Prediction of Voltage Stability by Using L � Index in Power System

Abstract

The prediction of voltage stability experiences sizable anxiety in the safe operation of power system. As power systems grow in their size and interconnections, their complexity increases. Hence, power system voltage stability and voltage control are emerging as major problems in the day to day operation of stressed power system. In this paper investigation of voltage stability index for voltage stability assessment has been discussed. At a normal operating condition L- index gives information about system state. There are so many indicators which predict the system condition. The objective of this paper is to develop a fast and simple method, which can be applied in the power system to estimate the voltage stability margin. Thereby an indicator is derived from the static power flow and Kirchhoff�s-Laws, which is aimed at detection of the voltage instability. This voltage stability index can work well in the static state as well as during dynamic process. It can also be used to find the vulnerable spots of the system. IEEE-14 bus system is used for test set.