Probabilistic economic dispatch of generation units considering environmental aspects

Nowadays, global attentions towards using wind energy in electricity supplying system is increasing and the number of countries committed to a specific percentage of wind power in their power systems is continuously growing. On the other hand, in the developed and developing countries where power system is the backbone of economy, maintaining the supply of electricity in an economical, secure, and reliable manner is one of the most important priorities. In order to operate the power system economically, Economic Dispatch (ED) problem in power systems emerges. ED is defined as allocation of the demand among the generating units with minimum total generation costs while satisfying the system and unit constraints.;The existing methods for incorporating wind energy in economic dispatch are not mature enough to be applied in the real power system operation. The practical probabilistic economic dispatch still remains as a dilemma. In all of the previous studies on probabilistic economic dispatch, the wind energy is considered along with the thermal units with a simple quadratic cost functions. However, in real power systems, there are many different kinds of generation technologies which need to be taken into account. Combined-cycle units are one of those technologies that have never been taken into economic dispatch problem along with wind energy and thermal units.;This dissertation presents a novel optimized probabilistic formulation for the economic dispatch problem of power system considering three different kinds of generation units: wind-powered unit, thermal unit, and combined-cycle generation unit. The proposed method uses the technical and economic characteristics of all participating units in an optimization formula while applying Weibull probability distribution function as geographical characteristic of wind speed. The non-smooth cost function of the combined-cycle units is regarded in the proposed method for the first time along with the wind-powered generation units in the economic dispatch problem.;Several different simulation scenarios are considered and various sensitivity analyses are performed in this work. The results clearly show the influence of combined-cycle unit on solution of economic dispatch problem and authenticate the necessity of considering wind-powered units along with thermal and combined-cycle units.