“…The use of by-pass diodes has limited this problem, but power potentially available from by-passed cells is lost. Various control methods, such as such as perturb and observe (P&O) (Femia et al,2009;Killi and Samanta, 2015;Elbaset et al, 2016), Incremental conductance (IncCond) (Elgendy et al, 2012;Radjai et al, 2014;Li et al, 2016), hill climbing (HC) (Alajmi et al, 2011;Xiao et al, 2016), fuzzy logic (Messai et al, 2011;Letting et al, 2012;Cheng et al, 2015;Rezvani and Gandomkar, 2016), artificial neural network (ANN) ( Liu et al, 2013;Boumaaraf et al 2015;Lin et al, 2016;Messalti et al, 2017), particle swarm optimization (PSO) Cheng et al, 2015;Letting et al, 2012;Manickam et al, 2016;Renaudineau et al, 2015), sliding mode (Kim, 2007;Chu and Chen, 2009;Zhang et al, 2015;Mojallizadeh et al, 2016;Ouchen et al, 2016) and so on, have been proposed to enable optimal power generation from the chained PV strings with by-pass diodes and under partial shading conditions, but satisfactory solutions in terms of simultaneously maximizing the power generated and protecting the PV panels have still been a challenge (Rezk and Eltamaly, 2015;Chen et al, 2015;Liu et al, 2016;Kumar and Chatterjee, 2016;Gupta et al, 2016).…”