Maximum Loadability Estimation for Weak Bus Identification using Line Stability Indices

At present, the voltage stability assessment experiences sizeable agitation in the safe operation of power systems. This is due to the blow of a strain power system. With the accretion of power demand by the consumers and also the ambit amount of power sources, therefore, the system has to perform at its maximum accuracy. Consequently, the cardinally to discover the maximum ability boundary prior to voltage collapse should be undertaken. A preliminary warning can be perceived to avoid accost capacity of power system. This has necessitated the employment of techniques for determination of critical point of voltage stability. In this paper some important aspects related to voltage stability indices use in electric power system are discussed. The line indices are used for estimation of the maximum loadability and in other words indices are used to identify the weak bus in the system. The effectiveness of the analyzed methods are demonstrated through numerical studies in IEEE 14 test bus system, IEEE 30 test bus system and IEEE 118 test bus system, using Fast Voltage Stability Index (FVSI) and Line stability index (L mn ) at base loading and heavy reactive loading. This will be very useful in placement of optimal FACTS devices for enhancement the margin of voltage stability.