2014 Volume 7 Issue 2 Pages 122-131
This paper presents an improved Incremental Conductance - Maximum Power Point Tracking (INC-MPPT) algorithm based on fuzzy logic for photovoltaic (PV) systems. The demonstrative PV system consists of the solar array with a nominal power of 320W, a non-inverting buck-boost converter, and a resistive load. The PV system's objective is to seek efficiently the maximum power point (MPP) of the solar array in varying weather conditions. To do this, the proposed fuzzy-based INC-MPPT algorithm is designed with two sub-controllers. Wherein, in the first one, a novel fuzzy logic controller (FLC) is proposed to enhance the effectiveness of the conventional INC-MPPT. Its aim is determining rapidly and accurately the optimal voltage, where the solar array operates at the MPP. The other is a PI anti-windup controller, and it regulates the operating PV array's voltage to the optimal voltage computed in advance. Simulations show that the suggested algorithm fulfills well the listed goal even when the solar irradiance and temperature change suddenly. Furthermore, comparisons of simulation results, obtained from the presented algorithm, the conventional INC, and an existing fuzzy-based INC-MPPT, illustrate advantages of the proposed algorithm in terms of fast response speed, high accuracy, and small oscillation. The feasibility and efficacy of the suggested algorithm are also verified by experiments.