“…The operation, reliability and efficiency of the interconnected power system are strictly relied on the system frequency (Gomaa Haroun and Li, 2017). Therefore, several controller strategies in the different fields of control theory namely fuzzy logic controller (Cam and Kocaarslan, 2005; Nanda and Mangla, 2004; Subha, 2014), intelligent-based adaptive controller (Gomaa Haroun and Li, 2019a, 2019b; Kazemi et al, 2003; Wu, 2012), decentralized controller (Tian and Yue, 2015), robust controller (Bevrani et al, 2004; Sun et al, 2016), and sliding mode controller (SMC) (Guo, 2019; Mi et al, 2019; Prasad et al, 2019) have been established to deal with LFC problem over the preceding decades. On the other hand, classical methods like PID controller and its variants incorporated with heuristic methods due to the simple structure and easily design are extensively established in the literature as supplementary controller to accomplish the control objectives in LFC problem.…”