Improvement of dynamic voltage stability in a microgrid using a DSTATCOM

Presently, electric power systems based on microgrids are reaching an important position in different locations around the world. The multiple distributed generation technologies employed in modern microgrids allow a joint operation of renewable and non-renewable energy sources with many types of loads. Nonetheless, induction motor (IM) type dynamic loads represent one of the most critical factors that make microgrid systems vulnerable to scenarios that could trigger voltage instability. This paper proposes the incorporation of FACTS (flexible ac transmission system) devices to improve the dynamic voltage stability of microgrids with high dynamic load penetration. The work focuses on the impact of including a DSTATCOM (distribution static compensator) in a microgrid with high IM type dynamic load penetration when a fault occurs that causes the microgrid isolation. Various case studies are analyzed using the CIGRÉ microgrid test system. The results show the improvements in the voltage stability of the microgrid with the coordination of distributed generation technologies and the DSTATCOM.