IEEE Power & Energy Magazine - July/August 2017 - 37

Microgrids are being deployed in increasing
numbers and places and for different applications
and contexts.

prescriptive and providing sufficient latitude for users to
choose from a range of implementations and options to better meet the requirements of a given application. Regarding
microgrid standards, a clear and simple set of required core
functions needs to be defined and used for conformance
testing to ensure interoperability of the offerings from different vendors, even though differing implementations are
possible. Defining core functions is the purpose of the IEEE
P2030.7 standard initiative.
In addition to defining a set of core functions, there
needs to be a protocol for conformance testing. This step
forms the basis for a certification program to ensure conformance. Testing is covered in the IEEE P2030.8 standard
project. An appropriate procedure needs to be determined
for compliance testing for the standard. There needs to be a
clear and comprehensive set of test scenarios, performance
requirements and specifications, and test metrics. There are
a number of ways to deal with certification. Self-certification can be an effective solution for more established standards. However, independent validation of performance is
desirable. This can be carried out by third-party accredited
test laboratories, which ensures true interoperability of the
equipment built to meet a specific standard. Conformance to
the standard may not necessarily guarantee interoperability.
Generally, a broad market adoption is the best indicator of
the success of a standard.

Standardization Process
The guiding principle and approach for developing a standard for microgrid control systems include the following:
✔ defining a generic microgrid with basic devices and
elements common to microgrids (Figure 2), as per
definition of the microgrid
✔ identifying the main functions and features common
to microgrids meeting the definition and having,
among others, grid connection and islanding capabilities, as per functions required for a microgrid
✔ identifying generic classes of functions 1) internal to
the microgrid, to manage of microgrid assets, and 2)
external to the microgrid, to define the interactions
with the distribution management system
✔ defining the minimum required core functions for
the microgrid control system (functions associated
with steady-state operation and transitions between
grid-connected and islanded modes, which are the
basic modes of operation of microgrids)
july/august 2017

✔ defining features of core functions that have measur-

able, verifiable, and quantifiable performance metrics.
The main element of the standardization process is the
definition of core functions of the microgrid control system.
These are the functions that need to be standardized. The
others can be tailored to the specific application and remain
proprietary. The standard is a functionality-driven specification and does not deal with detailed engineering and design
implementation issues.

Scope of a Standardized
Functional Specification
To be as generic as possible and achieve the widest possible
adoption, the functional requirements specified in a standard
should be generally applicable to all microgrid control systems,
regardless of their specific requirements, configuration, and
application and whether they are connected to a distribution
network or islanded. To meet the requirements listed previously, the following are excluded from the scope of a standard:
✔ the specification of the individual or aggregate capacity of loads or generation installed in the microgrid
and the voltage levels at the point of interconnection to
the distribution grid or within the microgrid
✔ the prescription of protection schemes deployed within the microgrid, consisting of protection functions for
individual components and assets and of protection
coordination that may be required with the distribution grid protection schemes
✔ planning, design, and operating procedures of the
microgrid
✔ considerations related to the contractual power exchanges between the microgrid and the distribution network
at the point of interconnection.
The core features of the microgrid control system should be
functional and not refer to or specify any particular type of
equipment type and hardware or software implementation.
The grid operator to which a microgrid interconnects,
typically the DSO, has requirements that need to be met at
the point of interconnection. These include technical requirements such as anti-islanding, fault isolation, low or high
voltage and/or frequency ride-through, and power quality,
as well as operational requirements related to real and reactive
power import and export. The microgrid as an entity, including
the microgrid control system, needs to satisfy these interconnection requirements. These should not limit the applicability
of the standard to DSOs.
ieee power & energy magazine

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