PMU-based model-free approach for short term voltage stability monitoring

In this paper, we propose a model-free approach for short term voltage stability monitoring of power system. Our data-driven approach makes use of Phasor Measurement Units (PMU) data to generate the stability certificate for verifying the voltage stability. We employ Lyapunov exponent, a stability tool adapted from ergodic theory of dynamical system, to generate the stability certificate. The time-series voltage data from PMU is used for the online computation of Lyapunov exponent. The proposed method can not only be used to determine the voltage stability of the entire system but can also be used to determine stability/instability contribution of individual buses to the overall system stability. Simulation results are presented on WSCC nine bus system using different load models.