**Nature-Inspired MPPT Algorithms for Partially Shaded PV Systems: A Comparative Study**

**Somashree Pathy 1, C. Subramani 1,\*, R. Sridhar 1, T. M. Thamizh Thentral 1 and Sanjeevikumar Padmanaban 2**


Received: 22 January 2019; Accepted: 8 April 2019; Published: 16 April 2019

**Abstract:** PV generating sources are one of the most promising power generation systems in today's power scenario. The inherent potential barrier that PV possesses with respect to irradiation and temperature is its nonlinear power output characteristics. An intelligent power tracking scheme, e.g., maximum power point tracking (MPPT), is mandatorily employed to increase the power delivery of a PV system. The MPPT schemes experiences severe setbacks when the PV is even shaded partially as PV exhibits multiple power peaks. Therefore, the search mechanism gets deceived and gets stuck with the local maxima. Hence, a rational search mechanism should be developed, which will find the global maxima for a partially shaded PV. The conventional techniques like fractional open circuit voltage (FOCV), hill climbing (HC) method, perturb and observe (P&O), etc., even in their modified versions, are not competent enough to track the global MPP (GMPP). Nature-inspired and bio-inspired MPPT techniques have been proposed by the researchers to optimize the power output of a PV system during partially shaded conditions (PSCs). This paper reviews, compares, and analyzes them. This article renders firsthand information to those in the field of research, who seek interest in the performance enhancement of PV system during inhomogeneous irradiation. Each algorithm has its own advantages and disadvantages in terms of convergence speed, coding complexity, hardware compatibility, stability, etc. Overall, the authors have presented the logic of each global search MPPT algorithms and its comparisons, and also have reviewed the performance enhancement of these techniques when these algorithms are hybridized.

**Keywords:** photovoltaic systems; MPPT technique; partial shading; global MPP (GMPP); nature-inspired algorithms
