Simulation and analysis of a major disturbance in Entergy system that resulted in voltage collapse

In June 2005, severe weather in the Western Region of the Entergy System precipitated forced interruption of three critical lines in the same right-of-way. Loss of these lines led to a fast voltage collapse within the Western region. Within seconds, the generation and other critical lines in the area tripped, and over several minutes Western Region separated from the rest of the system. System studies were performed to replicate the disturbance and understand the cause of the fast voltage collapse. This paper discusses the events that led to collapse, modeling issues related to simulation and the results of the steady state and dynamic analysis.