Small-disturbance angle stability enhancement through direct load control part I-framework development

This paper is the first of a two-part paper on the application of selective direct control of loads for small-disturbance angle stability enhancement in power systems. The change in the utility business model and developments in enabling technologies open up new possibilities for power system reliability enhancement. This paper proposes preventive modulation of selected loads through direct control for small-disturbance angle stability enhancement. An analysis framework based on the structured singular value theory has been proposed in which the controllable load range at selected buses that satisfies the desired stability robustness performance criterion is determined. Two conceptually different approaches for analysis of load modulation have been presented. Results have been presented on an equivalent of the Western Electric Coordinating Council system in the second part of this paper.