Eigenvalue Based Stability Improvement of Electric Power Systems Through Voltage Regulation

Abstract

In power systems operation, it is increasingly important to keep the bus voltage within a permissible range for the reliable operation of power systems. This paper presents an eigenvalue based real time stability evaluation scheme and a real time stability control scheme through voltage and reactive power regulation to keep the stability margin within a pre-specified range.  Reactive power regulation is realized on a small sized energy capacitor system composed of electrical double-layer capacitors for the stabilization control. Voltage control is also achieved through the reactive power regulation on the energy capacitor system. Nonlinear simulations for efficient demonstration of the proposed stability control scheme are carried out on a model of multi-machine system developed in Matlab/Simulink environment. In the simulations, full sets of the excitation systems including power system stabilizers and the speed governing control systems including the turbine systems are utilized. Simulations results clearly show the efficiency of the proposed stability control.