The conventional Newton and fast decoupled load flow methods are considered to be inadequate to obtain the maximum loading point due to ill-conditioning problems at and near this critical point. At this point the Jacobian matrix of the Newton-Raphson method becomes singular, and the assumptions made for the fast decoupled formulation no longer hold. However, as shown in this paper, with small modifications these methods become adequate for the computation of the complete bifurcation diagrams. They are also adequate for obtaining a single solution near the nose point or at the lower part of PV curve with flat start initialization. These new methods are compared to each other with the purpose of pointing out their features, as well as the influence of reactive power and transformer tap limits. The results obtained for the IEEE systems (14, 30, 57 and 118 buses) show that the characteristics of the conventional methods are preserved.
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