Maximum power point tracker applied in batteries charging with PV panels

• Author(s): Vieira, Jose António Barros ; Mota, Alexandre Manuel
• Date: 2008
• Persistent ID: http://hdl.handle.net/10400.11/1011
• Origin: Repositório Científico do Instituto Politécnico de Castelo Branco
• Subject(s): Photo voltaic panel; MPPT; Battery charging; SEPIC; Renewable energy
• Document Type: Article
• Language: English

Description

“Copyright © [2008] IEEE. Reprinted from IEEE International Symposium on Industrial Electronics, 2008. ISBN:978-1-4244-1665-3 -8. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [e-mail]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.” This work deals with the design and a prototype implementation of a real time maximum power point tracker (MPPT) for photovoltaic (PV) panel aiming to improve energy conversion efficiency. This MPPT algorithm is integrated in the charging process of lead-acid batteries making an autonomous system that can be used to feed any autonomous application. The photovoltaic system exhibits a non-linear i-v characteristic and its maximum power point varies with solar insolation and temperature. To control the maximum transfer power from a PV panel the Perturbation and Observation (P&O) MPPT algorithm is executed by a simple microcontroller ATMEL ATTINY861V using the PV voltage and current information and controlling the duty cycle of a pulse width modulation (PWM) signal applied in to a DC/DC converter. The schematic and design of the single-ended primary inductance converter (SEPIC) is presented. This DC/DC converter is chosen because the input voltage can be higher or lower than the output voltage witch presents obvious design advantages. With the P&O MPPT algorithm implemented and executed by the microcontroller, the different charging stages of a lead-acid battery are showed and executed. Finally, experimental results of the performance of the designed P&O MPPT algorithm are presented and compared with the results achieved with the direct connection of the PV panel to the battery.