Economic Dispatch: A Mixed-Integer Linear Model for Thermal Generating Units

Economic Dispatch (ED) is a major study in operation of a power system. Using the ED study, the power system operators determine the optimal power production of generating units to achieve the minimum total generation cost. To reach the global optimum solution of ED, this paper develops a linear ED model using the mixed integer linear programming (MILP) formulation. The non-linear equations of the full AC load flow model are linearized using Taylor series expansions and piecewise linear (PWL) approximation techniques. The IEEE 14-, 30-, 39-, 57-, 118-, and 300-bus standard test systems are employed to evaluate the accuracy and efficacy of the presented linear AC load flow model. The simulation results of the MILP-based ED model are compared with those obtained by the conventional non-linear programming (NLP) approach. The developed model is optimized using GAMS software.