Abstract
This paper introduces a coordination technique for a multi-objective generation scheduling of thermal generating system. Today's quality requirement for electrical power makes power system operators to minimize generation cost, while maintaining environmental condition and transmission security as desired. The priority of these objectives may change according to load pickup rate, weather, and other various conditions. However, these objectives are usually in a trade-off relation-ship and often non-commensurable. Therefore, it is difficult to handle by conventional approaches which optimize a single objective function. In this approach we measure the adaptability of performance indices, including economy, NOx emission, and transmission security, by membership functions in fuzzy set theory. Maximization of the fuzzy decision-making function, formed by combining the adaptability indices, yields a coordinated solution of the multi-objective optimization problem. The definition of a membership function, reflecting an operator's vague intention, influences the solution of the multi-objective problem, thus enables to incorporate system operator's varying strategy, realizing a flexible operation according to system operating conditions.
