Improvement of Dynamic Voltage Stability in a Resilient Microgrid based on Smart Inverters & SVC

The microgrid (MG) has emerged as part of the technological transition to smart grids. The MG can operate in two modes: connected to a distribution network or in an isolated stand-alone way. When the transition to island mode occurs, the M G must operate in a stable, reliable, and resilient way. In this context, the distributed energy resources (DERs) that are part of the M G must respond optimally to guarantee dynamic voltage stability (DVS) and to improve operational resilience. Under resilient contingency conditions, the voltage stability and reactive power control of the MG is severely compromised. Therefore, even though DERs based on smart inverters operate according to the low-voltage ride-through (L VRT) requirements stated at the IEEE Standard 1547–2018, it is not enough to supply the reactive power deficit. Thus, this paper aims to include FACTS (flexible ac transmission systems) type compensation devices, particularly a static var compensator (SVC) that operates in coordination with DERs of the MG. The results obtained are satisfactory, and it is shown that the smart inverters used for the DERs and the SVC device operating with a coordinated control strategy improved the DVS, allowing the control of the reactive power supply and granting an adequate level of operational resilience in the isolated MG.