Abstract:
Recently the utility is facing severe voltage stability problems so that to satisfy end users exponential
growth of energy demands. As a solution, considering high operational cost of constructing new power
generation, transmission and distribution system the utility is connecting more loads on existing load buses up
to their thermal limits. But in power system increasing inductive load brings voltage stability problem due to
an armature reaction. Thus, if we connect an additional inductive load, the armature reaction is subtractive to
the main field, resulting in voltages fall-down and hence yields further voltage collapses. In
addition, since under heavy load the line absorbs more reactive power than it generates, leads to transmission
line stresses and its fall down when it exceeds maximum thermal limits. Therefore, this article targets
finding voltage stability margins of load buses and ranking them based on their severity indexes for reactive
load power changing using user modified voltage stability indices and recommending further solutions
