric differs from conventional Fourier-based estimations by accounting for the trajectory of the waveform rather than its spectral decomposition. A variety of examples illustrates the properties of the proposed metric and highlights insights that may not be captured by conventional approaches.
Keywords: Harmonic distortion, power quality, differential geometry, Fourier transform.
JCR-JIF Impact Factor and WoS quartile: 4,700 - Q2 (2025)
DOI reference:
https://doi.org/10.1109/TPWRD.2026.3709621
Published on paper: October 2026.
Published on-line: July 2026.
Citation:
J. Gutiérrez-Florensa, A. Ortega, L. Sigrist, F. Milano, "Sinusoidality Index", IEEE Transactions on Power Delivery, Vol. 41, nº. 5, pp. 2962 - 2965, October 2026. [Online: July 2026] doi: 10.1109/TPWRD.2026.3709621
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