Rapid Boundary Modification Technology for Security Region Based on Physics Guidance

Security analysis methods based on security region (SR) play a pivotal role in power system analysis. The construction of security margin contributes towards the mining of geometric and physical characteristics of a practical dynamic SR (PDSR). The traditional dynamic security region analysis method relies on approximate models, which have problems of high computational complexity and insufficient accuracy. However, the fitting method, although highly accurate, faces the challenge of combinatorial explosion in large-scale power grids. This research employs the instantaneous response trajectory of the generator, captured by the synchronous phasor measurement unit (PMU), to construct a transient stability boundary function through the examination of the curvature and inflection points of the phase trajectory and dynamic behavior attributes. By assessing the influence of power injection disturbances on stability via a sensitivity matrix, an explicit hyperplane representation for the Practical Dynamic Safety Region (PDSR) is formulated, and the computation is streamlined by utilizing relaxed nodes for dimensionality reduction. Ultimately, the approach was verified on the New England 10-machine-39-node system and an operational system in China.