Probabilistic Analysis of Power System Frequency Stability Considering Wake Effects of Wind Farms

Most existing studies on probabilistic frequency stability (PFS) affected by the uncertainty of wind power generation ignore the heterogeneity and interactions of wind turbines inside wind farms (WFs), i.e., wake effects (WEs), which will lead to inaccurate results. This paper proposes a method for analyzing PFS considering the WEs of WFs. Firstly, an analytical WE model suitable for PFS analysis is proposed. The proposed time-saving WE model can be easily integrated into the original frequency response model of power systems and comprehensively consider multiple types of terrains, the wind direction, and the time delay of wind flow, reflecting the WEs of WFs more realistically. To analyze the system frequency and the area-level frequency simultaneously and consider the implicit relationship between them, the multiple output Gaussian process regression is designed to improve efficiency and accuracy. Case studies are carried out to verify the effectiveness of the proposed method and demonstrate the necessity of considering the WEs of WFs in PFS analysis. Moreover, the impact of the wind direction, the terrain, and the layout on PFS is investigated.