LAUSR

This paper deals with static voltage stability assessments in the context of microgrids. It is well known that distributed systems have been changing their operation mode from passive to active due to a high level of distributed resource penetration. Hence, operating of the system in islanded mode could be considered on a routine or emergency basis, and the voltage stability analysis become vital in any planning or operation study in the distribution level of electrical power systems. In this way, this paper develops a novel formulation for voltage stability analysis in islanded systems, showing the differences with respect to traditional methodologies, mainly when they neglect the absence of a swing bus and the frequency of the system as a variable. Further, the present work compares the load margins of a distribution system when it works in both modes, in grid-connected mode and islanded mode, considering the operation strategies of the most usual Power Electronic Converters. The results are carried out in the IEEE-37 Node Test Feeder.