Analysis and assessment of large scale power system voltage stability by a novel sensitivity based method

This paper presents a novel voltage stability analysis and assessment method based on an observation of the sensitivity of generator reactive power outputs to changes in loading at buses in a power system. This information can be used to assess the relative stability of a power system and to determine the sets of generators that cause voltage instability when they lose voltage control and the associated buses that provide the mechanisms for collapse. This method has been tested on a modified Cigre 'Nordic' test system and on the large scale Queensland Transmission system and the results of these tests are provided in this paper. This method is compared to another widely excepted voltage stability assessment method.