IEEE Electrification Magazine - March 2016 - 22

Generator
Black Start

Transmission
Reconfiguration

Load
Restoration

Microgrid
Self-Healing
and
Restoration
Procedure

TransmissionLevel
Restoration
Procedure

Toward the Distribution Grid

Towad the Transmission Grid

Figure 4. A conventional restoration process.

Figure 5. A microgrid-based restoration and recovery.

Utility Grid DMS

Faulty Microgrid

Microgrid

Microgrid
Normal Synergy
Emergency Synergy

Figure 6. A distribution system with multi-microgrids.

I E E E E l e c t r i f i cati o n M agaz ine / March 2016

developing countries are proceeding with microgrid
implementation projects. Electricity service providers will
need to develop strategies and roadmaps for microgrid
systems based on their local specifications such as resilience, the age and condition of grid components, protection devices and control systems, public interests, prevailing policies, and economic conditions.
A promising microgrid implementation requires the
integration of hardware facilities and software applications.
At the same time, microgrid deployments all over the world
have offered some lessons:
xx
A resilient communication infrastructure is essential for a microgrid. Such a rapid and reliable communication system improves operators' situational
awareness and look-ahead capabilities, thereby
enhancing the resilience of the grid, especially in
terms of response and recovery requirements.
xx
Microgrid implementation necessitates the installation of a large number of sensors throughout substations, feeders, and load entities. The location and the
number of sensors should be optimized considering
communication technologies, power grid protocols,
control structures, and budgetary limitations.
xx
An efficient data-management scheme is a prerequisite for microgrid control approaches. This requirement includes data validation and archiving, big-data
management, bad data detection, time synchronization, etc.
xx
Shifting from a centralized operation to a decentralized one would enhance the real-time control of
microgrids and improve their supply resilience.
xx
Cybersecurity plays an increasingly prominent role in
microgrid resilience studies. Potential threats to cybersecurity often stem from the extensive use of information and communications technology (ICT) in
microgrids. As electricity grid becomes additionally
dependent on ICT, the cyberthreat in power systems
will be exacerbated.
xx
The DER integration introduces technical implications
for the planning and the operation of microgrids.
Rooftop solar photovoltaic and diesel generators
(30 kW capacity or smaller) at residential and commercial sites are the common types of DERs used in
microgrids. When a DER is owned by the utility, it can
be scheduled for improving the grid security and operational limitations. However, a utility must also consider grid-connected DERs, which will not be managed by the utility operators.
xx
From the viewpoint of a grid, DERs are not available for
frequency control due to their nondispatchable nature;
they could, however, provide capacity deferral benefits.
xx
New standards and policies are evolving for the DER
integration, interoperability, protection, control, and
communication systems in microgrids.
These tangible issues have been addressed in several
microgrid pilot projects, which have proved to be valuable

Table of Contents for the Digital Edition of IEEE Electrification Magazine - March 2016