A new paradigm of automatic generation control under the deregulated environments

Power system restructuring has been a world-wide trend, requiring innovations in the EMS (energy management systems). The AGC (automatic generation control) is also required to be innovative for adaptation to the market systems with several kinds of bidding strategies. In order to achieve the economic optimality, the AGC scheme should be designed to take into account the bidding results. Under the deregulated environments, it is necessary to have a two-level hierarchy for the AGC: the upper level AGC deals with the system frequency control and the optimal generation allocation to IPPs based on the ACE (area control error), and the lower-level AGC deals with only optimal generation allocation to the generation units. In the AGC, the penalty factor plays an important role for the optimal generation allocation. Under deregulation the transmission loss evaluation for the individual plant becomes more important than that for the whole system. This requires the introduction of slack-bus independent penalty factors. In this paper a new paradigm of AGC is discussed with the two-level hierarchy