ELECTRICAL ENGINEERING, vol.99, no.3, pp.839-846, 2017 (SCI-Expanded)
The aim of this study is to enhance the performance of photovoltaic (PV) power systems. The Perturb and Observe (P&O) maximum power point tracking (MPPT) technique is largely used in these systems. This method has two major drawbacks, which are the oscillation near the maximum power point (MPP) in static and the losing tracking direction in dynamic. To overcome these handicaps, a modified P&O algorithm is proposed. The new algorithm differs mainly from the basic one by adding the change in the PV current as a third test in its flowchart. This controller is able to track MPPs perfectly with less possibility to deviate from its tracking way. The algorithm is applied for tuning the duty cycle of a boost converter and tested under a stringent profile of sunshine variation as recommended by the EN 50530. It was found that, the simulation results are satisfactory, the convergence speed is increased and the average efficiency is improved by four percent during varying solar radiation conditions. Furthermore, the proposed PV-MPPT system does not require any extra hardware components.