Meysam Montazeri - Kerman Graduate University of High Technology
Hamed Pourgharibshahi
Mohsen Mohammadian - Shahid Bahonar University of Kerman

This paper presents extended Continuation Power Flow (CPF) method to assess voltage stability of Iran South-East power system. The alculation identifies the weakest bus where remedial action may be needed for voltage support. This method employs a predictor-corrector scheme to find a solution path of power flow equations that have been reformulated to include a load parameter. This method finds a continuum of power flow solutions starting at some base load and leading to the steady state voltage stability limit (critical point) of the system and cause well-conditioned at and around the critical point. A particular difficulty being encountered in such research is that the Jacobian of a Newton-Raphson power flow becomes singular at the steady state voltage stability limit. This paper demonstrates how singularity in the Jacobian can be avoided by slightly reformulating of the power flow equations and applying a locally parameterized continuation technique. Even more information is available from intermediateresults. In fact, both a voltage stability index and an indicator of weak buses are available at almost no extra calculation cost by analyzing the tangent vector at each step.

Static Voltage Stability, Continuation Power Flow, Iran South-East Power System