Article 1: Power systems - from challenges and requirements to interoperable solutions
Authors: Chavdar Ivanov, Terry Saxton, Jim Waight, Maurizio Monti, Greg Robinson
Challenges when operating and developing power systems
Present and future energy policies are creating a substantial transformation of the electrical power grid
and pose a number of significant challenges to transmission and distribution IT systems that are
needed to control and manage this grid. As more of the critical business processes are being
automated and new devices and systems are being added to achieve the Smart Grid vision of the
future, the challenge rapidly becomes one of having too much data from a variety of new and
incompatible sources but too little information.
At the heart of the solution to this dilemma is the development of an overarching framework with the
goal of facilitating interoperability between the many disparate systems comprising the Smart Grid. In
this special CIM edition of the IEEE Power & Energy magazine, we are highlighting one of the most
promising solutions to achieving this framework which is based on the widely deployed IEC CIM
(Common Information Model) standards. This special edition provides the background and explains
the need of having interoperable solutions across the entire electrical energy landscape and the efforts
already underway in this area.
1. Moving environment
Today, the electricity landscape is changing faster than ever before. Generation patterns are shifting
due to the replacement of old fossil fuelled plants with natural gas and renewable energy sources,
resulting in more variability over time, more dependence on weather conditions, and energy sources
widely dispersed throughout the power network. This scenario has resulted in the need for better
prediction and control to maintain the security of supply. In addition, increased cross-border flows as
the result of merging energy markets are increasing the system complexity. Consequently, demand
needs to become more flexible, and the call for competitive electricity prices and a reliable system
becomes even more essential. This in turn impacts all areas of system planning and operation and will
require major changes in the market organisation and the market products.
This diversity of work requires us to challenge a number of current assumptions regarding the needs
of power system users, leading to the need for a new road map for the development and operation of
the power system over a variety of time horizons: short term (1 up to 5 years), medium term (5 up to
15 years) and long term (15+years).
The long-term European energy vision supported by the recent EC (European Commission)
communication on EU (Energy Union) requires a paradigm shift that must be addressed at the panEuropean level. Uncertainties derived from the large amount of variable renewable energy sources
(RES) to be integrated including offshore generation, new consumption demands, inclusion of
Demand Side Response (DSR), and energy storage, create a set of possible scenarios which, in turn,
lay the foundations for increasingly more novel infrastructure planning approaches and coordinated
system operation at the pan-European level, all supported by well adapted market design.
Similarly, the smart grid vision as articulated by NIST (National Institute for Standards and
Technology) [1] foresees a major transformation of “…the USA’s aging electric power system into
an interoperable smart grid - a network that will integrate information and communication
technologies with the power-delivery infrastructure, enabling two-way flows of energy and
communications.” Figure 1, which is a conceptual model of the smart grid, consists of seven domains,
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each of which contains multiple applications, roles, and associations realized via secure information
exchanges (or communication flows). In some countries, there is also an electrical flow from
Customer direct to Transmission.
Figure 1: NIST Smart Grid Conceptual Model
Figure 2 illustrates, as an example, the complexity of the underlying communication paths both within
a domain and between domains (of course, this is just a small sample of the many systems actually
exchanging information in the real world). The goal is interoperability between all the
systems/devices across all domains.
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Figure 2: Sample of systems/communications paths comprising the Smart Grid vision.
2. Need to adapt to the new rules
The fight against climate change together with the achievement of the Internal Electricity Market
(IEM) in Europe requires new rules, new technologies, and new ways of operating the power system.
Integration among all players, be it generators, consumers, Distribution System Operators (DSOs),
power exchanges, power suppliers or technology providers is key to the optimization of the overall
system. Transmission System Operators (TSOs) manage the backbone of the electricity supply for the
benefit of the society. The importance of this role has been widely recognized and sealed in the Third
Energy Package of the EU.
In Europe, the EC, together with many stakeholders, have established that greater effort is needed to
create a secure, competitive and low carbon European energy sector and a pan-European IEM.
Network codes are intended as a tool to reach this objective by complementing existing national rules
to tackle cross-border issues in a systematic manner. They are sets of rules which apply to one or
more parts of the energy sector. The need for them was identified during the course of developing the
Third Energy Package by the EU. More specifically, Regulation (EC) 714/2009, which deals with
conditions for access to the network for cross-border exchanges in electricity, sets out the areas in
which network codes will be developed and a process for developing them. Article 8 of this
Regulation “Tasks of the ENTSO-E (European Network of Transmission System Operators for
Electricity)”, states that “… ENTSO-E shall adopt common network operation tools to ensure
coordination of network operation…”. This includes “data exchange and settlement rules, network
security and reliability rules, interoperability rules, transparency rules”.
Meanwhile in the USA (with similar efforts elsewhere), national legislation has led to the unbundling
of previously vertically integrated utilities and the promotion of wholesale electricity markets
managed by Regional Transmission Organizations and Independent System Operators, regulated by
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the Federal Energy Regulatory Commission. NIST in recent years was assigned “primary
responsibility to coordinate development of a framework that includes protocols and model standards
for information management to achieve interoperability of Smart Grid devices and systems…”. This
framework is seen as necessary to ensure the goals of the Smart Grid vision are achievable. Without it
there is a risk that the diverse Smart Grid technologies, such as smart meters which are being widely
deployed and synchrophasors that provide real-time assessments of power system health to provide
system operators with better information for averting disastrous outages, will become prematurely
obsolete or, worse, be implemented without adequate security measures.
3. IT complexity and interoperability
With the opening of electricity markets, the complexity of products and derivatives being traded as
well as the number of business processes have increased many times over. The transactions volume
and the need to process data in ever shorter timescales required the development of an efficient
support from IT systems.
With increasing complexity of each market and greater requirement for interaction between market
areas, it became apparent that IT complexity and lack of interoperability was becoming a major
hindrance to an open and fully functional electricity market.
All of this has practical implications with intensive computer-based automation. Increasingly, such
automation depends on multiple systems at multiple locations owned and operated by multiple parties
to cooperate within defined business scenarios. It requires information produced by System A and
System B to be consumable by System C in order to produce information for System D in time frames
that may not tolerate errors or human intervention. In order to make this happen, information transfer
must not only be automated between systems that were designed independently, but the hundreds of
transfers involved in complex processes must all be informationally compatible with one another in
order to achieve the required end result.
The need of data exchange standards
The need of data exchange standards is confirmed by many utilities and industry organizations. The
integration of renewable energy sources around the world, which is also a major target of the energy
and climate policy objectives for 2020 and beyond, will affect existing electricity grid infrastructure,
operations and the functioning of the electricity market itself. The integration of renewables into the
power system requires their variability to be balanced. This can be tackled by electricity grids
operating smartly and cost-efficiently. To do this, a seamless and efficient information exchange is
necessary at various stages, between an increasing number of companies – TSOs, DSOs, generators
etc. Such information exchanges have become indispensable in network planning (HVDC network
development, interconnection development to tackle congestion, etc.); power system operation (realtime information on the generation output, balancing control, etc.); market (generation schedules,
trades, balancing resource management, etc.).
In its proposal for use of standardised component models for power flow and dynamics cases, NERC
recognized [2] a growing need for accurate interconnection-wide power flow and dynamics
simulations to analyse frequency response, inter-area oscillations and interactions between wide-area
control and protection systems. Use of proprietary approaches is preventing a free flow of information
necessary for interconnection‐wide power system analysis and model validation. The ability of the
different utilities and network operators to exchange data enables them to collaborate to understand
system issues and develop solutions.
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The objective of the recently adopted European network code on capacity allocation and congestion
management is to create the largest and most competitive electricity market in the world. The
guideline sets out the rules that will enable a transition from the current system, in which there are
different rules for electricity market participants in different countries or regions, to a single set of
electricity market rules applied across Europe. The code states “… To implement single day-ahead
and intraday coupling, the available cross-border capacity needs to be calculated in a coordinated
manner by the Transmission System Operators (hereinafter "TSOs"). For this purpose, they should
establish a common grid model including estimates on generation, load and network status for each
hour. The available capacity should normally be calculated according to the so-called flow-based
calculation method, a method that takes into account that electricity can flow via different paths and
optimises the available capacity in highly interdependent grids….”
According to the network code the common grid model “…means a Union-wide data set agreed
between various TSOs describing the main characteristic of the power system (generation, loads and
grid topology) and rules for changing these characteristics during the capacity calculation
process…”
In addition to this network code, the upcoming codes on operational security and operational planning
and scheduling will also require use of a common grid model in order to fulfill the tasks and
obligations defined therein.
The European long term planning studies, such as the Ten-Year Network Development Plan
(TYNDP) and Regional Investment Plans, demand a high degree of coordination and consistency in
the data exchanges. Without having a common data exchange standard, the task to perform credible
studies and deliver results would consume a huge number of resources. Therefore the needs are clear:
TSOs, third parties and service providers need to use commonly agreed upon and compatible data
exchange formats.
However, there are number of questions which were asked in different communities: How do we, as
an industry, define “common” methods, processes, interfaces and data? How do we ensure broad
agreement and adoption of them? How do we develop and maintain these standards and tools into the
future?
More specifically, these questions have to be answered not only between network operators, but also
with all the market participants to electricity markets. This frequently requires agreements with
national regulators and changes to national or regional regulations of markets or system access rules.
Most of the required studies relate to system development, operation and planning, security or
reliability analyses and any other studies or analysis necessary in which different parties contributing
to a study use common data sets and share the analysis work. In order to achieve this, it is essential
that the power system analyses tools are able to exchange information from other tools.
The use of standards is the only way to approach these issues. The IEC CIM set of standards has been
widely used in the last decade as the best practice to achieve interoperability. In US many utilities are
using CIM to integrate different IT applications/systems and to exchange information such as power
system network models between parties in the different regions. In Europe, ENTSO-E developed the
Common Grid Model Exchange Standard (CGMES) [3] based on the IEC CIM standards and
established a framework to assess and confirm the conformity of the suppliers’ applications to the
CGMES.
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It is a common knowledge that standards are the most effective way of achieving full compatibility
and interoperability. CIM comprises a series of international IEC standards that greatly facilitate
interoperability where multiple vendor products are involved in the exchange of common grid models
and other related information both between TSOs as well as to DSOs. While the focus of this article is
on Europe and North America, in fact CIM standards are in use all over the world including Asia,
Australia, New Zealand, Africa, and South America.
Towards end-to-end data interoperability
A necessary foundational element in satisfying these interoperability requirements of the future grid is
a common language for data – a common semantic model. This is the utility CIM, a key standard in
the USA SGIP (Smart Grid Interoperability Panel) catalog of approved standards for Smart Grids as
well as in the CEN/CENELEC M/490 SGAM (Smart Grid Architecture Models) framework standard
for Europe. The CIM helps organize and structure shared data through the use of a very complete
model of the entire power system grid and all aspects of power system management, planning and
operations to provide common semantics for information exchange.
The development of the CIM standards over the last two decades was based on strong business cases.
Multiple industry driven projects were launched to define use cases and propose the right solution
based on CIM or necessary CIM extensions. Figure 3 illustrates the complex process starting with the
task to identify business needs and collect requirements until the stage in which the applications/tools
are used by utilities, TSOs, ISOs or other entities.
Business
process’
needs /
requirements
New ideas
Use cases
Initiate new std. or
submit CIM extensions
Gap analysis
Prepare all necessary input
to initiate or update a CIM
standard
Draft std./
update CIM/
discussion
Test draft CIM standard
(standard vetting
interoperability test)
Approve and publish
a CIM standard
Standardisation process (draft a new CIM standard or update, propose CIM
extensions)
Feedback to improve
future editions of the
standards
Integration
process
Vendors implementing
the standard
Conformity to test
applications against
the standard
Prepare the applications and tools for
integration in the utility/TSO/ISO, etc.
Applications available
to users for
integration
Conformity of the integrated
applications against
procedures defined
per business process
Integrate compliant with the standard
applications in the utility/TSO/ISO, etc.
Objectives achieved:
Integrated solutions used
in the business processes
Figure 3: The process – from requirements to ready to use application
Due to the nature of the framework provided by the IEC to develop and approve CIM international
standards, the process is relatively slow, which in turn creates a challenge related to need for timely
implementation of the CIM solutions. Therefore, utilities and policy makers need to ensure that they
support initiatives aimed at expediting the standardisation process by proposing to Standards
Development Organization (SDOs) well-tested and vetted CIM-based solutions. This will eventually
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speed up the adoption of CIM standards, their implementation and usage which will increase
efficiency in the business processes, thus maximising the added value for network operators and the
industry in general.
Normally the efforts to test conformity and perform other important steps are coordinated by a body
(association, users’ forum, project, reliability organization) in cases where there are a large number of
entities that need to exchange data in compliance with legislation or to solve a particular business
need. An example for such setup is the efforts that ENTSO-E is performing in Europe as described in
the next section.
Importance of interoperability testing to ensure vendor compliance to CIM standards
There are at least two types of efforts directly linked to interoperability testing:

Efforts to validate a CIM standard as a part of the standard’s development process;

Efforts to validate the conformity of available software solutions with an approved standard.
The interoperability testing to validate the correctness of the CIM standards started in 2000 with the
first interoperability test sponsored by EPRI and held in Las Vegas, USA. These tests were driven by
NERC requirements in North America and were focused on the CIM standards designed to exchange
common power system network models between operational systems (SCADA/EMS solutions). Later
on activities expanded to cover validation of the CIM standards related to planning and the energy
market as well as for message payloads to support system integration.
Currently in Europe, ENTSO-E plays a leading role in organising CIM interoperability tests related to
both grid model and market exchanges. Since 2009, ENTSO-E has organised five large-scale IOP
tests for grid models exchange. In 2012, ENTSO-E organised the first IOP on CIM for energy market
and began a series of IOPs related to the CIM for European market style.
In 2014, ENTSO-E launched a conformity assessment framework related to the CGMES which is an
ENTSO-E standard based on CIM and used by the ENTSO-E TSOs for operational and system
development exchanges. Using the conformity assessment framework, ENTSO-E provides services to
assess different tools developed by vendors. This is an example of an effort which targets validation
of the available application against specification of a standard. The CGMES conformity relies on
processes specified in the ISO standards on conformity assessment. Due to the complexity of a ISO
based certification process ENTSO-E decided to design the CGMES conformity more as a service
towards suppliers and ENTSO-E members rather than a full scale certification process. Only first
party assessment and second party assessment processes are applied. According to ISO the first party
assessment activity is a conformity assessment activity that is performed by the organization
(supplier) that provides the object (IT application). In such case, a Supplier would declare that his
product(s) is conforming to the specified requirements by issuing a “Declaration of Conformity”. The
second-party conformity assessment activity is performed by an organization (user) that has a user
interest in the object. In the setup applied by ENTSO-E the first parties are all vendors that would like
to conform to CGMES. ENTSO-E performs the role of a second party and issues an “Attestation of
Conformity”. This process could be applied for IEC CIM standards as well and it could be extended,
if necessary, to fully apply the ISO standards for certification where the assessment is performed by
an additional third party. ENTSO-E has already benefited from this effort by ensuring TSOs receive
better tested applications for integration into the business processes in the TSO environment.
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Conformity assessment also provides a solid base of test data for future development of the CIM
standards. Most importantly the conformity process and the implementation of the CGMES enables
roll-out of the system development studies and the implementation of the European network codes.
Figure 4 illustrates the CGMES conformity assessment process.
CGMES Conformity Assessment
CGMES
Test data
R
o
ec
mm
en
d
Opinion
formation
YES
Conformity rules and
Test procedures
CGMES Conformity Assessment Scheme documentation
NO
Recommendation
Review of the
Applications
Application
Declaration of
Conformity
Attestation
of
Conformity
Testing and checking conformity
with CGMES rules
First Party Assessment: vendor performing tests and issues a
Declaration of Conformity
Second Party Assessment: ENTSO-E evaluates the
application and issues Attestation of Conformity
Figure 4: CGMES conformity assessment process
It is important to note that the current design of the CGMES conformity assessment scheme allows
assessment of the applications only on certain CGMES functionalities that are supported by the
assessed application . Hence, declarations of conformity and attestations of conformity cannot be used
as a confirmation that an application is fully covering requirements on a specific business process.
ENTSO-E is planning to further develop the CGMES conformity assessment scheme to cover relevant
procedures and test use cases. This new development will allow assessment of the applications used
by the European TSOs against the requirements of the business processes such as day-ahead
congestion forecast, other operational planning exchanges defined in the European Network codes as
well as long term planning data exchanges.
Usage of CIM to organize and structure shared data
CIM standards have been applied in many different areas to organize and structure shared data, such
as for system integration of transmission and distribution operations and planning systems, power
system network model management and exchange needed for grid reliability system studies and
forecasts, and market operations.
One of the major strengths of the CIM is its system architecture which organizes the CIM standards
into a 3-layer framework:


Layer 1 – a normalized information model of utility operations defined using UML (Universal
Modeling Language) which defines the semantics for interoperability. This model is managed
and maintained on the Sparx Enterprise Architect (EA) platform.
Layer 2 – a set of profiles for specific system interactions/interfaces which are based on a
subset of the information model in Layer 1. These profiles define the syntax for information
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exchange, such as schemas that definer XML (Extensible Markup Language) -based message
payloads or files, but could also include schemas for data extraction from data bases.
 Layer 3 – implementation technologies for the serialization of data exchanged between
systems, applications, and devices which are also a part of the syntax definition to enable
system interoperability.
It is this layered architecture which facilitates the reuse of a single common semantic model (i.e., the
CIM) for the multitude of profiles which have been already defined as well as for future profiles yet to
be defined. Similarly since the profiles are a type of platform independent model, mappings to future
new exchange technologies are also enabled.
Another key strength of the CIM architecture is the methodology/work flow process defined to go
from a business use case to interoperable data sharing over a variety of transport mechanisms. This
methodology was developed over many years of experience with a multitude of real-world
applications at utilities and energy companies all over the world. A related benefit is the ability to
customize and extend the CIM standards as needed to meet unique data exchange requirements at a
specific utility enterprise. This topic is explained in more detail later in the section dealing with “CIM
for electrical distribution systems”.
Where CIM standards have been applied
 CIM for network models
The use of the CIM for power system network model exchange are generally based on the IEC 61970
series of standards that define the necessary CIM classes and attributes needed for different
exchanges. These standards have been improved substantially since the first implementations of IEC
61970 were launched in the USA a decade or two ago. As a consequence, these standards are today
quite mature resulting in many successful implementations world-wide. The following are just two
examples:
A. Use of CIM standards in USA (examples from ERCOTT and PJM)
The CIM standards have been used as the foundation for the integration of operational systems as part
of the Electricity Reliability Council of Texas (ERCOT) and the PJM AC2 projects.
ERCOT’s CIM based Network Model Management System (NMMS) has been operational since
2010. It uses IEC 61970 standards for the exchange of network models between participating
transmission organizations and ERCOT, as well as between different software systems within the
RTO. More details on this is provided in other articles of the magazine.
PJM AC2 project integrates several systems sourced from different vendors and legacy systems to
support common RTO workflows: Day Ahead Market Operations, Real Time Market Operations,
Reliability Operations, and Billing and Settlement. An Information Model Manager (IMM) is used to
produce and maintain power system network models in IEC 61970-452 formats for use by the
Siemens Energy Management System for reliability operations, and by the Alstom Market
Management System for market operations.
The IEC CIM was also used as the semantic model in the Siemens/PJM Shared Architecture. The
Shared Architecture provides a secure standards based integration platform with standard services and
payloads that are used by software systems provided by different, vendors and developed in house by
PJM. The system has been in continuous operation since 2011. The use of a standards based service
oriented architecture enables faster innovation in the area of the smart grid.
B. Long term planning in Europe
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As mentioned earlier, ENTSO-E has the obligation to deliver Ten Year Network Development Plans.
This along with the other drivers to have efficient data exchanges for the power system analyses lead
to the adoption of CIM for data exchanges related to long term planning studies. At that time, in 2009,
the ENTSO-E CIM data exchange was based on IEC CIM release 14 standards. Major effort was
performed to package available information, prepare the profile (the subset of CIM classes used in the
data exchange), test the standard and use it in real data exchanges.
The following table illustrates the first improvements in the processes when using CIM base data
exchange taking into account the maturity of CIM at that time and the experience of the vendors and
TSO experts in using CIM based solutions. The example is on preparation of long term planning
model for the largest synchronous zone in Europe – Regional Group Continental Europe (RG CE).
Preparation of long term planning model for RG CE
Data collection
time including data
validation process
Effort in 2007-2008
Effort in 2013
7 months (data exchange formats:
UCTE DEF, PSS/E and Excel)
2 months (data exchange standard:
CIM)
20 min in ENTSO-E Network
Modelling Database
Model assembling
3 months – significant manual process
Obtain load flow
in one tool
Model size
Nodes: 10800
Lines: 14400
Loads: 6300
Generators: 2050
Transformers: 3200
10 hours (including effort to apply
procedures due to using tools not
fit for the purpose)
Nodes: 19000
Lines: 17600
Loads: 10700
Generators: 14600
Transformers:
2-winding: 5100
3-winding: 1300
Breakers: 2100
With the use of CIM the quality of the datasets increased and TSOs were able to exchange more
detailed models to conduct studies. There is a growing expectation that the quality and the
performance of these exchanges will continue to improve even more. This was one of the reasons the
ENTSO-E CGMES specifications were developed using the newest IEC CIM release 16 related
standards. Although the processes to implement CGMES are ongoing, there is already a positive
indication that the model exchange is better. The reasons for this can be attributed to the use of a more
mature CIM standard, the CGMES conformity assessment process, the availability of good test data,
and the experience gained by experts dealing with network models exchanged using CGMES.
ENTSO-E’s TSOs are also implementing CIM for the purpose of operational planning network model
exchanges. This effort is presented in another article in the magazine.
 CIM for electrical distribution systems
A common problem for distribution utilities is that efforts to automate and manage business processes
are foiled by incongruent data from applications supporting the planning, constructing, maintaining,
and operating of power distribution and customer interface assets. As there are many tools available to
bridge the gaps between the disparate technologies, the main showstopper for large scale integration is
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that data resides in thousands of incompatible formats and cannot be systematically managed,
integrated, or cleansed.
As depicted in the following diagram (Figure 5), the IEC 61968 series is intended to facilitate interapplication integration of the various distributed software application systems supporting the
management of utility electrical distribution networks. It connects disparate applications that are
already built or new (legacy or purchased applications), each supported by dissimilar runtime
environments.
Therefore, IEC 61968 is relevant to loosely coupled applications with more
heterogeneity in languages, operating systems, protocols, and management tools.
Figure 5: Distribution management with IEC 61968 compliant interface architecture
As used in IEC 61968 series, distribution management consists of various distributed application
components for the utility to manage electrical distribution networks. These capabilities include
monitoring and control of equipment for power delivery, management processes to ensure system
reliability, voltage management, demand-side management, outage management, work management,
automated mapping and facilities management. The distribution management system could also be
integrated with premise area networks (PAN) through an advanced metering infrastructure (AMI)
network.
IEC 61968 recommends that the semantics (i.e., CIM) of system interfaces of a compliant utility interapplication infrastructure be defined using UML. The XML is a data format for structured document
interchange particularly on the Internet. One of its primary uses is information exchange between
different and potentially incompatible computer systems. Using tools available from multiple sources,
profiles are modelled in UML and then message types (XSDs) are auto-generated to define
grammar/syntax of a given interface in the utility inter-application infrastructure. Pre-defined
industry standard message types (XSDs) are available in the IEC 61968 series of standards.
However, for most enterprise integration efforts, utilities view this series of standards as a ‘starter kit’
in that they are able to use the same approach to extend the CIM to include their unique data
requirements and then generate their required message-types. For some areas such as AMI,
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customization is often not required. However, for other areas such as asset management, work
management, and customer information, it is typical that utilities have unique attributes that they want
to add on top of industry standard interfaces. While this practice is not ‘standards compliant,’ it has
served a valuable purpose - when compared with vendor-proprietary or custom-developed interfaces in that extending the industry standard saves substantial design, implementation and maintenance
costs. It also makes them more agile as business changes.
 CIM for Market
The establishment of an electricity energy market requires information to be exchanged between
electricity utilities but also a number of participants from various sectors, such as traders, power
exchanges, aggregators of information, meter data collectors, etc.
A harmonized approach was necessary to define data interchanges, to reduce the complexity and cost
of IT systems whilst ensuring the ongoing quality and usability was maintained. With this objective in
mind, the IEC 62325 series of standards were developed to facilitate efficient interactions among
market participants, market operators and system operators to provide a unified approach to
conducting market operations. Currently, two market models are being developed: one for the North
American style market (nodal market) and the other one for the European style market (zonal market).
The initial focus was on European style markets which resulted in the IEC 62325-351 standard as well
as the series of IEC 62325-451-n for dedicated business processes such as acknowledgment,
scheduling transmission capacity allocation and nomination, settlement and reconciliation, status
request and problem statement, and transparency data publication.
In particular, the IEC 62325-451-6 on transparency data publication was developed based on the
European Transparency Regulation (EU) No 543/2013 of 14 June 2013, and it is used by all the actors
that have reporting responsibilities. Development and implementation were completed within one
year thanks to the use of CIM and the IsBasedOn methodology described in IEC 62325-450.
Currently more than 100,000 messages per day are exchanged via this transparency platform.
Work is also underway for North American style markets in the form of a series of standards dealing
with Day Ahead and Intra-Day Markets. These standards describe the exchange of supplemental
market definition data and run-time market data (bids, offers, schedules of awards, and LMP prices).
Conclusion
The operation and development of bulk power systems around the world is changing rapidly due to
the need to integrate more renewables into the electricity grid, to use the assets more efficiently and to
cope with structural changes in the power system business. More analytic work needs to be performed
and this requires seamless data exchanges that meet the requirements of different business domains.
For this purpose the industry has developed, implemented, and standardized a Common Information
Model (CIM). The success stories described in this article and the ones that follow should provide
confidence that the IEC CIM standards have achieved a high level of maturity and should be deployed
as a best practice to achieve data interoperability.
For Further Reading
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[1] NIST Framework and Roadmap for Smart Grid Interoperability Standards, Release 3.0
[2] NERC - Proposal for Use of Standardized Component Models in Powerflow and Dynamics
Cases, 2013
[3] ENTSO-E Common Grid Model Exchange Standard (CGMES): https://www.entsoe.eu/majorprojects/common-information-model-cim/cim-for-grid-modelsexchange/standards/Pages/default.aspx
Biographies
Chavdar Ivanov is with ENTSO-E, Belgium
Terry Saxton is with Xtensible Solutions, USA
Jim Waight is with OMNETRIC, USA
Maurizio Monti is with RTE, France
Greg Robinson is with Xtensible Solutions, USA
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