Generation Rescheduling Methods to Improve Power Transfer Capability Constrained by Small-Signal Stability

Abstract

Small-signal stability, often in the form of low frequency oscillations, has been found to be the limiting factor when determining power transfer capabilities in a number of power systems. This paper proposes a new strategy to improve the power transfer capability constrained by small-signal stability by appropriately rescheduling generation based on sensitivity analysis. In the proposed strategy, a small-signal stability index, which can be computed quickly and reliably, is used to determine the small-signal security status of a system and also for the purpose of contingency screening. Two sensitivity-based dispatch methods are proposed to reschedule the generation in order to maximize power transfer subject to the small-signal stability constraint under a set of selected contingencies. The effectiveness of the proposed methods is demonstrated by comparing with other generation dispatch methods on a real power system model.