... For this reason, various conventional mathematical solutions were presented to solve the CHPED problem such as Lagrangian relaxation (Sashirekha et al., 2013), mixed-integer non-linear programming (Kim and Edgar, 2014), branch and bound algorithm, and benders decomposition (Abdolmohammadi and Kazemi, 2013). However, introducing practical constraints such as prohibited operating zones POZs, valve-point loading effects (VPLEs), and consideration of multiple pollutant emissions have greatly extended the complexity Minimum and the maximum position of each particle in the PSO X k i,j , X k+1 i,j Current and updated position of the particle i with regards to component j To overcome the shortcomings in classical mathematical methods, recently several meta-heuristic based solutions are presented which are more effective in solving the non-convex CHPED problem such as squirrel search algorithm (Basu, 2019), gray wolf optimization (Jayakumar et al., 2016), improved genetic algorithm (Zou et al., 2019), Cuckoo optimization algorithm (Mellal and Williams, 2015), civilized swarm optimization and Powell's pattern search algorithm (Narang et al., 2017), artificial immune system (Basu, 2012), kho-kho optimization algorithm (Srivastava and Das, 2020), deep reinforcement learning approach (Zhou et al., 2020), biogeography-based learning particle swarm optimization and colony search algorithm (Song et al., 1999). However, the meta-heuristic methods are also limited by constraints such as complexity in the derivation of the algorithm in a programming language, number of tuning parameters, and execution time of the algorithm. ...