Frequency response analysis to select the best PSS locations in power systems

It is well know that the location is a significant factor in the ability of power system stabilizers (PSS) to increase the damping of inter-area oscillations. Generally, two methodologies have been applied by most researchers to identify the best PSS locations. Controllability/observability analysis is derived from modal control theory of linear time-invariant system and participation factor analysis which is used to measure the degree of participation of a state variable in a mode. Beyond modal analysis, in this paper a frequency domain method is used to identify the best PSS location to increase the damping of an inter-area mode. The results obtained by this method are compared with those obtained by conventional methods.

I. Introduction

Electromechanical oscillation is a common problem in large electric power systems. These oscillations may occur with different features. Local oscillations are characterized by single generators swinging relative to the rest of the system, whereas inter-area oscillations are associated with the dynamics of power transfers and involve groups of generators in different areas oscillating relative to each other.