draft document IEC 61400-25-6 - scc-online.de

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Updated proposal for IEC61400-25-6 to be discussed in further details at the
working group meeting in Madrid 25.- 26.09.2007 – Carsten Andersson & Knud
Johansen.
WIND TURBINES
Part 25-6:
Communications for monitoring and control of wind power plants –
Logical node classes and data classes for condition monitoring
Version: 61400-25-6_R0-4-WD_2007-09-11, rev. 2
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CONTENTS
FOREWORD.........................................................................................................................4
INTRODUCTION...................................................................................................................5
1 Scope ............................................................................................................................9
1.1 Setup and control of condition monitoring systems ........................................................10
1.2 Condition monitoring techniques ...................................................................................10
2 Terms and definitions ...................................................................................................12
3 Abbreviated terms ........................................................................................................14
4 General ........................................................................................................................17
4.1 Condition Monitoring as related to the logical node classes ...........................................17
4.2 Logical Node Classes related to condition monitoring ....................................................17
4.3 Condition monitoring data .............................................................................................17
4.4 Condition Monitoring Data Types ..................................................................................18
4.5 Condition Monitoring and active power bins...................................................................19
4.6 Modelling the information from the wind turbine.............................................................19
4.7 Mandatory Measurements.............................................................................................21
5 Wind Turbine Condition Monitoring Information .............................................................22
5.1 General Structure of WCON Class information ..............................................................22
5.2 Example of a WCON Class ...........................................................................................22
5.3 Examples of WCON Class logical node addresses from the table: .................................25
5.4 Examples of WCON Classes not covered by the example..............................................25
6 Common Data Classes .................................................................................................25
6.1 Basic Concepts for Common Data Classes....................................................................25
6.2 Structure of Common Data Classes...............................................................................27
6.3 Common Data Class Attribute types..............................................................................27
6.3.1 Common Data Class attributes types inherited from IEC 61400-25-2 .........27
6.4 Common data Class attributes types inherited from IEC 61850-7-3 ................................27
6.5 Vector ..........................................................................................................................27
6.6 Point ............................................................................................................................27
6.7 RangeConfig ................................................................................................................27
6.8 ScaledValueConfig .......................................................................................................28
6.9 Wind turbine condition monitoring specific common data classes (CDC) ........................28
6.9.1 Scalar Value (SV) ....................................................................................28
6.9.2 Vector Value (VV) ....................................................................................28
6.9.3 Scalar Value Array (SVA) .........................................................................29
6.9.4 Setpoint Array (SPA)................................................................................29
6.9.5 Data File (DAF)........................................................................................29
Annex A (Informative) Application of Shaft and Bearing position numbering for
annotating frequency spectra.......................................................................................30
A.1 General ........................................................................................................................30
A.2 Example with gearbox...................................................................................................30
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Annex B (Informative) Examples of trend histories of mandatory measurements to be
used for due diligence etc.............................................................................................31
B.1 Trend history of Generator measurements.....................................................................31
Figure 1 – The two major information and information exchange models ................................6
Figure 2 – Conceptual information and information exchange model of IEC 61400-25-6 .........7
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
WIND TURBINES –
Part 25-6:
Communications for monitoring and control of wind power plants –
Logical node classes and data classes for condition monitoring
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organisation for standardisation comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardisation in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organisations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International
Organisation for Standardisation (ISO) in accordance with conditions determined by agreement between the
two organisations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
Recipients of this document are invited to submit, with their comments, notification of
any relevant patent rights of which they are aware and to provide supporting documentation.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IEC 61400-25 consists of the following parts, under the general title Communications for
monitoring and control of wind power plants:
Part 25-1: Overall description on principles and models
Part 25-2: Information models
Part 25-3: Information Exchange Models
Part 25-4: Mapping to communication profile
Part 25-5: Conformance testing
Part 25-6: Logical node classes and data classes for condition monitoring 1
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INTRODUCTION
IEC 61400-25 defines information models and information exchange models for monitoring
and control of wind power plants. The modelling approach (for information models and information
exchange models) of IEC 61400-25-2 and IEC 61400-25-4 uses abstract definitions of
classes and services such that the specifications are independent of specific communication
protocol stacks, implementations, and operating systems. The mapping of these abstract definitions
to specific communication profiles is defined in IEC 61400-25-4.
The definitions in parts IEC 61400-25-1 to IEC 61400-25-5 apply also for this part 6 of the
standard series
The purpose of this draft of Part 6 is to define an information model for condition monitoring
information and to define the necessary extensions to the already existing parts of IEC 61400-
25 in order to handle information related to condition monitoring of wind turbines.
Condition monitoring definition
In the context of this standard condition monitoring is taken to mean a process with the purpose
of watching machinery for a period of time in order to evaluate the state of the machinery
and any changes to it, in order to detect early signs of impending failure.
Condition monitoring is most frequently used as a Predictive or Condition-Based Maintenance
technique (CBM). However, there are other predictive maintenance techniques that can also
be used, including the use of the Human Senses (look, listen, feel, smell etc.) or Machine Performance
Monitoring techniques. These would not be considered to be condition monitoring
for the purposes of this standard.
Condition monitoring techniques
These include, but are not limited to techniques such as:
• Vibration measurements and analysis
• Oil analysis
• Temperature measurement
• Strain gauge measurement
• Etc.
Equipment can be monitored by using advanced instrumentation as well as using a manual
process.
Condition monitoring devices
The information consumed and generated by condition monitoring functions may be located in
different physical devices. Some information may be located in the turbine controller device
(TCD) while other information may be located in an additional condition monitoring device
(CMD). Various actors may request to exchange data located in the TCD or CMD. A SCADA
device may want to receive data from the TCD or CMD; a CMD may want to receive data from
TCD and vice versa. The information exchange between any two devices requires the use of
information exchange services defined in IEC 61400-25-3 or added in this part 6. A summary
of the above is depicted in Figure 1.
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Actors like
SCADA, Operator, Network
Control Center, …
25-xx
Information
Exchange
…
Logical Nodes and Data
25-3/4
Information
Scope of
standard
25-3/4 & 6
Information
Exchange
Exchange
Turbine control device or function
with Logical Nodes and Data (25-2)
Actors like SCADA, Operator, Network
Control Center, Owner, Maintenance, …
25-3/4 & 6
Information
Exchange
Condition monitoring device or function
with Logical Nodes and Data (25-2/6)
Gearbox
Generator
Brake
Tower
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TC/CM
Figure 1 – The two major information and information exchange models
The use case of having the CM functions located in the TCD is a special use case. That use
case does not require information exchange services for the information exchange between
the CM functions and TC functions. The case of having separate devices is the more comprehensive
use case. This is used as the basic topology in this part of the standard. The special
case of both functions in one device could be derived from the most general use case.
It may also be required to build a hierarchical model of TC and CM devices/functions. The last
but one box in the figure indicates that case. A simple CMD (providing measured values and
status information and very basic monitoring capabilities) may be located close to the turbine.
A second CMD may be located in the wind park control room. This CMD may retrieve information
from the underlying CMD or TCD and may further process and analyse the measured values
and status information.
Note 1: The location of devices and functions (more centralized or decentralized topology) is outside the scope of
this standard.
Figure 2 below depicts the basic concept of the information and information exchange models.
…
…

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Outside
scope
Actor
e. g.
Analysis,
SCADA,
Maintenance
part of central
Condition Monitoring
Client
Information exchange
Information exchange
model (get, set, report,
model (get, set, report,
log, control, publish /
log, control, publish /
subscribe, …)
subscribe, …)
IEC 61400-25-3
IEC 61400-25-3
Wind power plant
Wind power plant
information model
information model
IEC 61400-25-2/-6
IEC 61400-25-2/-6
Server
Information exchange
Information exchange
model (get, set, report,
model (get, set, report,
log, control, publish /
log, control, publish /
subscribe, …)
subscribe, …)
IEC 61400-25-3
IEC 61400-25-3
Wind power plant
Wind power plant
information model
information model
(aging, …)
(aging, …)
IEC 61400-25-6
IEC 61400-25-6
Communication model of IEC 61400-25
Messaging through
Messaging through
mapping to
mapping to
communication
communication
profile (Records,
profile (Records,
Read, write, ...
Read, write, ...
message)
message)
IEC 61400-25-4
IEC 61400-25-4
part of turbine Controller
Server
Wind power plant
Wind power plant
information model
information model
(rotor speed, break
(rotor speed, break
status, total power
status, total power
production, …)
production, …)
IEC 61400-25-2
IEC 61400-25-2
Information exchange
Information exchange
model (get, set, report,
model (get, set, report,
log, control, publish /
log, control, publish /
subscribe, …)
subscribe, …)
IEC 61400-25-3
IEC 61400-25-3
part of local Condition
Monitoring
Server
Information exchange
Information exchange
model (get, set, report,
model (get, set, report,
log, control, publish /
log, control, publish /
subscribe, …)
subscribe, …)
IEC 61400-25-3
IEC 61400-25-3
Wind power plant
Wind power plant
information model
information model
(Vibration samples,
(Vibration samples,
aging, …)
aging, …)
IEC 61400-25-6
IEC 61400-25-6
Version 61400-25-6_R0-4-WD_2007-09-11
Outside
scope
Wind power
plant
component
e. g. wind turbine
Application
Figure 2 – Conceptual information and information exchange model of IEC 61400-25-6
Condition Monitoring Value Chain
In automatic condition monitoring, when any monitored and predefined condition limit is exceeded,
a signal or output is turned on. This signal can be used by a Condition Monitoring
Supervision function to generate actionable information which can be used by a service organisation
to create work orders. Figure 3 below illustrates the value chain of a system using
condition monitoring to perform condition based maintenance.
The figure illustrates how data are refined and concentrated through the value chain, ending
up wit the ultimate goal of condition based maintenance the work order to the service staff.

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Figure 3 – The value chain of condition based maintenance
Figure 3 illustrates the scope of IEC 61400-25-6 which is the two first levels of the value
chain. That is, the Local condition monitoring and data acquisition performed by the condition
monitoring device located in the wind turbine and the central condition monitoring performed
by the Central Condition Monitoring Server. The decreasing sizes of the boxes in the value
chain illustrate the data reduction and the data refinement process.
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WIND TURBINES –
Part 25-6:
Communications for monitoring and control of wind power plants –
Logical node classes and data classes for condition monitoring
1 Scope
This standard defines the information models related to condition monitoring for wind power
plants and the information exchange of data values related to these models.
Condition monitoring relies mainly on the following kinds of information:
1. Time waveform records (samples) of a specific time interval to be exchanged in real-time
or by files for analysis (e.g. acceleration, position detection, speed, stress detection)
2. Status information and measurements (synchronized with the waveform records) representing
the Turbine Operation Conditions.
3. Results of Time waveform record analysis of vibration data (scalar values, array values,
statistical values, historical (statistical) values, counters and status information).
4. Results of oil debris analysis.
It is the purpose of this standard to model condition monitoring information by using the modelling
approach as described in clause 6.2.2 of 61400-25-1 and by extending the already existing
information model as indicated in Clause 6 of 61400-25-2.
Fig 4 – Structure of wind power plant information model
By the use of already defined logical nodes and the table of abbreviated terms as defined in
IEC 61400-25-2, and by describing a logical node WCON for data related to condition monitoring
data classes, data for condition monitoring classes shall be mapped by extending the
table of abbreviated terms from 61400-25-2 with abbreviations related to condition monitoring.
Refer to section 3 of this document.
Note 1: Proposals for additional abbreviations are marked with yellow in the table.
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This standard describes the data model for the following categories of data to be retrieved
from the wind turbine condition monitoring system:
1. Scalar data
2. Arrays of Scalar data
3. Vector data
4. Data files
5. Trigger Options
Note 2: Trigger options refer to IEC 61400-25-2 Table 25. This is a notification that a state or value change has occurred.
1.1 Setup and control of condition monitoring systems
It is not within the scope of the standard to setup and control the condition monitoring system
1.2 Condition monitoring techniques
It is not within the scope of this standard to define how to implement the condition monitoring
of wind turbines and to specify allowable limits for measured data. This work is done by other
standardisation committees such as “Richtlinie VDI 3834 Messung und Beurteilung der
mechanischen Schwingungen von Windenergieanlagen und deren Komponenten.
Impacts on other parts of IEC 61400-25
This proposal for 61400-25-6 will have some implications on the following parts of 61400-25
1. Extension of the Logical Node Classes as defined in IEC 61400-25-2 to comprise the information
related to condition monitoring systems. WTUR for status information of the
condition monitoring device and WALM for inclusion of alarms generated by the condition
monitoring system into the general alarm overview.
2. Extensions of the Information Exchange Model as defined in IEC 61400-25-3 to handle the
Data file entity and the Vector entity.
3. Extension of the Mapping to communication profile as defined in IEC 61400-25-4 to handle
the Data File entity and the Vector entity.
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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 61400-25-1:2006, Communications for monitoring and control of wind power plants –
Overall description on principles and models
IEC 61400-25-2:2006, Communications for monitoring and control of wind power plants -- Information
Exchange Model
IEC 61400-25-3:2006, Communications for monitoring and control of wind power plants -- Information
Models
IEC 61400-25-4, Communications for monitoring and control of wind power plants -- Mapping
to communication profile1
IEC 61850-7-4 Amendment 1, Communication networks and systems in substations – Part 7-
4: Basic communication structure for substations and feeder equipment – Compatible logical
node classes and data classes
IEC 60255-24:2001, Electrical relays – Part 24: Common format for transient data exchange
(COMTRADE) for power systems
ISO 10816/1-6 “Mechanical vibration – Evaluation of machine vibration by measurements on
non-rotating parts”
—————————
1 To be published
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2 Terms and definitions
For the purpose of this document, the terms and definitions defined in part IEC 61400-25-1
and the following apply.
Editor’s note: The following list is not complete. This section shall be updated in case more terms and definitions
will be required for part 25-6.
2.1
actor
Any entity that receives (sends) data values from (to) another device. Examples of actors
could be SCADA systems, maintenance systems, owner, etc.
2.2
mandatory
Defined content must be provided in compliance to this standard.
2.3
Optional
Defined content can be optionally provided in compliance to this standard.
2.4
Conditional
Defined content can be provided in compliance to this standard if certain conditions are present.
2.5
Scalar value
A Scalar value is a quantity which can be described by a single number, such as a temperature.
Scalar values are very suitable for historical trending and statistical purposes.
2.6
Data file
In a computer system, a data file is an entity of data available to system users (including the
system itself and its application programs) that is capable of being manipulated as an entity
(for example, moved from one file directory to another). The file must have a unique name
within its own directory. Some operating systems and applications describe files with given
formats by giving them a particular file name suffix. (The file name suffix is also known as a
file name extension.)
2.7
Peak Value
The Peak Value is the maximum excursion of a time wave form from its mean value within a
specific time interval.
2.8
Peak-to-Peak Value
The difference between the positive and negative extreme values of a time wave form.
2.9
Crest Factor
The crest factor of a waveform is the ratio of the peak value of a time waveform to the RMS
value of the time wave form within a specific time interval. It is also sometimes called the
"peak-to-RMS-ratio".
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2.10
RMS Value
RMS stands for Root Mean Square, and is a measure of the level of a signal. It is calculated
by squaring the instantaneous value of the signal, averaging the squared values over time,
and taking the square root of the average value. The RMS value is the value which is used to
calculate the energy or power in a signal.
2.11
Band pass (BP)
A filter that only passes energy between two frequencies which are called the lower and upper
cut-off frequencies. Band pass filters can be fixed, where the cut-off frequencies are constant,
and can be variable, where the cut-off frequencies are varied with time.
2.12
Order
An order is a multiple of some reference frequency. An FFT spectrum plot displayed in orders
will have multiples of running speed along the horizontal axis. Orders are commonly referred
to as 1x for running speed, 2x for twice the running speed, and so on. When an Order is an integral
number of the running speed it may be referred to as a harmonic of the running speed.
E.g. 2x may be referred to as the 2nd harmonic of the running speed.
2.13
Order Analysis
Ability to study the amplitude changes of specific signals that are related to the rotation of the
device under observation.
2.14
UFF 58
De-facto standard file format for storing noise and vibration information in the area of the car
industry. The format can be read by analyzers from several vendors on the market
2.15
ISO 10816 1-6
A widely used standard for evaluation of vibration measurements. It consists of 6 parts.
ISO10816-1 is the basic document describing the general requirements for evaluating machinery
vibration using casing and/or foundation measurements. Subsequent parts of each series
of documents apply to different classes and types of machinery, and include specific
evaluation criteria used to assess vibration severity. The Vibration Magnitude is defined within
this group of standards as the maximum value of the broadband RMS value (acceleration, velocity
or displacement) in the specified frequency range (typically from 10 to 1,000 Hz).
2.16
HFBP – High Frequency Band Pass
Overall measurement covering a high frequency range of 1 kHz – 10 kHz. Impacts from bearing
faults often results in one or more resonance effects in the high frequency range. Measurements
limited to this frequency range are therefore well suited for detecting bearing faults.
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3 Abbreviated terms
CDC Common Data Class
CM Condition Monitoring (Function)
CMD Condition Monitoring Device
DC Data Class
ING Common Data Class for Integer Setting value (see IEC 61850-7-3)
LCB Log Control Block
LD Logical Device
LN logical node
LPHD Logical node Physical Device Information
RCB Report Control Block
RMS Root Mean Square
SAV Common Data Class for Sampled Analogue Values (see IEC 61850-7-3)
SHS Statistical and Historical Statistical data (as defined in IEC 61400-25-2 Annex A)
SMV Sampled Measured Values; some times short: SV = Sampled Values
TC Turbine Controller (Function)
TCD Turbine Controller Device
TOC Turbine Operation Conditions
WPP Wind Power Plant
WT Wind Turbine
Abbreviated terms used to build names of data classes found in LNs shall be as listed below.
Editor’s note The following list has been copied from Draft IEC 61400-25-2 (CDV). The list needs to be updated
in case we need new terms/abbreviations for part 25-6.
EXAMPLE RotPos is constructed by using two names “Rot” which stands for Rotor and “Pos” which stands for
“Position”. Thus the concatenated name represents a “Rotor Position”.
Note 3: The items of the table marked in yellow are examples of abbreviations to be used for creating data classes
for the WCON logical node.
Term Description
A Current
AC AC
Ack Acknowledge
Acs Access
Act Actual
Alm Alarm
An Analogue
Ane Anemometer
Ang Angle
Alt Altitude
At Active (real)
Atv Activate
Av Average
Avl Availability
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Term Description
Az Azimuth
Bec Beacon
Bl Blade
Blk Blocked
Brg Bearing
Brk Brake
Cab Cable
Ccw Counter clockwise
Ch Characteristic
Chg Change
Chk Check
Chrg Charge
Cl Cooling
Cm Command

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Term Description
Cnv Converter
Ct Counting
Ctl Control
Cw Clockwise
d Description
Dat Data
Db Deadband
DC DC (Direct Current)
Dcl Dc-link
Dec Decrease
Dehum De-humidifier
Del Delta
Det Detection
Dir Direction
Disp Displacement
Dly Daily
Dmd Demand
Drv Drive
Dn Down
Egy Energy
Elev Elevator
Emg Emergency
En Enable
Ent Entrance
Ety Empty
Evt Event
Ex External
Ext Excitation
Flsh Flash
Flt Fault
Ftr Filter
Gbx Gearbox
Gra Gradient
Gri Grid
Gn Generator
Gs Grease
Hi High
Hly Hourly
Hor Horizontal
Ht Heating
Htex Heat-exchanger
Hum Humidity
Hy Hydraulic
Hz Frequency
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Term Description
Ice Ice
Id Identifier
Idl Idling
Inc Increase
Inj Injection
Inl Inline
Inlet Inlet
Inst Instantaneous
Intl Internal
Lev Level
Log Log
Lift Lift
Lim Limit
Lo Low
Lu Lubrication
Lum Luminosity
Man Manual
Max Maximum
Met Meteorological
Min Minimum
Mly Monthly
Mod Mode
Mx Measurement
Mul Multiplier
Nac Nacelle
Num Number (size)
Of Off line
Oil Oil
Op Operate, Operating
Oper Operator
Ov Over
Per Period, Periodic
PF Power factor
Ph Phase
Pmp Pump
Pl Plant
Plu Pollution
Pos Position
Pres Pressure
Prod Production
Pt Pitch
Ptr Pointer
Pwr Power
q Quality

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Term Description
Rdy Ready
Rep Report
Rms Root-mean-square
Rng Range
Roof Roof
Rot Rotor (windturbine)
Rs Reset
React Reactive
Rtr Rotor (generator)
Sdv Standard deviation
Sev Severity
Seq Sequence
Shf Shaft
Smk Smoke
Smp Sampled
Sp Setpoint
Spd Speed
St Status
Sta Stator
Stdby Standby
Stop Stop
Str Start
Sw Switch
Sys System
T Timestamp
Tm Timer
Tmp Temperature
Tot Total
Tow Tower
Tra Transient
Trf Transformer
Trg Trigger
Torq Torque
Tur Turbine
Un Under
Urg Urgent
V Voltage
VA Apparent power
Val Value
Vals Values
Ver Vertical
Vib Vibration
Vis Visibility
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Term Description
Wly Weekly
Wup Windup
Xdir X-direction
Ydir Y-direction
Yly Yearly
Yw Yaw
Lt Lateral
Pc Power Class
Up Up (opposite to Down)
St State
Acc Accelerometer
1Ps 1’st Planetary Stage
2Ps 2’nd Planetary Stage
Iss Intermediate Speed Stage
Hss High Speed Stage
Stg Stage (1, 2, 3 .. etc.)
Fr Front
Rr Rear
Ax Axial
Ra Radial
Up Up
Deb Debris
Sld Structural Load

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4 General
4.1 Condition Monitoring as related to the logical node classes
Values for condition monitoring can all be related to a particular part of the turbine, exactly as
a SCADA value such as temperature can be related to a part of the turbine. Therefore the
data model as described in 61400-25-2 for the SCADA values can be applied to condition
monitoring data.
4.2 Logical Node Classes related to condition monitoring
Table 1: Wind Turbine Condition Monitoring related node classes:
WTUR Wind turbine general information
WALM Wind power plant alarm information
WCON Wind condition monitoring information
The WTUR node class is related to wind turbine condition monitoring as the condition monitoring
system may refer to information from this class.
The WALM node class is related to wind turbine condition monitoring as alarms from the condition
monitoring system may be referred to by this class.
4.3 Condition monitoring data
As shown in the table below, each of the data categories as specified by the Common Data
Classes defined in the scope of this standard can be used by a number of different data types
used in a condition monitoring system.
In particular, when using vibration monitoring it is possible to derive several measurement
values of different data types from the transducer signal by using filtering and other post
processing techniques. The table below shows some examples of relationships between data
categories as specified by the Common Data Classes and the data types of the measurements.
Table 2: Wind Turbine Condition Monitoring Specific information categories
Data type examples Category
ISO RMS according to ISO 10816 Scalar Value
Crest Factor Scalar Value
Band pass Value (E.g. picking up the tooth meshing frequency) Scalar Value
Power Spectrum (Auto spectrum) result of an FFT analysis Array of Scalar Values
Envelope Spectrum (result of an FFT analysis of a pre-processed time waveform) Array of Scalar Values
Time Wave Form Array of Scalar Values
Filtered Time Wave Form Array of Scalar Values
Picture Data File
Thermo graphic Data Data File
Time Wave form on ASCII format Data File
Hi, HiHi, Lo, LoLo Trigger Option
Danger, Alert Trigger Option
Alarm, Warning Trigger Option
The data types used for condition monitoring are many and may be developed for specific application
and their number may increase as new development goes on. The data categories
are more general, there are not so many and the number of different data categories is more
static.
The figure below illustrates the relationship between Category, Data Type and Measured Values.
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Figure 5 – Relationship between Data category, Data Type and measured values
4.4 Condition Monitoring Data Types
The data types to be used for monitoring wind turbines shall be divided between a group of
data types defined as mandatory by this standard and a group which are optional and vendor
specific.
The objective of the mandatory data types is to create a uniform background for evaluating
the state of a turbine. Note! This standard does not specify any recommended levels of these
data. This is subject for other standards or for internal recommendations developed by individual
turbine operators.
The objective of the vendor specific data types are to adapt to the fact that different vendors
have developed different philosophies for monitoring wind turbines and for allowing the future
use of monitoring techniques which may not have been invented yet
The data types specified for the condition monitoring system for a particular part of the turbine
shall be assigned a unique number as shown in the table below. This data type is then used
in the data model as reference when referring to measurements of a certain data type. For the
same location on the machine there may exist several measurements of different data types.
Table 3: Numbers used to describe measurement types: D11-D99 is Vibration Related Values – Vendor Specific
Data Type Number Abbreviation. Explanation
Reserved Data Types
Vendor specific data types
D01 RMS Overall RMS according to ISO 10816
D02 HFBP High Frequency Band pass. Range 1kHz – 10kHz.
D03 TMF Tooth Meshing Frequency
D04 2TMF 2 Order Tooth Meshing Frequency
D05 3TMF 3 Order Tooth Meshing Frequency
D06 1MA 1 st Order Magnitude
D07 2MA 2 nd Order Magnitude
D08 3MA 3 rd Order Magnitude
D09 TwRMS Used for Tower Measurements. Range 0.1Hz – 100Hz.
D10 - Not Used
D11 BP 4kHz-6kHz
D12 BP 100Hz – 500Hz
D13 .
D14 .
D15 .
D16 BPFO Ball Passing Frequency Outer Ring
D17 BPFI Ball Passing Frequency Inner Ring
D18 FFT 0-10kHz
D19 TWF Time Wave Form
.
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4.5 Condition Monitoring and active power bins
A wind turbine in principle operates over a wide range of wind speeds causing a large range
of loads on the tower, blades and related mechanical structures. An adaptive monitoring technique
is often applied to secure a higher degree of reliability and repeatability of measurements
used to detect developing faults in the full operating range, thus reducing the risk of
false alarms. In order to adapt to the varying operating conditions, data can be stored in several
“active power bins”. The basic principle of condition monitoring is to compare new measurements
with old. The effect of changing operating conditions can be limited by only comparing
data belonging to the same “active power bin.
Active power are used for the adaptive monitoring technique rather than the wind speed as
the vibration level measured on the turbine components are closely related to the active
power production of the turbine. Using the active power also ensures that vibration measurements
only are recorded when the turbine is producing.
Fig. 6 – Active power bin concept. Example of vibration data which is individually compared
to alarm limits for five different “active power bins” with individual alarm trigger
levels.
4.6 Modelling the information from the wind turbine
When referring condition monitoring information to a wind turbine it is necessary in many
cases to be able to relate a measurement to a specific location on the turbine.
E.g. A tooth meshing frequency (TMF) must be related to a specific shaft of the gearbox and
the vibration level of the outer ring frequency of a bearing (BPFO) must be related to a specific
shaft and a bearing position on that shaft.
The schematic illustration below shows the principle of the shaft and bearing numbering used
to relate a particular measurement to a location on the turbine. The numbering of the shafts
and bearings are done with increasing numbering downwind direction, following the transmission
of the force from the wind turbine blades. Note! The numbering also applies to other machine
structures than the one shown in this section.
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Fig. 7 - A schematic view of a wind turbine showing the shaft and bearing numbering
principle.
Shaft Number Bearing Position
1 Main Shaft 1.1 Main bearing
2 Carrier 2.1 Carrier Bearing
3, 4, 5 Planet Shaft 1, 2 and 3 3.1, 4.1, 5.1 Plant Bearings
6 Sun Shaft 6.1, 6.2 Sun Shaft Bearings
7 Intermediate Shaft 7.1, 7.2 Intermediate Shaft Bearings
8 High Speed Shaft 8.1, 8.2 High Speed Shaft bearings
9 Generator Shaft 9.1, 9.2 Generator Shaft Bearings
Note: An example from a wind turbine without a gearbox might be placed here for illustration
of the large variety of mechanical designs on the market.
The following convention shall be used when referring to wind turbine vibration measurements:
1) Overall vibration levels or Band pass measurements covering a wide frequency range
measured by transducers located on the different parts of the turbine cannot be related to
specific shafts or bearings. Such measurements shall be identified by the location of the
sensor using the abbreviated terms defined in section 3, and the name or number of the
particular measurement. Refer to Example 1 below.
2) Vibration levels which can be referred to a specific shaft, such as a tooth meshing frequency
or order measurements shall be referred to by the shaft number. As an option the
shaft number can be preceded by the abbreviation as specified in section 3, if desired. Refer
to Example 2 below.
3) Vibration levels which can be referred to a specific bearing, such as the Ball Passing Frequency
of the Outer ring shall be referred to by the shaft number and bearing position. Refer
to Example 3 below.
Examples:
1) The Overall RMS level measured by the transducer on the Intermediate Stage of the
gearbox shall be referred to as: Iss.RMS.
As the RMS is a standardized measurement type it can be referred to by its name.
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2) The vibration level of the Tooth Meshing Frequency of the Intermediate Shaft shall be referred
to as: 7.TMF or Iss.7.TMF
As the TMF is a standardized measurement type it can be referred by its name.
3) The vibration level of the Ball Passing Frequency Outer Ring of the downwind bearing of
the Intermediate Shaft shall be referred to as: 7.2.D16. or Iss.7.2.D16.
The number “16” refers to table 3 of the previous section. As the BPFO is a vendor specified
measurement it is referred to by its number.
4.7 Mandatory Measurements
The objective of the mandatory measurements is to provide a way of evaluating the overall
state of a wind turbine without going into diagnostic details. The selected data types are well
suited for long term trending to study the development in the vibration levels. It is beyond the
scope of this standard to specify for example max. allowable limit values for these measurements.
Defining specific levels for vibrations can be applicable for turbine operators and vendors e.g.
in the following situations:
• When a warranty period start
• When a warranty period expires
• When main components of the WTG is retrofitted or exchanged.
• When a turbine operator is making a due diligence before acquiring a wind power plant
• When benchmarking wind power plants and wind turbines
The table below lists the proposed mandatory measurements for each turbine stage:
Planetary Stages
Data Type Number Abbreviation Explanation
D01 RMS Overall RMS after the ISO-10816 standard (10Hz -1000Hz)
D02 HFBP High Frequency Bandpass (1kHz – 10kHz)
D03 TMF Tooth Meshing Frequency
D04 2TMF 2 Order Tooth Meshing Frequency
D05 3TMF 3 Order Tooth Meshing Frequency
Other Gearbox Stages
Data Type Number Abbreviation Explanation
D01 RMS Overall RMS after the ISO standard
D02 HFBP High Frequency Bandpass (1kHz – 10kHz)
D03 TMF Tooth Meshing Frequency
D04 2TMF 2 Order Tooth Meshing Frequency
D05 3TMF 3 Order Tooth Meshing Frequency
D06 1MA 1 st Magnitude
D07 2MA 2 nd Magnitude
Generator Drive End and Non Drive End
Data Type Number Abbreviation Explanation
D01 RMS Overall RMS after the ISO-10816 standard (10Hz -1000Hz)
D02 HFBP High Frequency Band pass (1kHz – 10kHz)
D06 1MA 1 st Magnitude
D07 2MA 2 nd Magnitude
Tower Down Wind and Tower Lateral
Data Type Number Abbreviation Explanation
D01 RMS Overall RMS after the ISO-10816 standard (10Hz -1000Hz)
D06 1MA 1 st Order Magnitude
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D08 3MA 3 rd Order Magnitude
5 Wind Turbine Condition Monitoring Information
As shown in the table below the data class name for the condition monitoring parameters
based upon vibration starts with the abbreviation “Vib”.
5.1 General Structure of WCON Class information
The general structure of the WCON class information is specified in the table below.
WCON class
Attribute Name Attr. Type Explanation M/O/C
Specified by combining the optional and mandatory
fields.
Data
Type of Information M
Part of the turbine – Related Vibration Sensor O
Data related to a turbine stage M/O
Data related to a shaft M/O
Data related to a shaft and bearing position O
Explanation of WCON class content
• This denotes the data class as specified by the abbreviations in section 3.
E.g. Vib – Vibration.
• This denotes the part of the turbine as specified by the abbreviations in section
3. E.g. Hss – High Speed Stage
• This denotes the vibration data type as specified in section 4.4. E.g. ISO
RMS.
• This denotes the shaft number as defined in section 4.6.
• This denotes the position of the bearing on the shaft as defined in section 4.6.
• This defines the Bin where the measurement is stored as defined in section 4.5.
Bain may be active power bins for vibration measurements or bins for grouping particle
sizes in oil debris analysis. Bin number is left out for data types not related to a bin concept.
• The Common Data Class type of the measured data.
• M/O/C This denotes whether the information is Mandatory, Optional or Conditional.
5.2 Example of a WCON Class
The table below illustrates how a WCON Class may look for a simple wind turbine consisting
of a main bearing, a three stage gearbox and a generator stage. In this example data has
been grouped into 5 bins. Only fractions of the table are shown.
Note 1: The table shall not be taken as a recommendation. It purely shows the principle of how a WCON class
might be structured in practice.
WCON class
Attribute Name Attr. Type Explanation M/O
Specified by combining the optional and mandatory
fields.
Data
Vib Vibration M
1Ps First planetary stage accelerometer M/O
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RMS 1 SV Overall RMS of the 1 Pl. Stage M
RMS 2 SV Overall RMS of the 1 Pl. Stage M
RMS 3 SV Overall RMS of the 1 Pl. Stage M
RMS 4 SV Overall RMS of the 1 Pl. Stage M
RMS 5 SV Overall RMS of the 1 Pl. Stage M
HFBP 1 SV High Frequency Band pass of the 1 Pl. Stage M
HFBP 2 SV High Frequency Band pass of the 1 Pl. Stage M
HFBP 3 SV High Frequency Band pass of the 1 Pl. Stage M
HFBP 4 SV High Frequency Band pass of the 1 Pl. Stage M
HFBP 5 SV High Frequency Band pass of the 1 Pl. Stage M
3/ 4/ 5 TMF 1 SV Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 TMF 2 SV Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 TMF 3 SV Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 TMF 4 SV Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 TMF 5 SV Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 2TMF 1 SV 2. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 2TMF 2 SV 2. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 2TMF 3 SV 2. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 2TMF 4 SV 2. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 2TMF 5 SV 2. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 3TMF 1 SV 3. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 3TMF 2 SV 3. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 3TMF 3 SV 3. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 3TMF 4 SV 3. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 3TMF 5 SV 3. Tooth Meshing Frequency for Pl. Shafts M
3/ 4/ 5 1 D16 1 SV Vendor Specific – BPFO O
3/ 4/ 5 1 D16 2 SV Vendor Specific – BPFO O
3/ 4/ 5 1 D16 3 SV Vendor Specific – BPFO O
3/ 4/ 5 1 D16 4 SV Vendor Specific – BPFO O
3/ 4/ 5 1 D16 5 SV Vendor Specific – BPFO O
3/ 4/ 5 1 D17 1 SV Vendor Specific – BPFI O
3/ 4/ 5 1 D17 2 SV Vendor Specific – BPFI O
3/ 4/ 5 1 D17 3 SV Vendor Specific – BPFI O
3/ 4/ 5 1 D17 4 SV Vendor Specific – BPFI O
3/ 4/ 5 1 D17 5 SV Vendor Specific – BPFI O
D19 1 DAF Time Wave Form O
D19 2 DAF Time Wave Form O
D19 3 DAF Time Wave Form O
D19 4 DAF Time Wave Form O
D19 5 DAF Time Wave Form O
Iss Intermediate Speed Stage Accelerometer
RMS 1 SV Overall RMS of the Iss Stage M
RMS 2 SV Overall RMS of the Iss Stage M
RMS 3 SV Overall RMS of the Iss Stage M
RMS 4 SV Overall RMS of the Iss Stage M
RMS 5 SV Overall RMS of the Iss Stage M
7 TMF 1 SV Tooth Meshing Frequency for Iss Shaft M
7 TMF 2 SV Tooth Meshing Frequency for Iss Shaft M
7 TMF 3 SV Tooth Meshing Frequency for Iss Shaft M
7 TMF 4 SV Tooth Meshing Frequency for Iss Shaft M
7 TMF 5 SV Tooth Meshing Frequency for Iss Shaft M
7 2TMF 1 SV 2 nd Tooth Meshing Frequency for Iss Shaft
7 2TMF 2 SV 2 nd Tooth Meshing Frequency for Iss Shaft
7 2 D17 3 SV Vendor Specific – BPFI O
7 2 D17 4 SV Vendor Specific – BPFI O
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7 2 D17 5 SV Vendor Specific – BPFI O
D18 1 SVA Vendor Specific FFT 0-10kHz O
D18 2 SVA Vendor Specific FFT 0-10kHz O
D18 3 SVA Vendor Specific FFT 0-10kHz O
D18 4 SVA Vendor Specific FFT 0-10kHz O
D18 5 SVA Vendor Specific FFT 0-10kHz O
TowDnWd Tower Down Wind Accelerometer
TwRMS 1 SV Overall RMS M
TwRMS 2 SV Overall RMS M
TwRMS 3 SV Overall RMS M
TwRMS 4 SV Overall RMS M
TwRMS 5 SV Overall RMS M
1MA 1 SV Vibration at rotational speed M
1MA 2 SV Vibration at rotational speed M
1MA 3 SV Vibration at rotational speed M
1MA 4 SV Vibration at rotational speed M
1MA 5 SV Vibration at rotational speed M
3MA 1 SV Vibration at the blade passing frequency M
3MA 2 SV Vibration at the blade passing frequency M
3MA 3 SV Vibration at the blade passing frequency M
3MA 4 SV Vibration at the blade passing frequency M
3MA 5 SV Vibration at the blade passing frequency M
TowLt Tower Lateral Accelerometer M
TwRMS 1 SV Overall RMS M
TwRMS 2 SV Overall RMS M
TwRMS 3 SV Overall RMS M
TwRMS 4 SV Overall RMS M
TwRMS 5 SV Overall RMS M
1MA 1 SV Vibration at rotational speed M
1MA 2 SV Vibration at rotational speed M
1MA 3 SV Vibration at rotational speed M
1MA 4 SV Vibration at rotational speed M
1MA 5 SV Vibration at rotational speed M
3MA 1 SV Vibration at the blade passing frequency M
3MA 2 SV Vibration at the blade passing frequency M
3MA 3 SV Vibration at the blade passing frequency M
3MA 4 SV Vibration at the blade passing frequency M
3MA 5 SV Vibration at the blade passing frequency M
OilDeb Oil debris Analysis. Particle Count M
1Ps First planetary stage outlet O
Fe 1 SV Ferrous Particles 50-200µm O
Fe 2 SV Ferrous Particles 200-400µm O
Fe 3 SV Ferrous Particles > 400µm O
NonFe 1 SV Non Ferrous Particles 50-200µm O
NonFe 2 SV Non Ferrous Particles 200-400µm O
NonFe 3 SV Non Ferrous Particles > 400µm O
IssHss Intermed. stage & Highspeed Stage outlet O
Fe 1 SV Ferrous Particles 50-200µm O
Fe 2 SV Ferrous Particles 200-400µm O
Fe 3 SV Ferrous Particles > 400µm O
NonFe 1 SV Non Ferrous Particles 50-200µm O
NonFe 2 SV Non Ferrous Particles 200-400µm O
NonFe 3 SV Non Ferrous Particles > 400µm O
VibSp Vibration Setpoint Levels O
1PsHi First planetary stage accelerometer O
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RMS 1 SPV Setpoint Overall RMS of the 1 Pl. Stage O
RMS 2 SPV Setpoint Overall RMS of the 1 Pl. Stage O
RMS 3 SPV Setpoint Overall RMS of the 1 Pl. Stage O
RMS 4 SPV Setpoint Overall RMS of the 1 Pl. Stage O
RMS 5 SPV Setpoint Overall RMS of the 1 Pl. Stage O
HFBP 1 SPV Setpoint HFBP of the 1 Pl. Stage O
1PsHiHi First planetary stage accelerometer M
RMS 1 SPV Setpoint Overall RMS of the 1 Pl. Stage M
RMS 2 SPV Setpoint Overall RMS of the 1 Pl. Stage M
RMS 3 SPV Setpoint Overall RMS of the 1 Pl. Stage M
RMS 4 SPV Setpoint Overall RMS of the 1 Pl. Stage M
RMS 5 SPV Setpoint Overall RMS of the 1 Pl. Stage M
HFBP 1 SPV Setpoint HFBP of the 1 Pl. Stage M
5.3 Examples of WCON Class logical node addresses from the table:
Logical Node Address Meaning
WCON.Vib.1Ps.RMS.2 Overall RMS of 1st Planetary Stage Bin 2
WCON.Vib.Iss.7.TMF.4 Tooth Meshing Frequency of Intermediate Shaft Bin 4
WCON.Vib.Iss.7.2.D17.5 BPFI of the downwind bearing (Pos. 2) on the Intermediate Shaft Bin 5
WCON.OilDeb.IssHss.NonFe.2 Particle Count of non ferrous particles, 200-400µm, Intermediate & High
Speed Stage.
WCON.VibSp.IssHi.RMS.3 Hi Setpoint of the RMS measurement on the Intermediate Stage
5.4 Examples of WCON Classes not covered by the example
As not all cases are covered by the example in table examples of a few other logical node addresses
is listed in this section.
Logical Node Address Meaning
WCON.Vib.GnRa.RMS.2 Overall RMS of generator radial accelerometer. Bin 2
WCON.Vib.GnAxDnWd.RMS.3 Overall RMS of generator axial accelerometer mounted on the downwind
part of the generator. Bin 3.
WCON.Vib.Bl1.D20 Vendor specified measurement on Blade 1
Editor’s note It is the intention to cover any type of condition monitoring data by the model by applying other
types of abbreviations or add new to the table of terms in section 3. E.g Transformer Vibrations Vib.Trf….
6 Common Data Classes
6.1 Basic Concepts for Common Data Classes.
The Common Data Classes defines any data which is contained in the logical nodes. It is a
generic template used to define the specific data classes which contains the information.
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Fig. 8 – Wind Power Plant Information Model
Shared properties of a group of data classes of data defined in logical nodes are defined in a
common data class (CDC). A data class inherits all information (data and meta data) as specified
in its accompanying.
Examples of relationships between the Wind Power Plant Information Model and the examples
in this standard.
Information Model Example Explanation
LN WCON Logical Node for condition monitoring data
Attribute Name of data Class Vib.Iss.7.TMF Name for Intermediate Shaft TMF Vibration level.
CDC SV Scalar Value Common Data Class
Based on the requirements to information modelling for Wind Turbine Condition Monitoring, a
set of specific common data classes for wind power plants have been specified.
The modelling of the information related to condition monitoring for a wind turbine requires
some data classes to be specified in addition to the common data classes inherited from IEC
61400-25-2
The following common data classes shall be added in the definitions given in section 7 of IEC
61400-25-2.
a) Wind Turbine Condition Monitoring specific common data classes (CDC)
Scalar Value (SV)
Vector (VV)
Scalar Array (SVA)
Set Point Array (SPA)
Data File (DAF) (*note the class shall contain a file descriptor telling the format)
b) Common Data Classes inherited from IEC 61400-25-2
Set Point Value (SPV)
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Status Value (STV)
Alarm (ALM)
6.2 Structure of Common Data Classes
Refer to section 7.1.2 IEC 61400-25-2.
6.3 Common Data Class Attribute types
These are used to characterize the Attributes used to describe each of the Common Data
Classes.
6.3.1 Common Data Class attributes types inherited from IEC 61400-25-2
Only a subset of the Common data Class Attributes already defined in section 7.2 of IEC
61400-25-2 are used. A summary is given below:
7.2.1 Analogue Value and
7.2.1 Analogue Value (n) – denoting an array of analogue values
7.2.2 Time Stamp
7.2.3 Quality
7.2.4 Units
6.4 Common data Class attributes types inherited from IEC 61850-7-3
For ease of reference these attributes are repeated in this section.
6.5 Vector
Note4! Normally in condition monitoring we used the term phase instead of angle. To comply with common terminology
we may need another attribute.
Vector Type definition
Attr. Name Attr. Type Value/value Range M/O/C
Mag Analogue Value M
Ang Analogue Value M
6.6 Point
PointType definition
Attr. Name Attr. Type Value/value Range M/O/C
xVal Analogue Value M
yVal Analogue Value M
6.7 RangeConfig
RangeConfig Type definition
Attr. Name Attr. Type Value/value Range M/O/C
hhLim Analogue Value M
hLim Analogue Value M
lLim Analogue Value M
llLim Analogue Value M
Min Analogue Value O
Max Analogue Value O
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6.8 ScaledValueConfig
ScaledValueConfig Type definition
Attr. Name Attr. Type Value/value Range M/O/C
scaleFactor Analogue Value M
Offset Analogue Value M
6.9 Wind turbine condition monitoring specific common data classes (CDC)
Because the IEC 61400-25-6 uses a similar modelling approach as specified in IEC 61400-25-
2, some existing data classes shall be reused when modelling the condition monitoring information.
This section therefore only deals with the additional data classes for condition monitoring.
6.9.1 Scalar Value (SV)
Common Data Class Scalar Value (SV) comprises attributes which characterizes the size of a
physical quantity the size of which is specified completely by its magnitude. Examples of scalar
values from other areas is a quantity such as a mass or a temperature.
Note 5: The Measured Value (MV) Common Data Class might be applicable here. The reason for creating the SV
Class is to comply more to the terminology used within condition monitoring.
SV Class
Attribute Name Attribute Type FC TrgOp Explanation and value/range M/O
Data
6.9.2 Vector Value (VV)
Common Data Class Vector Value (VV) comprise attributes which characterizes the size of a
physical quantity that has both magnitude and direction. Magnitude, or "size" of a vector,
can be thought of as the scalar portion of the vector and is represented by the length of the
vector. By definition, a vector has both magnitude and direction. Commonly know vector
quantities are velocity and force. In the area of condition monitoring vector measurements are
mainly used for monitoring shaft behaviour.
VV Class
Attribute Name Attribute Type FC TrgOp Explanation and value/range M/O
Data
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6.9.3 Scalar Value Array (SVA)
The Scalar Value Array (SVA) is a collection of scalar values all having the same time stamp.
The Scalar value Array is used for FFT Spectra and Time Functions.
SVA Class
Attribute Name Attribute Type FC TrgOp Explanation and value/range M/O
Data
6.9.4 Set Point Array (SPA)
The set points array is used in connection with defining set point values such as Hi and HiHi
for Scalar Value Array Measurements.
SPA Class
Attribute Name Attribute Type FC TrgOp Explanation and value/range M/O
Data
6.9.5 Data File (DAF)
The Data File (DAF) is used for transferring data using a defined file format. Often time waveforms
are transferred in such a format to be compatible with various application software
packages used for analysis. File format often used are the UFF file format and the COM-
TRADE format.
DAF Class
Attribute Name Attribute Type FC TrgOp Explanation and value/range M/O
Data
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Annex A
(Informative)
Application of Shaft and Bearing position numbering for annotating
frequency spectra
A.1 General
When applying frequency spectra for analysis of vibration signal from wind turbines the different
peaks in the frequency spectrum are related to the different kinematical frequencies of for
example a gearbox. This annex shows how the shaft and bearing numbering system introduced
in section 4.6 of this standard, can be applied to annotate the peaks in the frequency
spectrum, thus illustrating the relationship to the different components of the wind turbine.
A.2 Example with gearbox
Fig. 9 - Frequency Spectrum from the intermediate speed sensor
In the frequency spectrum shown above the tooth meshing frequencies from three different
parts of a gearbox are annotated. The shaft numbers shown along with the annotation indicates
the origin of the frequency component.
3 – Planet shaft
7 – Intermediate Shaft
8 – High speed Shaft
Refer also to figure 7 in section 4.6.
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Annex B
(Informative)
Examples of trend histories of mandatory measurements to be used for
example for a due diligence and other purpose
B.1 Trend history of generator measurements
The example below shows how a report of mandatory measurements might look. Here is only
shown data for the generator in power bin 3. Each plot spans a period of 2 years with approximately
800-1000 measurements in each plot. The plots show that bearing fault has been
present on the generator drive end bearing in 2005. After repair the levels has dropped to a
constant low level.
It is seen from the plots that the HFBP which is sensitive to bearing failures provides a longer
lead time than the ISO RMS measurement. At a later stage when the bearing has deteriorated,
vibrations also start to rise in the frequency range covered by the ISO RMS value. The
1MA and 2MA rises at a very late stage when looseness and misalignment starts to affect the
rotor vibrations.
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Other annexes required as informative or normative to be agreed at
the working group meeting in Madrid – Carsten Andersson & Knud
Johansen.
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