IEC 61400-25-1:2006

INTERNATIONAL IEC
STANDARD 61400-25-1
First edition
2006-12
Wind turbines –
Part 25-1:
Communications for monitoring
and control of wind power plants –
Overall description of principles and models
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INTERNATIONAL IEC
STANDARD 61400-25-1
First edition
2006-12
Wind turbines –
Part 25-1:
Communications for monitoring
and control of wind power plants –
Overall description of principles and models
© IEC 2006 ⎯ Copyright - all rights reserved
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– 2 – 61400-25-1 © IEC:2006(E)
CONTENTS
FOREWORD.3
INTRODUCTION.5

1 Scope.7
2 Normative references .8
3 Terms and definitions .9
4 Abbreviated terms .13
5 Overall description of the IEC 61400-25 series .13
5.1 General .13
5.2 Top-down view on wind power plants .14
5.3 Generic requirements on communication.15
5.4 Communication model of the IEC 61400-25 series.17
6 Wind power plant information model .20
6.1 General .20
6.2 Information modelling methodology .20
7 Wind power plant information exchange model .24
7.1 General .24
7.2 Information exchange modelling methodology .24
8 Mapping to communication protocols .30
8.1 General .30
8.2 Architecture of the mappings .31
8.3 Mapping of the wind power plant information model .31

Figure 1 – Conceptual communication model of the IEC 61400-25 series .8
Figure 2 – Data processing by the server (conceptual).18
Figure 3 – Modelling approach (conceptual).19
Figure 4 – Structure of wind power plant information model .22
Figure 5 – Client and server role.24
Figure 6 – IEM Service models .25
Figure 7 – Conceptual information exchange model for a wind power plant.26
Figure 8 – IEM service model with examples.28
Figure 9 – Sequence diagram .29
Figure 10 – ACSI mapping to communication stacks/profiles.30
Figure 11 – Communication profiles.31

Table 1 – Operational functions .16
Table 2 – Management functions .17
Table 3 – Wind power plant information categories .21
Table 4 – General table structure of a logical node (LN) .23
Table 5 – Data class attributes in a logical node .23
Table 6 – Service table .28

61400-25-1 © IEC:2006(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
WIND TURBINES –
Part 25-1: Communications for monitoring
and control of wind power plants –
Overall description of principles and models

FOREWORD
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61400-25-1 has been prepared by IEC technical committee 88:
Wind turbines.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The text of this standard is based on the following documents:
FDIS Report on voting
88/274/FDIS 88/280/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
A list of all parts of the IEC 61400 series, under the general title Wind turbines can be found
on the IEC website.
– 4 – 61400-25-1 © IEC:2006(E)

The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.

61400-25-1 © IEC:2006(E) – 5 –
INTRODUCTION
The IEC 61400-25 series addresses vendors (manufacturers, suppliers), operators, owners,
planners, and designers of wind power plants as well as system integrators and utility
companies operating in the wind energy market. The IEC 61400-25 series is intended to be
accepted and to be used world-wide as the international standard for communications in the
domain of wind power plants.
The IEC 61400-25 series has been developed in order to provide a uniform communications
basis for the monitoring and control of wind power plants. It defines wind power plant specific
information, the mechanisms for information exchange and the mapping to communication
protocols. In this regard, the IEC 61400-25 series defines details required to exchange the
available information with wind power plant components in a manufacturer-independent
environment. This is done by definitions made in this part of the IEC 61400-25 series or by
reference to other standards.
The wind power plant specific information describes the crucial and common process and
configuration information. The information is hierarchically structured and covers for example
common information found in the rotor, generator, converter, grid connection and the like. The
information may be simple data (including timestamp and quality) and configuration values or
more comprehensive attributes and descriptive information, for example engineering unit,
scale, description, reference, statistical or historical information. All information of a wind
power plant defined in the IEC 61400-25 series is name tagged. A concise meaning of each
data is given. The standardised wind power plant information can be extended by means of a
name space extension rule. All data, attributes and descriptive information can be exchanged
by corresponding services.
The implementation of the IEC 61400-25 series allows SCADA systems (supervisory control
and data acquisition) to communicate with wind turbines from multiple vendors. The
standardised self-description (contained either in a XML file or retrieved online from a device)
can be used to configure SCADA applications. Standardisation of SCADA applications are
excluded in the IEC 61400-25 series but standardised common wind turbine information
provides means for re-use of applications and operator screens for wind turbines from
different vendors. From a utility perspective unified definitions of common data minimise
conversion and re-calculation of data values for evaluation and comparison of all their wind
power plants.
The IEC 61400-25 series can be applied to any wind power plant operation concept, i.e. both
individual wind turbines, clusters and more integrated groups of wind turbines. The application
area of the IEC 61400-25 series covers components required for the operation of wind power
plants, i.e. not only the wind turbine generator, but also the meteorological system, the
electrical system, and the wind power plant management system. The wind power plant
specific information in the IEC 61400-25 series excludes information associated with feeders
and substations. Substation communication is covered within the IEC 61850 series of
standards.
The intention of the IEC 61400-25 series is to enable components from different vendors to
communicate with other components, at any location. Object-oriented data structures can
make the engineering and handling of large amounts of information provided by wind power
The IEC 61400-25 series supports scalability,
plants less time-consuming and more efficient.
connectivity, and interoperability.
The IEC 61400-25 series is a basis for simplifying the contracting of the roles the wind turbine
and SCADA systems have to play. The crucial part of the wind power plant information, the
information exchange methods, and the communication stacks are standardised. They build a
basis to which procurement specifications and contracts could easily refer.
The IEC 61400-25 series is organised in several parts. IEC 61400-25-1 offers an introductory
orientation, crucial requirements, and a modelling guide.

– 6 – 61400-25-1 © IEC:2006(E)
NOTE 1 Performance of the IEC 61400-25 series implementations are application specific. The IEC 61400-25
series does not guarantee a certain level of performance. This is beyond the scope of the IEC 61400-25 series.
However, there is no underlying limitation in the communications technology to prevent high speed application
(millisecond level responses).
NOTE 2 IEC 61400-25-4 is, at the time of the publication of IEC 61400-25-1 (this part), still to be published. With
IEC 61400-25-4 the mapping of the information and information exchange models to a specific communication
profile will be described/defined in detail. IEC 61400-25-4 may consist of more than one normative mapping but at
least one of the optional mappings has to be selected in order to be in conformance with the IEC 61400-25 series.
IEC 61400-25-4 is expected to include the following mappings:
Webservices
IEC 61850-8-1 MMS
OPC XML DA
IEC 60870-5-104
DNP3
Each of the different mappings specifies individually which and how information models (IEC 61400-25-2) and
information exchange models (IEC 61400-25-3) will be supported. The mapping will only reflect the information
model and the information exchange services given in IEC 61400-25-2 and IEC 61400-25-3. The individual
selected mapping will as a minimum support the mandatory data and data attributes, and the associated services.
A specific mapping may, for implementation reasons or due to underlying properties of the communication protocol
used, need to extend and clarify individual information or individual services in IEC 61400-25-2 and
IEC 61400-25-3. IEC 61400-25-4 will in this sense have the highest priority of the ranking order in regards of
implementation.
61400-25-1 © IEC:2006(E) – 7 –

WIND TURBINES –
Part 25-1: Communications for monitoring
and control of wind power plants –
Overall description of principles and models

1 Scope
The focus of the IEC 61400-25 series is on the communications between wind power plant
components such as wind turbines and actors such as SCADA Systems. Internal
communication within wind power plant components is beyond the scope of the IEC 61400-25
series.
The IEC 61400-25 series is designed for a communication environment supported by a client-
server model. Three areas are defined, that are modelled separately to ensure the scalability
of implementations:
1) wind power plant information models,
2) information exchange model, and
3) mapping of these two models to a standard communication profile.
The wind power plant information model and the information exchange model, viewed
together, constitute an interface between client and server. In this conjunction, the wind
power plant information model serves as an interpretation frame for accessible wind power
plant data. The wind power plant information model is used by the server to offer the client a
uniform, component-oriented view of the wind power plant data. The information exchange
model reflects the whole active functionality of the server. The IEC 61400-25 series enables
connectivity between a heterogeneous combination of client and servers from different
manufacturers and suppliers.
As depicted in Figure 1, the IEC 61400-25 series defines a server with the following aspects:
– information provided by a wind power plant component, for example, ‘wind turbine rotor
speed’ or ‘total power production of a certain time interval’ is modelled and made available
for access. The information modelled in the IEC 61400-25 series is defined in IEC 61400-
25-2.
– services to exchange values of the modelled information defined in IEC 61400-25-3.
– mapping to a communication profile, providing a protocol stack to carry the exchanged
values from the modelled information (IEC 61400-25-4).
The IEC 61400-25 series only defines how to model the information, information exchange
and mapping to specific communication protocols. The IEC 61400-25 series excludes a
definition of how and where to implement the communication interface, the application
program interface and implementation recommendations. However, the objective of the IEC
61400-25 series is that the information associated with a single wind power plant component
(such as a wind turbine) is accessible through a corresponding logical device.
IEC 61400-25-1 gives an overall description of the principles and models used in the
IEC 61400-25 series of standards.
NOTE The IEC 61400-25 series focuses on the common, non-vendor-specific information. Those information
items that tend to vary greatly between vendor-specific implementations can for example be specified in bilateral
agreements, in user groups, or in amendments to the IEC 61400-25 series.

– 8 – 61400-25-1 © IEC:2006(E)
Communication model of the IEC 61400-25 series
Client Server
Messaging
Messaging
Information exchange Information exchange
Information exchange through mapping Information exchange
through mapping
model (get, set, report, model (get, set, report,
model (get, set, report, to communication model (get, set, report,
to communication
log, control, publish / log, control, publish /
log, control, publish / profile (Read, log, control, publish /
profile (Read,
subscribe, etc.) subscribe, etc.)
subscribe, etc.) write, . message) subscribe, etc.)
write, . message)
defined in defined in
defined in defined in defined in
defined in
Wind power
Actor IEC 61400-25-3 IEC 61400-25-3
IEC 61400-25-3 IEC 61400-25-4 IEC 61400-25-3
plant
e.g. IEC 61400-25-4
component
SCADA
e.g. wind turbine
Wind power plant Wind power plant
Wind power plant Wind power plant
information model information model
information model information model
(rotor speed, break
defined in
(rotor speed, break
defined in
status, total power
status, total power
IEC 61400-25-2
Application Application
IEC 61400-25-2 production, etc.)
production, etc.)
defined in
defined in
IEC 61400-25-2
IEC 61400-25-2
Outside
Outside
scope
scope
IEC  2143/06
Figure 1 – Conceptual communication model of the IEC 61400-25 series
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 61400-12-1, Wind turbines – Part 12-1: Power performance measurements of electricity
producing wind turbines
IEC 61400-25 (all parts), Wind turbines – Part 25: Communications for monitoring and control
of wind power plants
IEC 61850-7-1:2003, Communication networks and systems in substations – Part 7-1: Basic
communication structure for substation and feeder equipment – Principles and models
IEC 61850-7-2:2003, Communication networks and systems in substations – Part 7-2: Basic
communication structure for substation and feeder equipment – Abstract communication
service interface (ACSI)
IEC 61850-7-3:2003, Communication networks and systems in substations – Part 7-3: Basic
communication structure for substation and feeder equipment – Common data classes
IEC 61850-7-4:2003, Communication networks and systems in substations – Part 7-4: Basic
communication structure for substation and feeder equipment – Compatible logical node
classes and data classes
IEC 61850-8-1:2004, Communication networks and systems in substations – Part 8-1:
Specific Communication Service Mapping (SCSM) – Mappings to MMS (ISO 9506-1 and ISO
9506-2) and to ISO/IEC 8802-3
ISO 7498-1:1994, Information technology – Open Systems Interconnection – Basic Reference
Model: The Basic Model
61400-25-1 © IEC:2006(E) – 9 –
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
3.1
actor
role a system plays in the context of monitoring and control, while it is not directly involved in
wind power plant operation, such as Supervisory Control and Data Acquisition System
(SCADA)
NOTE There are many other designations for example Central Management System, Monitoring and Control
System, Remote Control System
3.2
alarm
wind power plant state information. Statement of safety intervention by the wind turbine
control system (i.e. on/off)
3.3
characteristic values
properties of analogue information (min, max, avg, dev, etc.)
3.4
command
controllable data for system behaviour (enable/disable, active/deactivate, etc.)
3.5
communication function
used by an actor to configure, perform and monitor the information exchange with wind power
plants, for example operational and management function
3.6
control
operational function used for changing and modifying, intervening, switching, controlling,
parameterisation and optimising of wind power plants
3.7
counting value
total number of occurrences of a specific event
3.8
data retrieval
operational function used for collecting of wind power plant data
3.9
diagnostics
management function used to set up and provide for self-monitoring of the communication
system
3.10
electrical system
component of a wind power plant responsible for collecting and transmitting the energy
produced in wind turbines
3.11
event
state transition (status, alarm, command)

– 10 – 61400-25-1 © IEC:2006(E)
3.12
Intelligent Electronic Device
IED
any device incorporating one or more processors, with the capability to receive data from an
external sender or to send data to an external receiver
NOTE For example wind turbine controller. An IED may have connections as a client, or as a server, or both, with
other IED.
3.13
information
content of communication. The basic element is raw data from the wind power plant
component, which shall be processed into specified information according to the IEC 61400-
25 series. Wind power plant information categories: source information (analogue and state
information), derived information (statistical and historical information). Information is defined
as data (usually processed and derived data, and information describing other data)
3.14
information exchange
communication process between two systems, such as wind power component and actor, with
the goal to provide and to get relevant information. Requires specific communication
functions, consisting of one or more services
3.15
information model
knowledge concerning functions and devices in which the functions are implemented
NOTE This knowledge is made visible and accessible through the means of the IEC 61400-25 series. The model
describes in an abstract way a communication oriented representation of a real function or device.
3.16
log
wind power plant historical information. Chronological list of source information for a period of
time
3.17
logging
operational function. The praxis of recording sequential data often chronologically. The result
of the logging is a log
3.18
logical device
entity that represent a set of typical wind power plant functions
3.19
management function
required for the administration of the information exchange in a certain level. Management
functions are user/access management, time synchronisation, diagnostics, and configuration
3.20
mandatory
defined content shall be provided in compliance to the IEC 61400-25 series
3.21
measured data
sampled value of a process quantity with associated data attributes such as time stamp and
quality
61400-25-1 © IEC:2006(E) – 11 –
3.22
meteorological system
component of a wind power plant responsible for the monitoring of the ambient conditions, for
example the wind speed, wind direction, pressure, temperature etc. It supplies data for
various purposes for example to correlate the meteorological data to the electrical energy
output by individual wind turbines to the potentially usable wind energy
3.23
monitoring
operational function used for local or remote observation of a system or a process for any
changes which may occur over time. The term can also be used for observation of the
behaviour of a data value or a group of data values
3.24
operational function
function to obtain information and to send instructions for the normal daily operation of wind
power plants. Types: monitoring, logging, reporting, data retrieval, control
3.25
optional
defined content can be optionally provided in compliance with the IEC 61400-25 series
3.26
parameter
controllable information intended for obtaining or correcting a system behaviour
3.27
processed data
measured value, with the associated data attributes such as time stamp and quality, which
has been processed according the calculation method attribute
3.28
profile(s)
format(s) used by a particular protocol to transmit data objects or commands, etc.
3.29
protocol stack
particular software implementation of a computer networking protocol suite. The terms are
often used interchangeably. Strictly speaking, the suite is the definition of the protocols and
the stack is the software implementation of them
3.30
report
actual information send by the function reporting. A report can contain all kinds of information
defined in IEC 61400-25-2
3.31
reporting
operational function to transfer data from a server to a client, initiated by a server application
process
3.32
Supervisory Control and Data Acquisition
SCADA
system based on a processor unit which receives information from IEDs, determines the
control requirements and sends commands to IEDs. A computer system that for example
dispatchers use to monitor the power distribution throughout a service or control area

– 12 – 61400-25-1 © IEC:2006(E)
3.33
status
state condition of a component or system (st1/st2/.stn)
3.34
statistical information
result of applying a statistical algorithm to a set of data in order to get minimum, maximum,
mean standard deviation, etc.
3.35
timing data
time duration of a specific state
3.36
time synchronisation
synchronization is the coordination of occurrences to operate in unison with respect to time.
This process can be a premeditated arrangement set forth on a parallel time scape, or it can
be an observable coincidence in eventuality
3.37
three phase data
measured value in a three phase electrical circuit with associated data attributes such as time
stamp, quality and calculation method
3.38
transient log
event triggered chronological list of high resolution information for a short period of time
(event driven report)
3.39
user/access management
management function used for setting up, modifying, deleting users (administratively),
assigning access rights (administratively) and monitoring access
NOTE A management function does not necessarily include communication services.
3.40
wind power plant
complete system consisting of any number of technical subsystems referred to in the IEC
61400-25 series as wind power plant components, for example one or more wind turbines
NOTE The main objective of a wind power plant is to generate electrical energy from the wind.
3.41
wind power plant analogue information
continuous information concerning the actual condition or behaviour of a component or
system
NOTE Types are, for example, measured value, processed value, three phase value, setpoint, parameter.
3.42
wind power plant component
technical system employed in the operation of wind power plants, such as wind turbine,
meteorological, electrical and wind power plant management system
3.43
wind power plant management system
component of a wind power plant, which is responsible to ensure that the complete system
adapts itself to the static and dynamic conditions and requirements of the electrical power
connection (i.e., interoperation of the WTs with substation and other power network related
devices)
61400-25-1 © IEC:2006(E) – 13 –
NOTE A wind power plant management system may include other functions (e.g. Shadow control functionality,
noise or sound reduction, ice warning, Lightning protection) not modelled in the IEC 61400-25 series.
3.44
wind turbine
main component of a wind power plant. It is responsible for generating energy and meets the
task of using the wind potential of a certain location that converts kinetic wind energy into
electric energy
4 Abbreviated terms
ACSI Abstract Communication Service Interface (defined e.g. in IEC 61850-7-2)
CDC Common Data Class
DC Data Class
DNP3 Distributed Network Protocol version 3
IED Intelligent Electronic Device
IEM Information Exchange Model
LCB Log Control Block
LD Logical Device
LN Logical Node
O&M Operation and maintenance
OSI Open Systems Interconnection
RCB Report Control Block
SCADA Supervisory Control and Data Acquisition
SCSM Specific Communication Service Mapping (defined e.g. in IEC 61850-8-1)
WPP Wind Power Plant
WT Wind Turbine
XML Extensible Mark-up Language

5 Overall description of the IEC 61400-25 series
5.1 General
The main objective of the IEC 61400-25 series is to create a standard basis for manufacturer-
independent communications for monitoring and control. Manufacturers and suppliers of wind
power plant components shall implement the IEC 61400-25 series in their devices and
systems.
Clause 5 provides a general overview of the context, models, modelling approach, and
application possibilities of the IEC 61400-25 series.
Subclause 5.2 provides a top-down view on wind power plants and shows the areas where the
IEC 61400-25 series can be applied. It explains what is to be understood under the term ‘wind
power plant’, which operation concepts are distinguished and which components are used to
run wind power plants.
Subclause 5.3 describes the demands made with reference to the communication taking place
within the framework of the monitoring and control of wind power plants. It explains which
general communication capabilities wind power plants shall possess and which contents and
functions are required for communication.

– 14 – 61400-25-1 © IEC:2006(E)
Subclause 5.4 provides an overview of the communication model defined by the IEC 61400-
25 series. The server-client communication environment that served as the basis when
developing the IEC 61400-25 series is introduced briefly. Next, three server-client application
topologies are introduced, illustrating the communication architectures that are possible by
way of an example. Finally, the three areas defined by the IEC 61400-25 series to be
implemented as the standard for the monitoring and control of wind power plants will be
introduced on a generally understandable level.
5.2 Top-down view on wind power plants
5.2.1 Definition of wind power plants
Wind power plants constitute complete systems consisting of any number of technical
subsystems with clearly separated tasks. The subsystems are referred to in the further
discourse as wind power plant components and will be described in 5.2.2.
5.2.2 Wind power plant components
Wind power plant components are technical systems employed in the operation of wind power
plants. They consist of various sub-components, which will not be differentiated in the
following. All wind power plant components fall within the application area of the IEC 61400-
25 series.
The information modelled in the IEC 61400-25 series covers the following corresponding
components:
Wind turbine
− rotor,
− transmission,
− generator,
− converter,
− nacelle,
− yaw system,
− tower,
− alarm system.
Meteorological system
− meteorological conditions of the wind power plant.
Wind power plant management system
− wind power plant control.
Electrical system
− wind power plant grid connection.
The wind turbine (with its many sub-components) is the main component of a wind power
plant. The wind turbine is responsible for generating energy and meets the task of using the
wind potential of a certain location to convert wind into electrical energy.
Vendors of wind turbines usually guarantee their customers a certain power curve and
technical availability in terms of energy production. To enable both the operators and owners
to verify the guaranteed performance of the wind turbines used, well-founded data providing
information on the wind conditions at the particular location shall be available.

61400-25-1 © IEC:2006(E) – 15 –
According to the standard IEC 61400-12-1, a separate wind power plant component, the
reference met mast, referred to in the further discourse as a meteorological system, should be
used for the measuring of the wind conditions, for example the wind speed, at a particular
location. The meteorological system supplies the data that may be required to correlate the
produced power output of individual wind turbines to the useable wind potential. On this basis,
it is possible to draw well-founded conclusions as to the real performance of a certain wind
turbine.
In addition to several wind turbines, integrated operation requires further components; the
energy produced in decentralised feeder and/or substations shall be collected and transported
to the final user via suitable power networks. This task is covered by the electrical system.
NOTE All electrical system issues concerning substations are targeted in the scope of the IEC 61850 series.
Another component, the wind power plant management system, ensures that the complete
system adapts itself to the static and dynamic conditions and requirements of the electrical
power connection (substation, utility network).
5.3 Generic requirements on communication
5.3.1 Communication capability
Wind power plants are monitored and controlled by various external actors, such as local or
remote SCADA systems, local real time build-in control systems, energy dispatch centres etc.
The objective of the monitoring of wind power plants is to provide the actors with information
on the complete system and the installed components. This information is deemed to be an
important knowledge basis for the control of wind power plants. For example, a SCADA
system which wants to stop the operation of a certain wind turbine in an integrated operation,
shall know how this component can be identified within the complete system and in which
status it is currently operating. The SCADA system shall, however, also know to which device
within the integrated operation it shall send which commands to make sure that the relevant
component is controlled as intended. To be able to check whether or not the command has
been executed, the SCADA system additionally requires a feedback from the wind power
plant.
Thus, wind power plants and external actors shall meet an essential prerequisite to be able to
exchange information within the framework of monitoring and control: They shall be able to
communicate with the outside world.
Typically, any wind power plant component, which needs to exchange information with other
components and actors, is therefore equipped with a so-called intelligent electronic device
(IED), which can send data to external receivers and receive data from external senders. A
wind turbine usually possesses a wind turbine controller, which is primarily responsible for the
internal monitoring and control of the wind power plant component, but also allows external
monitoring and control.
5.3.2 Communication content
Information is the content of the communication that takes place within the framework of
monitoring and control. The basic elements are raw data from the wind power plant
component, which shall be processed into specified information according to the IEC 61400-
25 series. There are five types of information that can be differentiated and are important for
the monitoring and control of wind power plants:
– process information,
– statistical information,
– historical information,
– control information,
– 16 – 61400-25-1 © IEC:2006(E)
– descriptive information.
Process, statistical and historical information provide the contents required for the monitoring
and control of wind power plants; this information shall be communicated by the wind power
plants. Process information provides information on the behaviour of certain complete
systems and their components, on their current states. Statistical information is often useful to
evaluate the operation of a wind power plant. By using historical Information, it might be
possible to track the operational trends in logs and reports.
Control information is intended to transmit the contents required for the control of wind power
plants, such as access profiles, set points, parameters and commands; this information shall
first be communicated to wind power plants by certain actors. Wind power plants shall store
control information and provide this for further communication to sub-processes.
Descriptive information is the type and the accuracy of the information, as well as the time
and the data description.
5.3.3 Communication functions
The actors communication for monitoring and controlling the wind power plants require special
functions to configure, perform and monitor the information exchange with wind power plants.
These functions can be divided into the following two main categories:
– operational functions,
– management functions.
Operational functions (manual or automatic) are used by the actors to obtain information on
wind power plants and to send control instructions to wind power plants. The operational
functions include:
– monitoring,
– control,
– data retrieval,
– logging,
– reporting.
Table 1 provides an overview of the ranges of application of the operational functions.
Table 1 – Operational functions
Operational functions Range of application (practical use)
Monitoring Operational function used for local or remote observation of a system or a
process for any changes which may occur over time. The term can also be
used for observation of the behaviour of a data value or a group of data values.
Control Changing and modifying, intervening, switching, controlling, parameterisation,
optimising of wind power plants.
Data retrieval Collecting of wind power plant data.
Logging Logging is a function intended for sequential recording of data and events in
chronological order. The result of the logging is a log.
Reporting The reporting is a function intended to transfer data from a server to a client,
initiated by a server application process.

Management functions are required for the higher-lever management of the information
exchange. They are used by actors to secure integrity of the monitoring and control process.
The management functions included are as follows:

61400-25-1 © IEC:2006(E) – 17 –
– user/access management,
– time synchronization,
– diagnostics (self-monitoring),
– system setup.
Table 2 provides an overview of the ranges of application of the management functions.
Table 2 – Management functions
Management functions Range of application (practical use)
User/access management Setting up, modifying, deleting users (administratively), assigning access
rights (administratively), monitoring access
Time synchronisation Synchronisation of devices within a communication system.
Diagnostics (self-monitoring) This function is used to set up and provide for self-monitoring of the
communication system.
System setup functions Defining how the information exchange will take place; setting, changing
and receiving (retrieval) of system setup data.

5.4 Communication model of the IEC 61400-25 series
5.4.1 General
The IEC 61400-25 series defines a communication model for the monitoring and control of
wind power plants, taking into account all requirements made with reference to the
communication, on an abstract
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