Design of Damping Controller Based on the Wide-Area Signal Strength

Due to enduring nature, low frequency oscillation (LFO) modes are most critical modes in a power system. Therefore, these modes should be identified to design proper control mechanism. In this article, wide-area power system stabilizer (WAPSS) is designed to dampout the low frequency inter-area mode. First using detailed model of power system, linear state-space model is obtained at a stable equilibrium point. Then critical inter-area mode is identified amongst all low frequency oscillation modes using small-signal stability analysis. Furthermore, based on highest geometric measures of joint controllability and observability, control loop is selected. Phase compensation and gain of WAPSS are determined by classical residue method and eigenvalue sensitivity method respectively. The proposed method of WAPSS design is tested on 4-machine 11-machine power system and comparatively complex New England-New York 16-machine 68-bus power system. Results obtained on MATLAB/SIMULINK® platform shows the satisfactory damping performances with WAPSS for small disturbances.