Unit commitment problem for wind turbines power generation with batching characteristics consideration

The unit commitment problem is to determine the start-up/shut-down schedule and economical dispatch schedule of thermal generators, wind turbines and batteries to meet system load demand, reserved constraints, minimum up/down time constraints and other constraints within a certain time horizon. In order to reduce the power supply instability when wind power generation is plugged in the grid, coordinated scheduling of battery energy storage system introduced into the gird and wind turbines is performed. As a large number of wind turbines are plugged in the grid, the difficulties and complexities of the problem are increased significantly. In this paper, from a new batching perspective, we group wind turbines based on their physics locations to formulate the problem. In order to improve the performance of the batch model, a transformation method of model parameters is proposed. For tackling the complicated batch model and its NP-hardness, we develop a Lagrangian relaxation (LR) algorithm. In order to accelerate the algorithm, a surrogate subgradient Lagrangian relaxation algorithm is derived, in which subproblems are solved approximately. The experimental results show that the proposed batch model is superior to the ordinal single-unit model. Compared with CPLEX 11.0, the Lagrangian relaxation algorithm based on the batch model can obtain high quality solutions in a relatively short computation time. ©, 2015, Acta Automatica Sinica. All right reserved.