Three-phase inverter based on isolated SEPIC/CUK converters for large-scale PV applications

Alotaibi, Saud and Darwish, Ahmed and Williams, Barry W. (2023) Three-phase inverter based on isolated SEPIC/CUK converters for large-scale PV applications. International Journal of Electrical Power & Energy Systems, 146. 108723. ISSN 0142-0615 (https://doi.org/10.1016/j.ijepes.2022.108723)

[thumbnail of Alotaibi-etal-IJEPES-2023-Three-phase-inverter-based-on-isolated-SEPIC-CUK-converters-for-large-scale-PV-applications]
Preview
 Text. Filename: Alotaibi_etal_IJEPES_2023_Three_phase_inverter_based_on_isolated_SEPIC_CUK_converters_for_large_scale_PV_applications.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo
Download (7MB)| Preview

Abstract

Modular multilevel inverters (MMIs) for medium-voltage (MV) grid-connected systems are gaining attention in solar photovoltaic power (PV) applications. Existing MV power electronic converters require large passive components, huge line-frequency step-up transformers, and additional conversion power stages for maximum power extraction. This paper presents a new three-phase modular inverter (TPMI) based on a novel dual-isolated SEPIC/CUK (DISC) converter for large-scale PV (LSPV) plants. The proposed TPMI is synthesized from series DISC submodules (SMs) to reduce the size and improve the performance of the energy conversion system. Employing high-frequency transformers (HFTs) into the SMs can provide the required galvanic isolation and voltage boosting in addition to reducing the size compared with line-frequency step-up transformers. The chosen DISC converter reduces the required filtering capacitances thanks to its operation as a current-source converter, resulting in improved lifetime, scalability, and resilience of the inverter. The state-space model of the DISC is presented and its performance in PV grid-tied systems using simulations is evaluated. To validate the mathematical analyses and computer simulations, a small-scale experimental prototype is built and tested.

CORE (COnnecting REpositories)