On the Existence of Voltage Collapse in Islanded Microgrid

Abstract

The future smart grid entails clusters with plug-and-play features known as microgrids. Each microgrid hosts a mix of distributed energy resources including synchronous-based. Nevertheless, synchronous-based generators, are characterised by their limited reactive power capabilities which could lead to voltage collapse problem during islanding. Microgrids also comprises controllable loads. The majority of modern loads are power-electronic-interfaced and demand voltage regulation at their ends, exhibiting constant power characteristics. Microgrids with high penetrations of constant-power loads are vulnerable to voltage collapse especially during contingencies such as weather-caused outages. To this end, this paper investigates the possibility voltage collapse phenomenon in islanded microgrids during contingencies. The voltage stability analysis was carried out on an islanded 6- bus microgrid. Several case studies were designed in order to reveal the likelihood of voltage collapse in microgrids under extreme events.