Solution to Economic Dispatch by Equal Incremental Cost Criterion Introduction Economic load dispatch problem is allocating loads to plants for minimum cost while meeting the constraints. It is formulated as an optimization problem of minimizing the total fuel cost of all committed plant while meeting the demand and losses .The variants of the problems are numerous which model the objective and the constraints in different ways. The basic economic dispatch problem can described mathematically as a minimization of problem of minimizing the total fuel cost of all committed plants subject to the constraints. Reference: Birge, B., 2003, PSOt, A Particle Swarm Optimization Toolbox for Matlab, ALL THE BEST