PMU-based monitoring of power system stability incorporating load and voltage dynamics

The availability of high-resolution, synchronized measurements from phasor measurement units (PMUs) presents an opportunity to develop advanced analytical techniques for evaluation of power system dynamic performance. This paper proposes a PMU-based technique for online monitoring of power system stability. The algorithm of Maximum Lyapunov Exponent (MLE) is used to determine if a power system swing leads to instability. Advanced models are applied to consider the frequency dynamics of the loads and voltage dynamics of the generators. The effectiveness of the proposed techniques is illustrated on a 179-bus system model. The results show that the MLE technique predicts system stability in real-time. It is also illustrated that, with the extended models, the accuracy for stability prediction is further improved.