Toward multiple maximum power point estimation of photovoltaic systems based on semiconductor theory
Journal
Progress in Photovoltaics: Research and Applications
Journal Volume
23
Journal Issue
7
Pages
847-861
Date Issued
2015
Author(s)
Abstract
Environmental conditions, such as temperature, non-uniform irradiation, and solar shading, deeply affect the characteristics of photovoltaic (PV) modules in PV-assisted generation systems. Several local maximum power points (MPPs) are found in the power-voltage curve of PV systems constructed by series/parallel-connected PV modules under partially shaded conditions. The characteristics of PV systems change unpredictably when multiple MPPs occur, so the actual MPP tracking (MPPT) becomes a difficult task. Conventional MPPT methods for the PV systems under partially shaded conditions cannot quickly find the actual MPP such that the optimal utilization of PV systems cannot be achieved. Based on the p-n junction semiconductor theory, we develop a multipoint direct-estimation (MPDE) method to directly estimate the multiple MPPs of the PV systems under partially shaded conditions and to cope with the mentioned difficulties. Using the proposed MPDE method, the multiple MPPs of the PV systems under partially shaded conditions can be directly determined from their irradiated current-voltage and power-voltage characteristic curves. The performances of the proposed MPDE method are evaluated by examining the characteristics of multiple MPPs of PV systems with respect to different shading strengths and numbers of the shaded PV modules and also tested using the field data. The experimental results demonstrate that the proposed MPDE method can simply and accurately estimate the multiple MPPs of the PV systems under partially shaded conditions. The optimization of MPP control models and the MPPT for PV systems could be achieved promisingly by applying the proposed method. Copyright © 2014 John Wiley & Sons, Ltd.
Subjects
maximum power point (MPP); maximum power point tracking (MPPT); multipoint direct-estimation (MPDE) method; p-n junction semiconductor theory; partially shaded irradiation; photovoltaic (PV) modules/systems
SDGs
Other Subjects
Electron emission; Irradiation; Maximum power point trackers; Photovoltaic cells; Solar power generation; Maximum power point; Maximum Power Point Tracking; multipoint direct-estimation (MPDE) method; Photovoltaic modules; Semiconductor theory; Semiconductor junctions
Type
journal article