Optimal sizing of large-scale wind system with time-sharing wind power curtailment

Because of the development of grids lagging behind the growing of wind power penetration level, the enthusiasm of wind farm owner is frustrated for the installed capacity being limited by the flexibility of the existing systems. There is increasing interest to use a balanced amount of wind power curtailment (WPC) as a decision variable during the high wind-speed periods and hard peaking periods to buffer the limitation, thereby obtaining an additional installed capacity and net benefit from the wind farm owner viewpoint. With taking an hour as the time scale, the effect of time-sharing wind-speed distribution and time-sharing peaking characteristics of wind power on WPC has been successfully introduced into the model. A valid strategy of time-sharing WPC is proposed herein through describing the wind-speed probability distributions in different scenarios. Based on the cost-benefit analysis, a model is established to determine the appropriate time-sharing curtailment, hereby providing the optimal installed capacity. IEEE 30 nodes system and a hydroelectric-intensive actual system in China are both used to verify the effectiveness of the proposed model. And in the case of the hydroelectric-intensive system, optimal results indicate that there is an increase of 31.56% in installed capacity and 98.64% in net benefit of wind farm by allowing a mere 4.279% curtailed energy. Meanwhile, several sensitivity analyses including the time scale, point of common coupling, confidence level, wind turbine types, on-grid price, and investment cost are conducted to evaluate the influence of key parameters on this optimal capacity. This approach can help with better understanding the interactions between curtailment and wind hosting capacity of systems.