STOCHASTIC MULTIOBJECTIVE GENERATION DISPATCH OF COMBINED HEAT AND POWER-SYSTEMS

A new stochastic formulation of multiobjective optimisation for combin ed heat and power system dispatch is presented. Both the power and hea t demands are treated as random variables. The three objective functio ns to be minimised are: the total generation cost, the expected power generation deviation and the expected heat generation deviation. As th ese objectives are in conflict with each other, only a non-inferior so lution can be reached. The goal attainment method is used to solve thi s multiobjective optimisation problem by assuming that the decision-ma ker (DM) has desired a certain goal for each of these objectives. Very often, the DM finds it difficult to define the relative importance or a merit function among improving individual objectives and reducing c onstraint violations. A fuzzy decision index is proposed here to provi de the best-compromise solution among all objectives and constraints, and a means of maximising the most underachieved objective. A genetic algorithm approach is also proposed to help the DM to search for such a solution mathematically. Application results of the method to a seve n-generator sample system are presented.