Locating observers and controllers for severely disturbed power system using mode matrices

In presence of large disturbances, observation of separation mechanism based on wide-area measurements and emergency controls are important and problematic tasks to restore system stability. This paper proposed a novel approach to properly locate the controllers and observers based on modal analysis. For structure preserving models, rank tests are proposed to qualify the placement to ensure the unstable modes of the disturbance controllable or observable, and the corresponding mode observability and controllability matrices are utilized to sift most sensitive sites to detect system separation and most effective sites for emergency controls to act against modes of instability. With the few sites selected, crucial measurements can be singled out from large amount of system states, and emergency controls can conveniently be combined and designed for the disturbance. The proposed placement approach is verified in 10-machine New England power system.