Microgrids are clusters of distributed energy resources, energy storage
systems and loads which are capable of operating in grid-connected as well as in offgrid
modes. In the off-grid mode, the energy resources supply the demand while
maintaining the voltage and frequency within acceptable limits whereas in the gridconnected
mode, the energy resources supply the maximum or nominal power and the
network voltage and frequency is maintained by the grid. This chapter first summarizes
the structure and control principles of microgrids. It then briefly introduces the
structures and control perspectives of distribution static compensators (DSTATCOMs).
Finally, some applications of DSTATCOMs are discussed in microgrids. The
introduced applications are power quality improvement due to the presence of
nonlinear and unbalanced loads, voltage regulation and balancing, and interphase
power circulation in the case of the presence of single-phase energy resources with
unequal distribution amongst phases. Each application is illustrated by examples,
realized in PSCAD/EMTDC.
Keywords: Distribution static compensator (DSTATCOM), Interphase power
circulation, Load compensation, Microgrid, Voltage regulation.