Voltage stability in power systems is defined as the ability of a power system to maintain acceptable voltages at all the buses in the system under normal condition and after being subjected to a disturbance .
Voltage stability assessment of power system has been achieved using various mathematical formulations collectively known as the voltage stability indices , , , . These tools are used for monitoring the voltage stability condition of a power system for effective control and enhancement of its operating condition.
Many approaches have been used to analyze voltage stability but an approach that can directly indicate the closeness of power system to voltage collapse can be used to optimally plan for the improvement of the power system voltage stability condition when compensation devices are to be deployed.
Voltage stability analysis is an area of study directed towards monitoring the response of power system to continuously changing generator and load dynamics towards achieving stable and reliable operation of the electric power system , .
Voltage stability analysis and improvement remain a major concern of power system operators due to the recurrent risk of voltage collapse.
Part i☆ Energy storage systems are increasingly used as part of electric power systems to solve various problems of power supply reliability. With increasing power of the energy storage systems and the share of their use in electric power systems, their influence on operation modes and transient processes becomes significant.