A Continuation Power Flow Tracing Q-Limit Points on Bifurcation Diagrams in Power Systems

Abstract

This paper proposes a new type of continuation power flow method tracing Q-limit points where the reactive power limits of generators are encountered. The proposed method consists of the predictor scheme to estimate Q-limit points and the corrector scheme to obtain their converged solutions. The condition for Q-limit immediate instability is derived and used in the algorithm. All of them are different from the conventional schemes. The proposed method when combined with the Point of Collapse methods quite effectively provides the converged solution for the critical loading condition which is either the immediate instability point or saddle node bifurcation. This implies that the proposed method can compensate the drawbacks of the existing methods such as the Point of Collapse methods and the continuation methods. The effectiveness of the proposed method is demonstrated through numerical examinations in IEEE 118 bus system.