IEC 61970-452:2015

IEC 61970-452 ®
Edition 2.0 2015-04
INTERNATIONAL
STANDARD
colour
inside
Energy management system application program interface (EMS-API) –
Part 452: CIM model exchange specification

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IEC 61970-452 ®
Edition 2.0 2015-04
INTERNATIONAL
STANDARD
colour
inside
Energy management system application program interface (EMS-API) –

Part 452: CIM model exchange specification

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.200 ISBN 978-2-8322-2580-6

– 2 – IEC 61970-452:2015 © IEC 2015
CONTENTS
FOREWORD . 6
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 11
3 Overview of data requirements . 11
3.1 Overview. 11
3.2 General requirements . 11
3.3 Transformer modeling . 12
3.4 Modeling authorities . 13
3.5 Use of measurement classes . 14
3.5.1 General . 14
3.5.2 ICCP data exchange . 15
3.6 Voltage or active power regulation . 15
3.7 Use of curves . 15
3.7.1 General . 15
3.7.2 Generating unit reactive power limits . 15
3.8 Definition of schedules . 16
4 CIM Equipment Profile . 16
4.1 CIM Equipment Profile General . 16
4.2 Concrete Classes . 16
4.2.1 Accumulator . 16
4.2.2 AccumulatorValue . 17
4.2.3 ACLineSegment . 17
4.2.4 ActivePowerLimit . 19
4.2.5 Analog . 19
4.2.6 AnalogValue . 20
4.2.7 ApparentPowerLimit . 20
4.2.8 BaseVoltage . 20
4.2.9 Bay . 21
4.2.10 Breaker. 21
4.2.11 BusbarSection . 21
4.2.12 ConformLoad . 22
4.2.13 ConformLoadGroup . 22
4.2.14 ConformLoadSchedule . 23
4.2.15 ConnectivityNode . 23
4.2.16 ControlArea . 24
4.2.17 ControlAreaGeneratingUnit . 24
4.2.18 CurrentLimit . 25
4.2.19 CurveData . 25
4.2.20 DayType . 26
4.2.21 Disconnector . 26
4.2.22 Discrete . 26
4.2.23 DiscreteValue . 27
4.2.24 EnergyConsumer . 27
4.2.25 EquivalentBranch . 28
4.2.26 EquivalentInjection . 29

4.2.27 EquivalentNetwork . 30
4.2.28 EquivalentShunt . 30
4.2.29 FossilFuel . 30
4.2.30 GeneratingUnit . 31
4.2.31 GeographicalRegion . 33
4.2.32 GrossToNetActivePowerCurve . 33
4.2.33 HydroGeneratingUnit . 34
4.2.34 HydroPump . 34
4.2.35 IEC61970CIMVersion . 35
4.2.36 Line . 35
4.2.37 LoadArea . 35
4.2.38 LoadBreakSwitch . 36
4.2.39 LoadResponseCharacteristic . 36
4.2.40 MeasurementValueSource . 38
4.2.41 MutualCoupling . 38
4.2.42 Name . 39
4.2.43 NameType . 40
4.2.44 NonConformLoad. 40
4.2.45 NonConformLoadGroup . 41
4.2.46 NonConformLoadSchedule . 41
4.2.47 NuclearGeneratingUnit . 42
4.2.48 OperationalLimitSet . 42
4.2.49 OperationalLimitType . 43
4.2.50 PhaseTapChangerAsymetrical . 43
4.2.51 PhaseTapChangerLinear . 44
4.2.52 PhaseTapChangerSymetrical . 45
4.2.53 PhaseTapChangerTabular . 46
4.2.54 PhaseTapChangerTabularPoint . 46
4.2.55 PowerTransformer . 48
4.2.56 PowerTransformerEnd . 48
4.2.57 RatioTapChanger . 50
4.2.58 RatioTapChangerTabular . 51
4.2.59 RatioTapChangerTabularPoint . 51
4.2.60 ReactiveCapabilityCurve . 52
4.2.61 RegularTimePoint . 53
4.2.62 RegulatingControl . 54
4.2.63 RegulationSchedule . 55
4.2.64 Season . 56
4.2.65 SeriesCompensator . 56
4.2.66 ShuntCompensator . 56
4.2.67 StaticVarCompensator . 57
4.2.68 StationSupply . 58
4.2.69 SubGeographicalRegion . 59
4.2.70 SubLoadArea . 59
4.2.71 Substation . 59
4.2.72 Switch . 60
4.2.73 SwitchSchedule . 60
4.2.74 SynchronousMachine. 61
4.2.75 TapChangerControl . 63

– 4 – IEC 61970-452:2015 © IEC 2015
4.2.76 TapSchedule . 63
4.2.77 Terminal . 64
4.2.78 ThermalGeneratingUnit . 64
4.2.79 TieFlow. 65
4.2.80 VoltageLevel . 65
4.2.81 VoltageLimit . 66
4.2.82 WindGeneratingUnit . 66
4.3 Abstract Classes . 67
4.3.1 BasicIntervalSchedule . 67
4.3.2 ConductingEquipment . 67
4.3.3 Conductor . 68
4.3.4 ConnectivityNodeContainer . 68
4.3.5 Curve . 68
4.3.6 EnergyArea . 69
4.3.7 Equipment . 69
4.3.8 EquipmentContainer . 70
4.3.9 EquivalentEquipment . 70
4.3.10 IdentifiedObject . 70
4.3.11 LoadGroup . 71
4.3.12 Measurement . 71
4.3.13 MeasurementValue . 72
4.3.14 OperationalLimit . 73
4.3.15 PhaseTapChanger . 73
4.3.16 PhaseTapChangerNonLinear . 73
4.3.17 PowerSystemResource . 74
4.3.18 RegularIntervalSchedule . 74
4.3.19 RegulatingCondEq . 75
4.3.20 RotatingMachine . 75
4.3.21 SeasonDayTypeSchedule . 76
4.3.22 TapChanger. 76
4.3.23 TransformerEnd . 77
4.4 Enumerations . 78
4.4.1 ControlAreaTypeKind . 78
4.4.2 CurveStyle . 78
4.4.3 FuelType . 79
4.4.4 GeneratorControlSource . 79
4.4.5 OperationalLimitDirectionKind. 79
4.4.6 RegulatingControlModeKind . 80
4.4.7 SeasonName . 80
4.4.8 SVCControlMode . 80
4.4.9 SynchronousMachineOperatingMode . 80
4.4.10 SynchronousMachineType . 81
4.4.11 TapChangerKind . 81
4.4.12 TransformerControlMode . 81
4.4.13 UnitSymbol . 81
4.4.14 WindingConnection . 82
4.5 Datatypes . 82
4.5.1 ActivePower . 82
4.5.2 AngleDegrees . 82

4.5.3 ApparentPower . 82
4.5.4 Conductance . 83
4.5.5 CurrentFlow . 83
4.5.6 Length . 83
4.5.7 Money . 83
4.5.8 PerCent . 83
4.5.9 Reactance . 84
4.5.10 ReactivePower . 84
4.5.11 Resistance . 84
4.5.12 Seconds . 84
4.5.13 Susceptance . 84
4.5.14 Voltage . 84
4.5.15 VoltagePerReactivePower . 85
5 Amplifications and conventions . 85
5.1 Overview. 85
5.2 XML file validity . 85
5.3 Normative string tables . 85
5.4 Roles and multiplicity . 86
Annex A (informative) Model exchange use cases . 87
Annex B (informative) Modeling authorities . 91
Annex C (informative) Common power system model (CPSM) minimum data
requirements . 93
Bibliography . 99

Figure 1 – Two winding transformer impedance . 12
Figure 2 – Three winding transformer impedance . 13
Figure A.1 – Security coordinators . 87
Figure A.2 – CIM model exchange . 88
Figure A.3 – Revised CIM model exchange . 89
Figure A.4 – Hierarchical modeling . 90

Table 1 – Valid measurementTypes . 14
Table 2 – Profiles defined in this document . 16
Table 3 – Valid attribute values . 85

– 6 – IEC 61970-452:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENERGY MANAGEMENT SYSTEM APPLICATION
PROGRAM INTERFACE (EMS-API) –
Part 452: CIM model exchange specification

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The present part of International Standard IEC 61970 has been prepared by IEC technical
committee 57: Power systems management and associated information exchange.
This second edition cancels and replaces the first edition published in 2013. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) subclause 3.3, Transformer modeling – Updated description of transformer modelling to
reflect changes in the modelling of transformers to work for both transmission and
distribution systems;
b) subclause 3.5.1, Use of measurement classes – General – Updated to reflect changes to
the measurement model;
c) subclause 3.5.2, ICCP data exchange – Updated to reflect changes to the use of
identification in the model (IdentifiedObject, Name, and NameType);
d) the following detailed changes were made to Clause 4, CIM Equipment Profile:
• Added Measurement.unitMultiplier and Measurement.unitSymbol to replace
association to class Unit.
• Added PowerTransformerEnd to replace TransformerWinding.
• Made PhaseTapChanger not concrete (abstract) and added
PhaseTapChangerNonLinear (also not concrete), PhaseTapChangerSymetrical,
PhaseTapChangerAsymetrical, and PhaseTapChangerLinear.
• Added PhaseTapChanger.TransformerEnd to replace
PhaseTapChanger.TransformerWinding.
• Added RatioTapChanger.TransformerEnd to replace
RatioTapChanger.TransformerWinding.
• Added TapChangerControl class to replace direct link TapChanger.RegulatingControl.
• Added RatioTapChanger.stepVoltageIncrement to replace
TapChanger.stepVoltageIncrement.
• Added PhaseTapChangerTabular, PhaseTapChangerTabularPoint,
RatioTapChangerTabular, and RatioTapChangerTabularPoint to replace
ImpedanceVariationCurve, PhaseVariationCurve, and RatioVariationCurve.
• Added Switch.ratedCurrent as optional attribute.
• Changed all attributes of LoadResponseCharacteristic to optional except for
exponentModel.
• Changed CurveData.y2Value to optional.
• Added PowerTransformer.vectorGroup as optional attribute.
• Added note to OperationalLimitSet stating that “Either an association to Equipment or
an association to Terminal must be supplied, but not both.”
• Added SeriesCompensator.r0 and x0 as optional attributes.
• Added attributes for PhaseTapChangerTabularPoint and
RatioTapChangerTabularPoint.
• Added RotatingMachine to the profile so that ratedS can be inherited by
SynchronousMachine as an optional attribute.
• Changed association between RegulatingCondEq and RegulatingControl to be
optional.
• Made OperationalLimitType attributes direction and acceptableDuration optional.
• Added classes Name and NameType to profile.
• Removed PowerTransformer.vectorGroup from the profile.
• Added PowerTransformerEnd.phaseAngleClock as an optional attribute.
• Made attributes RegulatingControl.targetRange and targetValue optional and added a
note stating that they are not required if a RegulationSchedule is provided.
• Added TransformerEnd.endNumber to the profile for use with
PowerTransformerEnd.phaseAngleClock.
• Added association OperationalLimt.OperationalLimitSet.
• Added association Name.IdentifiedObject.
• Updated PowerTransformer profile description to also refer to Terminals.
• Changed reference to association RegulatingControl.RegulationSchedule to use
RegulationSchedule.RegulatingControl instead.

– 8 – IEC 61970-452:2015 © IEC 2015
• Changed TapChanger attributes highStep, lowStep, neutralStep and normalStep to
optional, because they are not required if the ltcFlag is false.
• Changed BasicIntervalSchedule.value2Unit and RegularTimePoint.value2 to optional,
because they are not required for RegulationSchedule, TapSchedule or
SwitchSchedule.
• Changed Analog.positiveFlowIn to be optional, because not all analogs have a flow
direction (voltage, for instance).
• Added PowerTransformerEnd.g as optional attribute.
• Added SynchronousMachine.referencePriority as optional attribute.
• Added profile description for AccumulatorValue, AnalogValue, and DiscreteValue
explaining that the classes are only used to define measurements available via ICCP,
not to supply values for those measurements.
• Added attribute Switch.retained as required.
• Added association TransformerEnd.BaseVoltage as optional.
• Made association ControlArea.energyArea optional.
The text of this standard is based on the following documents:
CDV Report on voting
57/1451/CDV 57/1503/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61970 series, published under the general title Energy
management system application program interface (EMS-API), can be found on the IEC
website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
This standard is one of the IEC 61970 series that define an application program interface
(API) for an energy management system (EMS).
The IEC 61970-3x series of documents specify a Common Information Model (CIM). The CIM
is an abstract model that represents all of the major objects in an electric utility enterprise
typically needed to model the operational aspects of a utility. It provides the semantics for the
IEC 61970 APIs specified in the IEC 61970-4x series of Component Interface Standards
(CIS). The IEC 61970-3x series includes IEC 61970-301, Common Information Model (CIM)
base and draft standard IEC 61970-302, Common Information Model (CIM) Financial,
EnergyScheduling and Reservations.
This standard is one of the IEC 61970-4x series of Compoment Interface Standards that
specify the functional requirements for interfaces that a component (or application) shall
implement to exchange information with other components (or applications) and/or to access
publicly available data in a standard way. The component interfaces describe the specific
message contents and services that can be used by applications for this purpose. The
implementation of these messages in a particular technology is described in IEC 61970-5.
This part of IEC 61970 specifies the specific profiles (or subsets) of the CIM for exchange of
static power system data between utilities, security coordinators and other entities
participating in a interconnected power system, such that all parties have access to the
modeling of their neighbor’s systems that is necessary to execute state estimation or power
flow applications. Currently only one profile, the Equipment Profile, has been defined. A
companion standard, IEC 61970-552, defines the CIM XML Model Exchange Format based on
the Resource Description Framework (RDF) Schema specification language which is
recommended to be used to transfer power system model data for the IEC 61970-452 profile.

– 10 – IEC 61970-452:2015 © IEC 2015
ENERGY MANAGEMENT SYSTEM APPLICATION
PROGRAM INTERFACE (EMS-API) –
Part 452: CIM model exchange specification

1 Scope
This part of IEC 61970 is a member of the IEC 61970-450 to -499 series that, taken as a
whole, defines at an abstract level the content and exchange mechanisms used for data
transmitted between control centers and/or control center components.
The purpose of this document is to rigorously define the subset of classes, class attributes,
and roles from the CIM necessary to execute state estimation and power flow applications.
The North American Electric Reliability Council (NERC) Data Exchange Working Group
(DEWG) Common Power System Modeling group (CPSM) produced the original data
requirements, which are shown in Annex C. These requirements are based on prior industry
practices for exchanging power system model data for use primarily in planning studies.
However, the list of required data has been extended to facilitate a model exchange that
includes parameters common to breaker-oriented applications. Where necessary this
document establishes conventions, shown in Clause 5, with which an XML data file must
comply in order to be considered valid for exchange of models.
This document is intended for two distinct audiences, data producers and data recipients, and
may be read from two perspectives.
From the standpoint of model export software used by a data producer, the document
describes a minimum subset of CIM classes, attributes, and associations which must be
present in an XML formatted data file for model exchange. This standard does not dictate how
the network is modelled, however. It only dictates what classes, attributes, and associations
are to be used to describe the source model as it exists. All classes, attributes, and
associations not explicitly labeled as recommended or conditionally required should be
considered required with the following caveat. Consider, as an example, the situation in which
an exporter produces an XML data file describing a small section of the exporter’s network
that happens to contain no breakers. The resulting XML data file should, therefore, not
contain an instance of the Breaker class. On the other hand, if the section of the exporter’s
network does contain breakers, the resulting data file should contain instances of the Breaker
class that include, at a minimum, the attributes and roles described herein for Breakers.
Furthermore, it should be noted that an exporter may, at his or her discretion, produce an
XML data file containing additional class data described by the CIM RDF Schema but not
required by this document provided these data adhere to the conventions established in
Clause 5.
From the standpoint of the model import used by a data recipient, the document describes a
subset of the CIM that importing software must be able to interpret in order to import exported
models. As mentioned above, data providers are free to exceed the minimum requirements
described herein as long as their resulting data files are compliant with the CIM RDF Schema
and the conventions established in Clause 5. The document, therefore, describes additional
classes and class data that, although not required, exporters will, in all likelihood, choose to
include in their data files. The additional classes and data are labeled as recommended or as
not required to distinguish them from their required counterparts. Please note, however, that
data importers could potentially receive data containing instances of any and all classes
described by the CIM RDF Schema.

2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
NOTE For general glossary definitions, see IEC 60050, International Electrotechnical Vocabulary.
IEC 61970-301:2013, Energy management system application program interface (EMS-API) –
Part 301: Common information model (CIM) base
IEC 61970-501, Energy management system application program interface (EMS-API) –
Part 501: Common Information Model Resource Description Framework (CIM RDF) schema
3 Overview of data requirements
3.1 Overview
An extensive discussion of the model exchange use cases can be found in Annex A. In all
cases, the purpose of this standard is:
• To improve the accuracy of power system models used in critical systems, particularly
the representation of parts of the network outside the primary domain of the system in
question.
• To achieve consistency among the models used by the various systems that play a
role in operating or planning the interconnection.
• To reduce the overall cost of maintaining critical models used in operating or planning
an interconnection.
The classes, attributes, and associations identified in this document represent the minimum
subset of the full CIM model necessary to exchange sufficient power system data to support
state estimation and power flow.
3.2 General requirements
The following requirements are general in nature or involve multiple classes. Additional
requirements are defined in the sections for the individual classes.
– The cardinality defined in the CIM model shall be followed, unless a different cardinality is
explicitly defined in this document. For instance, the cardinality on the association
between VoltageLevel and BaseVoltage indicates that a VoltageLevel shall be associated
with one and only one BaseVoltage, but a BaseVoltage can be associated with zero to
many VoltageLevels.
– Associations between classes referenced in this document and classes not referenced
here are not required regardless of cardinality. For instance, the CIM requires that a
HydroGeneratingUnit be associated with a HydroPowerPlant. Because the
HydroPowerPlant class is not included in this document the association to
HydroPowerPlant is not considered mandatory in this context.
– The attribute “name” inherited by many classes from the abstract class IdentifiedObject is
not required to be unique. The RDF ID defined in the data exchange format is the only
unique and persistent identifier used for this data exchange. The attribute
IdentifiedObject.name is, however, always required. The additional attribute of
IdentifiedObject, aliasName, is not required.
– Although not defined within this profile, the IdentifiedObject.mRID attribute should be used
as the RDF ID. The RDF ID can not begin with a number. An underscore should be added
as the first character if necessary. The RDF ID shall be globally unique. A prefix may be

– 12 – IEC 61970-452:2015 © IEC 2015
added, if necessary, to ensure global uniqueness, but the RDF ID including the prefix shall
be within the maximum character limit specified below.
– The maximum character length of names and identifiers are listed below.
• rdf:ID – 60 characters maximum
• IdentifiedObject.name – 32 characters maximum
• IdentifiedObject.aliasname – 40 characters maximum
– To maintain a consistent naming hierarchy, each Substation shall be contained by a
SubGeographicalRegion and each SubGeographicalRegion shall be contained by one and
only one GeographicalRegion.
– Equipment defined without connectivity, because the associated Terminal(s) are not
connected to ConnectivityNodes is allowed, for instance a ShuntCompensator whose
Terminal is not associated to a ConnectivityNode.
– UTF-8 is the standard for file encoding. UTF-16 is not supported.
– Instance data to be exchanged shall make use of the most detailed class possible. The
classes GeneratingUnit, Switch, and EnergyConsumer should only be used if the
information to determine the more detailed class (ThermalGeneratingUnit,
HydroGeneratingUnit, Breaker, Disconnector, etc.) is not available.
3.3 Transformer modeling
A two winding PowerTransformer has two PowerTransformerEnds. This gives the option to
specify the impedance values for the equivalent pi-model completely at one end or split them
between the two ends. The impedances shall be specified at the primary voltage
...