An efficient GWO MPPT for a PV system using impedance information acceleration

ABSTRACT

This paper presents a novel maximum power point tracking (MPPT) method based on the grey wolf optimisation (GWO) technique for photovoltaic (PV) power generation systems. The proposed method utilises previous working duty cycles and their corresponding voltage and current data to compute the instantaneous DC impedance of a PV string. To determine the peak power characteristics of any PV string, the impedance variation of that PV string is used as an efficient shading factor. This shading factor simplifies the calculation of the GWO-MPPT algorithm to obtain multiple peak targets under partial shading conditions. Thus, the efficiency of the proposed power tracking technique can be improved considerably. The effectiveness of this method was validated through both simulation and hardware implementations. Results revealed that the search performance of five iterations of the proposed method was similar to that of ten iterations of a traditional GWO-MPPT method under normal conditions without shading. These results confirm the practicability of the proposed method in various applications.

KEYWORDS:

• Photovoltaic power generation system
• maximum power point
• Grey Wolf Optimization
• partial shading
• power converter

Acknowledgments

The author is greatly indebted to the PV Division of Delta Electronics, Inc. for providing their valuable operating experience and system data. This work is supported by the Ministry of Science and Technology, Taiwan, under project MOST 107-2622-8-006-015.

Disclosure statement

No potential conflict of interest was reported by the authors.