A predictor/corrector scheme for obtaining Q-limit points for power flow studies

This work proposes a new continuation power flow method tracing QV constraint exchange points (CEP), at which generators regulating voltages hit the reactive power limits. The proposed method is based on a predictor/corrector scheme to obtain CEPs in succession. The condition for Q-limit immediate instability is derived and used in the algorithm, where the stability of the obtained CEP is checked in each iteration. The point of collapse method is also combined in the algorithm to detect a saddle node bifurcation. The effectiveness of the proposed method is demonstrated through numerical examinations in IEEE 118 bus systems.