IEEE Power & Energy Magazine - July/August 2017 - 36

Not all microgrids will have the ability to carry out all tasks,
for example, enabling market participation.

Structure of a Microgrid Control System

Block 4

Grid-Interactive Control
Area Electric Power System Control, Electricity
Markets, DMS Interaction, Distribution System
Interaction, SCADA

Block 3

Supervisory Control
Generation and Load Dispatch, Optimization
(Voltage Profile, Economic), Spinning Reserve,
Reconfiguration, Black Start, Protection
Coordination, Forecasting, Data Management
and Visualization

Block 2

Local Area Control
Load Management, Energy Management,
Automatic Generation Control, Fast Load Shedding,
Disconnection, Resynchronization

Block 1

The microgrid control system functions operate at different control levels and in different time frames. They act
on different components and assets of the microgrid. The
functions range from the device-level functions, typically
embedded in the DER, to the microgrid supervisory and grid
interactive functions, as in Figure 3.
The time frame in which the different microgrid control system functions operate is specified in Figure 4. The
lower- or device-level functions run on the short timescale while the core functions typically operate on a longer

Device-Level Control
Voltage/Frequency Control, Current/Power Control,
Reactive Power Control, Generation Control,
Load Control, Energy Storage Control, Islanding
Detection, Fault Detection and Protection

figure 3. The microgrid control system function classification. DMS: distribution management system; SCADA:
supervisory control and data acquisition.

Control Level

Grid Interactive
Supervisory
Local Area
Device Level

timescale. The functions associated with transitions from
connection to disconnection and the dispatch of DER assets run on different timescales. The transition functions,
in the unplanned disconnection case, need to be executed in
a short time frame and implemented with the shortest delay.
The dispatch function can be executed at regular intervals
and a longer timescale, typically in the minute range (15 min
or lower).

Microgrid Control System
Function Standardization
Standardization Benefits and Activities
Microgrids are being deployed in increasing numbers and
places and for different applications and contexts, and new
standards defining minimum requirements would greatly
aid this deployment. Defining generic core-control functions
would facilitate the basic design of the control system and the
configuration and operation of microgrids.
Establishing a standard for microgrid control systems
would also allow interoperability of control system functions with microgrid components to enable the operation
of a microgrid through cohesive and platform-independent
interfaces. This approach allows for component flexibility
and customization and control algorithms to be deployed
without limiting extended and potential functionality.
Microgrid components and operational solutions exist with
different configurations and in different implementations.
Interoperability requirements are an integral requirement
and a principle in standards development. Standards should
allow microgrid controllers to be interchangeable from the
functional perspective.
To be useful, standards need to be universally applicable
and present as few restrictions as possible. Interoperability of
control systems from different vendors would apply and be
limited to the core functions defined in the standards.
Standardization efforts are carried out by a number of
standards organizations, such as the IEEE and IEC. The
IEEE Standards Association has initiated two projects on
microgrid standards: IEEE P2030.7 and IEEE P2030.8. This
second standard uses the functional specification defined in
the first standard.
Participants in the standards development include 1)
manufacturers offering microgrid controller configuration
platforms and configured controllers, 2) consultants specifying and configuring microgrids and microgrid control
systems, 3) service providers, 4) utilities and distribution system operators (DSOs), and 5) government and
research laboratories.

Requirements for a Successful Standard
ms

min
Time

Day

figure 4. Microgrid control function timescales.
36

ieee power & energy magazine

The ultimate aim of a standard is enabling interoperability
of diverse systems carrying out the same functions, with an
industry consensus on what is required to conform to the
standard. There also needs to be a balance between being
july/august 2017

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - July/August 2017