Economic issues of power systems are formulated as optimization problems to enhance reliable operation and safe security of the real-time and hierarchical systems including complex control structures. The optimization problems have been formulated as combination of objective functions and constraints which Optimal Power Flow (OPF) must be increased to combine security constraints. The OPF problem is basically a network analysis challenge and the main objective of this challenge is to plan and to predict the undesirable situations that may arise by adding various assumptions to the account. This challenge can be solved using well-known numerical approaches, however these include derivatives and the solution of them is relatively difficult. However, the Evolutionary Computation (EC) based optimization algorithms provide more easy solutions for the OPF. In this chapter, the algorithms that contain the heuristic methods used on EC based algorithms and their applications on OPF are described.