Can voltage security indices predict voltage collapse problems in large-scale power networks?

The authors give the necessary conditions needed for voltage collapse indicators (VCIs) to predict voltage collapse phenomena in a power system. At least two VCIs are needed: one for the static mechanisms and the other for the dynamic mechanisms. It is found that VCIs cannot correctly predict an impending voltage collapse. What type of voltage collapse phenomena can be predicted by the VCIs depends on whether the VCIs monitor the steady-state operating point or the dynamic operating point.<>