Technical regulations, together with market regulations, can have a major impact on the
development of distributed generation systems. Those technical protocols reflect
emerging interoperability across elements of the electricity system, which affects how
easily devices can connect and information can flow across the system. For DER
resources to succeed and contribute most effectively to the grid, they will need both
standardized physical interconnections to the networks and standardized information
exchange. Interoperability can hasten DER integration; the lack of interoperability can
slow or obstruct installation of DG and effective interactions between devices, device-gogrid,
and back-office integration by the grid operator.
A large number of international standards have been developed or are under
development for the connections of different types of DG. These are, however, voluntary
unless a specific organization or legislation requires adopting these standards. Hence,
worldwide there are a large number of additional national or regional standards,
requirements, guidelines, recommendation or instructions for the interconnection of DG.
Regarding the connection of DG to an electrical network, different working groups
elaborate on the development or maintenance of standardized documents. European
countries significantly participate in the International Electrotechnical Commission (IEC)
and in European Committee for Electrotechnical Standardization (CENELEC). Parallel to
these and partly in co-operation the standardization work in the Institute of Electrical and
Electronics Engineers (IEEE) is going on.
These working groups were concentrating initially on one type of DG, taking into account
also the connection aspects to the electricity network. However the basic principles for
interconnection are common and do not always depend on the type of DG. Therefore, a
more recent approach comes up, where connection of a DG is treated irrespective of the
type of ‘primary’ energy.
Annex 1 gives the summary on the most relevant standardization work.
Data communications architecture and application object models for DER are described
in draft standard proposals such as UCA-DER and IEC 61400-25. These are based on
IEC 61850 standards and their scope and point of view are around power distribution
automation. In the UCA-DER and IEC 61400-25 draft standard proposals, electricity
market interface, DER and load management issues are not included and the possible
separation of distribution and trade businesses is not taken into account. While these
and other IEC 61850 based standards deal with automation issues the Common
Information Model (CIM) for power system energy management is defined in the
standards IEC 61970-301:2003 (Energy Management System Application Programming
Interfaces EMS-API) and IEC 61970-302:2004. The objective of CIM is to support the
integration of between EMS systems, or between an EMS and generation and
distribution management systems.