High-Accuracy and Fast-Speed MPPT Methods for PV String Under Partially Shaded Conditions

Wang, Yunping; Li, Ying; Ruan, Xinbo

Abstract

The photovoltaic (PV) string under partially shaded conditions exhibits complex output characteristics, i.e., the current-voltage (I-V ) curve presentsmultiple current stairs, whereas the power-voltage (P-V ) curve shows multiple power peaks. Thus, the conventional maximum power point tracking (MPPT) method is not acceptable either on tracking accuracy or on tracking speed. In this paper, two global MPPT methods, namely, the search-skip- judge global MPPT (SSJ-GMPPT) and rapid global MPPT (R-GMPPT) methods are proposed in terms of reducing the searching voltage range based on comprehensive study of I-V and P-V characteristics of PV string. The SSJGMPPT method can track the real maximum power point under any shading conditions and achieve high accuracy and fast tracking speed without additional circuits and sensors. The R-GMPPT method aims to enhance the tracking speed of long string with vast PV modules and reduces more than 90% of the tracking time that is consumed by the conventional global searching method. The improved performance of the two proposed methods has been validated by experimental results on a PV string. The comparison with other methods highlights the two proposed methods more powerful.

Citation

Wang, Y., Li, Y., & Ruan, X. (2016). High-Accuracy and Fast-Speed MPPT Methods for PV String Under Partially Shaded Conditions. IEEE Transactions on Industrial Electronics, 63(1), 235-245. https://doi.org/10.1109/TIE.2015.2465897

• Journal Article Type: Article
• Online Publication Date: Aug 7, 2015
• Publication Date: Jan 1, 2016
• Deposit Date: Jun 24, 2024
• Journal: IEEE Transactions on Industrial Electronics
• Print ISSN: 0278-0046
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 63
• Issue: 1
• Pages: 235-245
• DOI: https://doi.org/10.1109/TIE.2015.2465897
• Public URL: https://nottingham-repository.worktribe.com/output/35447988
• Publisher URL: https://ieeexplore.ieee.org/document/7182327