Optimal initial duty for improved MPPT under change in irradiances and partial shading conditions

Solar photovoltaic cells are widely used in renewable energy power generation. The efficient operation of these photovoltaic (PV) system is based on maximum power point tracking (MPPT). Various MPPT methods have been proposed to increase the output of a PV system. But confusion arises when choosing the optimal MPPT algorithm and its parameters such as perturbation time and initial duty. This paper examines the optimal initial duty and perturbation time to improve the performance of conventional MPPT techniques under uniform shading and partial shading. During the change in irradiances, at the initial irradiance the Modified P&O tracked MPPT faster because the modified P&O had less settling time during changes in irradiance for different initial duty ratios. During partial shading conditions, the TCT generates more power than the S and SP topologies and modified P&O tracked the MPPT in less time. However, at the high duty ratio, the P&O and INC gave similar results, which were better than the modified P&O. It was also observed that the initial duty ratio (Di) in the MPPT algorithm had a negligible effect on TCT configuration under partial shading conditions. These findings help in various applications for PV systems.