Stabilizing Control in Emergencies Part: 2. Control by Local Feedback

New methods are introduced for the stabilization of the power system during violent swings after major disturbances. These techniques utilize existing or attainable measurements, computer facilities, and devices such as short rating resistors, capacitors, or fast valving. Stabilizing action is based on a new Observation Decoupled State Space which is introduced in a companion paper [1]. Components of this state space associated with individual buses can be computed locally from local conventional measurements. The origin is always the stable system equilibrium-the target of the control. In this paper methods are introduced to track this target by purely local feedback. No telemetering is involved in either the state estimation or the control. Stability of the control in a global domain was proven. Excellent performance is demonstrated by simulation on a 118 bus system with a consistent, up to ten-fold, increase in the critical clearing times.