Comparative study of MPPT algorithms under variable resistive load

This paper proposed a fuzzy logic control (FLC) based maximum power point tracking (MPPT) of a photovoltaic (PV) system under standard temperature condition (STC) and variable connected load. The PV system including a PV module BP SX150S, buck-boost DC-DC converter, MPPT, and resistive load is modeled and simulated using Matlab/Simulink package. In order to compare the performance of the conventional perturb and observe (P&O) and FLC based MPPT methods at STC (G=1000 W/m2 and T=25 °C) and rapid variation at connected load, two times, rising time (tr) and recovering time, are calculated. From the simulation results we can observe that the FLC based MPPT method can track the MPP of the PV module faster and with less tr and recovering time at transient state and effectively eliminates the power oscillation around the MPP of the PV module at steady state, as compared with the perturb and observe (P&O) method, using the duty cycle (D) of the DC-DC converter as a control variable. Hence, the PV system with the proposed tracking method has better transient and steady performances.