计及调速系统详细模型和调频备用的大扰动下频率最低值预测方法

With the increasing proportion of renewable energy in the power system, system inertia decreases, and frequency control resources become scarcer, posing a severe challenge to system frequency stability. Therefore, in this context of ever-changing operation scenarios, it is particularly important to rapidly and accurately assess the power system frequency security indices when there are large power disturbances. Specifically, the frequency nadir, which has a highly nonlinear and unexpressed quantitative relationship with multiple parameters, making it difficult to predict accurately and quickly, is a research focus in the power system frequency security assessment. However, current methods for rapidly predicting the frequency nadir do not adequately consider the impact of frequency regulation reserves. This paper, based on a parabolic approximation of system frequency deviation for the average system frequency (ASF) model, presents an open-loop decoupling approach. This approach allows for the quantification of the relationship between the system frequency nadir and governor output power while accounting for frequency regulation reserves. Ultimately, it facilitates the rapid prediction and evaluation of the frequency nadir, considering the impact of frequency regulation reserves. The accuracy of this method is validated through case studies on a small system and the ACTIVSg2000 system, with prediction accuracies of 99.28% and 97.71%, respectively. This method is important for addressing issues related to unit commitments with frequency safety constraints, evaluating the effectiveness of frequency stability control measures, and assessing the operational capacity of new energy sources within systems subject to such constraints.