Environmentally constrained optimum economic dispatch

This paper presents a general formulation of the optimum economic load dispatch problem in a system with thermal plants taking into account the constraints on emission of sulfur dioxide and oxides of nitrogen. The proposed algorithm is useful to determine the optimum mix-ratio of high sulfur content and low sulfur content fuels, to limit the sulfur dioxide (SO2) emission per hour. The emission of oxides of nitrogen (NOx) is minimised by reducing the output of the generating units with the high ratio of incremental NOx emission to incremental fuel cost. The method proposed for considering the pollution constraints is simple, and can easily be incorporated in an existing economic dispatch program. The algorithm is tested on a plant with four generating units, and the results are presented.