A Combined Time-and-Frequency-Domain Model for Wind Power Generation

Wind power generations (WPGs) are different from traditional generations for their considerable fluctuations. It is challenging to describe the status of a system with power fluctuation injections, especially when considering complicated network constraints. This paper proposes a combined time-and-frequency- domain (CTFD) model to evaluate whether the constraints will be violated under fluctuating wind power injection. The constraints of energy units and branch power flow are described in a generalized form, and are related to the power spectral density of power fluctuations. The distributions of the constraint variables are then discussed based on the CTFD model, and a chance criterion is conducted to describe the probability of the constraints being violated. Case studies show the effectiveness of the proposed model.