Indices-based Voltage Stability Monitoring of the Italian HV Transmission System

In liberalized electricity markets the need for an increasingly flexible and economic exploitation of the grid determines more and more stressed operating conditions. The on-line assessment of system security becomes a topic of paramount importance in control centers. In this context fast indices to quickly assess system security represent a valuable support for Transmission System Operators (TSOs). This paper presents the application of some (both node-oriented and line-oriented) indicators for the on-line voltage stability monitoring in the Italian HV transmission system. The implemented analysis tool is based on a procedure written in MATLAB which both retrieves the transients of the variables of interest from a time-domain simulator and composes these variables to calculate the monitoring indices. The combination of the information derived from the utilization of these indices allows to improve operators’ situational awareness concerning voltage stability issues. A dynamic model of the Italian HV transmission grid is presented and some simulation results concerning the indices application are illustrated and commented.