Online Estimation of Region Inertia Based on Dynamic Division with Spatial-Temporal Perception

Online estimation of region inertia is critical for frequency stability analysis and control in large-scale power systems. The fixed area division scheme for traditional region inertia estimation struggles to maintain the consistency of the dynamic response of bus frequencies within the evaluation region. To this end, this paper proposes a novel online region inertia estimation method founded on dynamic division principles. To accurately identify the frequency dynamic characteristics and reasonably divide the regions, we introduce a clustering method based on the amerced derivative dynamic time warping (ADDTW) indicator. The proposed new ADDTW effectively quantifies the fuzzy differences of the frequency spatial-temporal features. Then, to obtain the accurate center of inertia (COI) frequency in realtime during the inertia estimation process, the concept of the center range of inertia (CROI) frequency is introduced. It highly approximates the COI frequency using the shape-based distance (SBD) method and correction operations. Subsequently, to reduce the identification operation of disturbances in region inertia estimation and mitigate the impact of the power-frequency asynchronism phenomenon, we introduce a two-stage region inertia online estimation method, including the differential swing equation and data processing. Case studies conducted on a modified IEEE 145-bus system validate the effectiveness and robustness of the proposed method.