Work

Current harmonic emission of string inverters based on cable length on a large grid-connected PV plant

Year: 2025

Type: article

Abstract: The integration of solar photovoltaic systems into distribution networks has grown significantly, bringing benefits but also power quality challenges, such as harmonic distortion. While harmonic emissions from PV inverters have been widely studied, the impact of cable length on harmonic behaviour in large-scale grid-connected PV plants remains underexplored. This work analyses the harmonic emissions of three photovoltaic string inverters in a 35 MW PV plant with varying cable lengths. Key findings reveal that even harmonics (excluding H2) decrease with longer cables, acting as a low-pass filter, while odd harmonics show no clear trend, suggesting additional influencing factors such as inverter switching characteristics. Notably, H2 exhibits an inverse relationship, increasing with cable length. THD I is inversely related to power levels, with THD I below 2% under stable irradiance. Distinct emission patterns are observed at different power levels, with H5 and H7 showing strong power dependence. These results highlight the importance of cable length and power conditions in mitigating harmonic distortions, addressing a critical research gap and offering insights for renewable energy integration.

Source: International Journal of Electrical Power & Energy Systems

DOI: 10.1016/j.ijepes.2025.110909

Authors: A. Carretero-Hernandez, S. Martin-Martinez, E. Artigao, E. Gomez-Lazaro

Institution: University of Castilla-La Mancha

Language: English

Topic: Power Quality and Harmonics

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Industry, innovation and infrastructure, Affordable and clean energy

Open Access status: gold

Estimated APC paid: $3,920