Engineering and Applied Sciences Journal
ISSN: 3067-8005 | DOI: 10.64030/3067-8005
Hazar Shtat
This study presents an applied methodology for deriving design parameters for neutral conductor sizing in low-voltage threephase, four-wire electrical systems supplying nonlinear electronic loads. The study addresses the combined effects of load imbalance and triplen harmonic currents on the neutral conductor and develops a calculation procedure for representing these effects within a proposed mathematical model. The methodology is based on field measurement data reported in the literature for a three-phase, four-wire low-voltage distribution system serving nonlinear electronic loads, together with published harmonic-spectrum data used to characterize the harmonic behavior of such loads. The reported phase-current and neutralcurrent measurements are examined and evaluated for their suitability for deriving the model parameters. The average phase current is determined from the reported phase-current measurements, while the neutral-current components associated with load imbalance and triplen harmonics are used to derive the corresponding model factors according to the definitions adopted in the study. The published harmonic spectrum is analyzed separately to determine the individual harmonic current components and the resulting RMS phase current, while the measured triplen harmonic neutral-current component is retained as the basis for the Triplen Harmonic Factor adopted in the proposed model. The derived parameters are subsequently combined to obtain the Neutral Conductor Upsizing Factor and to establish a quantitative basis for estimating the required neutral conductor crosssectional area during the preliminary electrical design stage. The presented procedure provides a reproducible link between reported field measurements, published harmonic data, and the design parameters used in the proposed neutral conductor sizing model.