Time-Scale Separation Designs for Performance Recovery of Power Systems With Unknown Parameters and Faults

In this brief we apply several time-scale separation designs for robust stabilization and performance recovery to multimachine power systems with two commonly encountered classes of uncertainties, namely matched additive uncertainty (e.g., line outage) and input multiplicative uncertainty (e.g., load or generation changes). We illustrate the effectiveness of the designs in eliminating undesired performance such as the possibilities of a Hopf bifurcation and subsequent voltage collapse in a single machine infinite bus power system. We also demonstrate the application of one of the designs to fault recovery of a classical 9-bus system.