A Novel MPPT algorithm for PV systems under variable Shading Conditions using Horse Herd Optimization

Abstract

Photovoltaic cell or PV cell effectively acts as a current source, primarily dependent on the incident solar irradiation. Due to the non-linear current-voltage (I-V) & power-voltage (P-V) characteristics of PV cells, power will be transferred depending upon the load voltage. So, the operating point or the load voltage should be monitored continuously and placed in such a manner so that maximum power can be extracted from the PV system. Perturb & Observe (P&O) method is one of the popular and commonly used methods used to track the maximum Power Point or MPP under uniform insolation. During partial shading conditions, it is observed that multiple peaks exist in the case of a large PV system, one of which is only a global peak (GP) and the rest are local peaks (LP). This paper investigates the failure of the P&O method and proposes a new optimization technique namely Horse Herd (HH) optimization to find the global peak during partial shading. This paper also compares the result with other optimization techniques in terms of efficacy. A simulation model of PV array is developed in MATLAB software, and I-V and P-V characteristics are studied during partial shading conditions. Further studies were conducted to overcome the problem and track the global peak successfully during various shading patterns using Horse Herd optimization technique.