Modified Perturb and Observe MPPT Algorithm for PV System under Fast-Changing Environmental Conditions

Abstract

The perturb and observe (P&O) algorithm is
a very common and extensively used maximum power
point tracking (MPPT) method for photovoltaic (PV)
system because of its simple design and economical
implementation. However, this technique fails to
distinguish the effect of change in irradiance from the
effect of perturbation step under fast-changing
environmental conditions. It takes a wrong decision at the
first perturbation step during sudden change in solar
irradiance and consequently, it suffers from instabilities
and power loss. This paper introduces a modified P&O
algorithm to tackle such problems. It incorporates an
additional irradiance control loop in the observation
process of conventional P&O algorithm to recognize the
actual cause of change in power. The proposed approach is
simulated and analyzed in MATLAB/SIMULINK
environment, and the performance of the both
conventional and modified algorithms is compared during
steady and rapid change in solar irradiance. The
simulation results of the proposed technique demonstrate
that it tracks the maximum power point accurately and
enhances the efficiency of the PV system by extracting the
additional power during the rapid variation in weather