On the Application of Pmu Measurements to System Stability Analysis

This thesis proposes a method to analyze power system stability by utilizing PMU measurements. As the current power system is operated close to its limits, stability is of high concern for both operators and customers. The implementation of phasor measurement units across the power system allows for accurate and fast stability monitoring and analysis. To address the application of PMU measurements to stability monitoring, we propose the use of circuit equivalent ideas for both voltage and angle stability. This method is applicable for on-line steady-state stability assessment, without knowing the system topology. For voltage stability, parameter estimation methods are investigated to address the tradeo between accuracy and computational speed. For angle stability, a modi ed model is presented to re ect the fact that the main change of the system occurs inside the equivalent system. Next, by taking advantage of PMU high measuring frequency, which provides a high resolution to monitor the systems, a frequency domain analysis based method is proposed to estimate the system equivalent inertia, which enables further dynamic stability analysis. The methods are illustrated with several simulated and real case studies. These algorithms are identi ed as e ective and simple methods to analyze system stability.