Coordination between long-term decision process and day-ahead unit commitment in deregulated markets: A fuzzy hierarchical bi-level modeling approach

GenCos need the day-ahead unit commitment solutions in deregulated markets which are feasible, applicable in practice and consistent with the long-term planning decisions. However, such decisions are both vast in scope and different in nature so that applying a monolithic approach is subject to some difficulties and shortcomings. This paper aims to coordinate the long-term decision process with the day-ahead market scheduling through developing a profit-based fuzzy hierarchical bi-level approach. First, an annual planning model with monthly periods at power plant-generation technology level; then based upon a monthly scheduling with daily periods at generating unit level. An interactive solution method involving the soft coordination and feedback mechanisms using rolling horizon strategy is also presented. In the developed models, we try to address critical aspects of power system optimization. This approach is implemented for a real case and analytical results are reported.