Assessment of voltage stability of a small island network using a developed MATLAB toolbox

This paper describes how Static Voltage Stability Analytical Assessment utilises the modal analysis technique to identify the contributing factors to voltage instability such as bus, line and generator participation factors. It also describes how Static Voltage Stability Margin Assessment through V-P and V-Q bus stability margin indices and a line stability index known as the Fast Voltage Stability Index (FVSI) provide a relative measure of the proximity to voltage collapse. These static assessment techniques were developed into a MATLAB toolbox and verified on the IEEE 14 Bus Test System with an average accuracy of 3%. A case study of the Trinidad and Tobago national grid was performed and the results obtained identified the buses, lines and generators that contributed significantly to voltage stability degradation as well as those system elements that will mitigate voltage instability.