Unit commitment considering flexibility and uncertainty of wind power generation

The uncertainty and anti-peaking nature of large-scale grid-connected wind farm bring great challenges to the security and reliability of power grid operation, especially to unit commitment. Reasonable uncertainty modeling and applying innovative optimization methods such as stochastic optimization, robust optimization and so on in unit commitment become current research focuses in this field. In existing scheduling frameworks wind farms are treated as 'passive' participants, which neglect the potential controllability such as switch of connection state and fast pitching control. Further, the economy and security of power system's operation may be decreased if ISO aims to maximize the consumption of wind power, e. g. inadmissibility of wind curtailment. In this paper, firstly the potential controllability of wind farms are discussed, and a novel scheduling framework of wind farm and corresponding unit commitment model are proposed. Under the novel scheduling framework wind farm will change into a flexible participant and in the unit commitment model the uncertain output of wind farm is simultaneously taken into account. The proposed method is verified by the modified IEEE 39-bus system, and simulation results show that under the proposed framework the overall performance of power grid operation can be effectively improved. Besides, the proposed method can be also used to evaluate the wind power accommodating ability of power grid. ©, 2015, Power System Technology Press. All right reserved.