Robust PSS design using H∞ loop shaping method over variations in inertia constant of SMIB system

摘要

Low frequency oscillations are one of the major problems which can adversely affect stability of power system. In order to repress this problem; usually a power system stabilizer is used. Performance of Conventional Power System Stabilizer (CPSS) will degrade due to any deviation from its quiescent operating state. Variations in system inertia constant; significantly play a role in causing the low frequency oscillations; which in turn affect the power system frequency. The inertia constant also affects the manner in which a disturbed system regains its steady state. So a robust PSS is required to achieve a good frequency stability for single machine infinite bus (SMIB) system; which can attain robustness against variations in inertia constant. This paper elucidates the; H∞ loop shaping method to design a PSS for a simplified Heffron-Phillips model of SMIB system. Designed robust PSS ensures the robustness of the system against parameter variation in inertia constant. It also ensures the stability and has superior oscillation damping capacity against system inertia constant.