  The electrical distribution system is moving toward a more decentralized,
complex, and dynamic system. The system is experiencing a higher penetration of
distributed energy resources, flexible resources, and active end-users, leading
to an active distribution system. If these components are used actively, they
can have a positive effect on the distribution system's reliability. This paper
aims to investigate how a microgrid with renewable energy sources and energy
storage might influence the reliability of electricity supply in a radially
operated distribution system. The reliability is investigated from both the
distribution system and the microgrid perspective with the application of
different scenarios. The study includes an extensive sensitivity analysis. In
this study, we use our developed reliability assessment tool for distribution
networks. The tool is an open available software where the example network and
datasets are embedded. The reliability assessment tool is based on Monte Carlo
simulations where load flow calculations are included to capture the behavior
of the system and system components. In this paper, the reliability tool is
extended to include microgrids and microgrid controller opportunities that
handle interaction strategies with the distribution network. The model is
demonstrated on the IEEE 33-bus network. The result is confirmed through
statistical testing showing the statistical significance of providing support
from the microgrid on the distribution system's reliability.
