IEEE Power & Energy Magazine - January/February 2016 - 80

Profiles (see the section "cIm
Profiles for Data exchanges") are
TSO n
TSO 1
defined to name the specific subset
of classes, associations, and attributes from the cIm that are used for
Outage
Network Model Part
Network Model Part
Coordinator
a particular data exchange, and these
profiles are tested in the interoperApproved Outages
ability tests. The tests ensure that
the exchange content is complete
Day-Ahead
Production
and the participating actors can
Energy Market
Security Analysis
Schedules
exchange the profile and interpret it
properly. for example, in a cPsm or
cDPsm test, the instance data corfigure 10. A business process consuming data from multiple sources.
responding to the profile content is
exchanged and the participants are
then
required
to
use
that
data
to solve a power flow. This proves
✔ equipment in the functional model (Powersystemresurce cIm class) relates to physical equipment in the participant is able to accept the data and interpret properly.
each profile will result in a set of tests that will validate
the asset model (asset cIm class). This makes it possible to answer a question such as the following: what the profile contents and prove that the test participants can
is the serial number and actual short circuit current accurately receive and act on the data. The exact tests will
(asset model) of the breaker I am currently using in depend on the profile and the use cases that were originally
used to generate the profile.
position Q1 (functional model) in my substation?
✔ registered resources in the market model relate to
generating units in the functional model. This is useful Data Composition by Receiving Systems
when a production schedule from the market is vali- one of the main objectives of the cIm is to support utildated with congestion forecast (cf) (e.g., in intraday ity business processes that normally require the assembly
cf/day-ahead cf) or used in a security constrained or composition of data from a number of sources. These
unit commitment.
sources may use different exchange technologies, differThese are just a few examples of many relationships ent (but related) schema or structure, and different content
between the different parts of the cIm. relationships like which is often referencing content from other sources.
this enable cross navigation between data exchanged accordThere are two main ways cIm data is partitioned:
ing to different profiles. Two use cases building on the above
✔ partition by instance, e.g., by transmission operators
examples follow.
or modeling authority
✔ a supervisory control and data acquisition system
✔ partition by profile, e.g., by the kind of data such as
typically needs to be persistent after it is initially
static network equipment model or topology data.
exchanged. The master resource identifier attribute, figure 10 shows a business process (day-ahead security
Identifiedobject.mrID, is included in the cIm to analysis in this case) consuming data of different forms
provide a common method for persistent, unique iden- from a number of sources, including multiple transmission
tification. when used in a data exchange, the Identi- system operators.
fiedobject.mrID is required to be unique within the
figure 11 shows how the exchanges of figure 10 can be
context of the exchange. Global uniqueness is achieved implemented using the cIm. By considering all exchanged
by using universally unique identifiers (UUIDs), data conforming to a common semantic model, we can
which is strongly recommended but not required.
describe how data from different technologies, sources, and
In an ideal data exchange, UUIDs would be used as the profiles will compose within a receiving system.
Identifiedobject.mrIDs to uniquely identify all objects, but
we expect the semantics and object identities to be
this cannot always be achieved when working with existing valid across technologies such that, for example, outages
applications that already have other established methods of (exchanged by XsD-based Xml) could relate to the network
unique identification. In this case, cIm naming attributes model (exchanged by rDf-oriented cImXml). additionand classes such as the name attribute on Identifiedobject or ally, we may exchange both full models and incremental
the alternate name classes name, nameType, and nameTy- changes to be applied to full-model descriptions. Instance
peauthority can be leveraged.
data from different sources and different profiles can link
together given the sources share consistent identities and the
profiles share some classes in the canonical cIm.
Interoperability Testing of Profiles
at the most detailed level, the data receiver may compose
any given workflow or data exchange will use only a fraction
of the classes, associations, and attributes defined in the cIm. information by matching object identities, typically and most
80

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Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - January/February 2016