Dynamic equivalencing of power systems using bus impedance matrix

• Generating dynamic equivalent models for real-time security assessments. • Frequent updating of the external equivalent model. • Bus impedance matrix can be used to generate equivalent models in frequent intervals. • Dynamic simulations with equivalent boundary loads and generators. • Matching fault levels with equivalent circuits. In real-time power system operations, frequent assessment of system operating limits for large, interconnected networks through dynamic simulations is critical for maintaining stability and reliability for system operators. To address the associated computational challenges and reduce simulation time, portions of the network must be represented using equivalent models. This paper introduces a methodology that involves solving a set of linear equations to develop equivalent models at regular intervals, reflecting real-time system conditions. The proposed structured and repeatable methodology facilitates the frequent updating of the external equivalent model while limiting the computational burden to practically acceptable levels. The dynamic simulation results for the study area, comparing the full system model and the reduced model derived through the proposed methodology, demonstrate a high degree of consistency. While the proposed methodology exhibits certain limitations, it also presents notable strengths, which can be further explored and refined to enhance the accuracy of the reduced model.