Effects of transmission line faults on dynamic voltage stability

In recent years, there has been an increasing interest for the analysis of dynamic voltage stability on power systems. It is well known that induction motor loads have a particularly hazardous role in the voltage stability. On the other hand, in transmission systems loaded by induction motor loads, configuration changes such as line tripping, may cause voltage collapse. Moreover, if there is a fault on transmission lines, the disturbance effect will then significantly increase the possibility of voltage collapse. In this study, a transmission system subjected to different faults on different locations is examined from the viewpoint of voltage stability. The study shows that in the certain cases of paralleled transmission lines, single or double phase tripping of a faulted line will have positive effects on voltage stability, instead of all three phase tripping.