The Net is the Automation.
|-> home > standardization > iec tc 88 >
IEC TC 88
Parts IEC 61400-25-1, -2, -3, and -5 just published!! See below links for previews.
TC 88 Projects related to IEC 61850:
Communications for monitoring and control of wind power plants:
1. Project PT 25:
The missing part IEC 61400-25-4 (Communication Mappings) is under way. All five optional mappings proposed for part IEC 61400-25-4 will be distributed with the New Work Proposal by end of 2006.
To meet the requirements of the wind power industry there are now five optional mappings (for IEC 61400-25-4) under preparation:
The only standardized mapping available for immediate use is the mapping published in the international standard IEC 61850-8-1 (MMS mapping). The implementations available for IEC 61850-8-1 can be used as they are!
2. Project PT 25-6:
Karlheinz Schwarz (SCC) is deeply involved in the standardization of IEC 61850 and IEC 61400-25 ...
This document addresses vendors (manufacturers, suppliers), operators, owners, planners, and designers of wind power plants as well as system integrators, utility companies operating in the wind energy market, and service and maintenance firms. IEC 61400-25 will be used world-wide as the international standard for communications in the domain of wind power plants.
IEC 61400-25 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 standard 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 document 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 this standard 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 this standard allows SCADA systems (supervisory control and data ac-quisition) 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 IEC 61400-25 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 per-spective unified definitions of common data minimize conversion and re-calculation of data values for evaluation and comparison of all their wind power plants.
The standard 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 IEC 61400-25 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 IEC 61400-25 excludes information associated with feeders and substations. Substation communication is covered within the IEC 61850 series of standards.
The intention of IEC 61400-25 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 plants less time-consuming and more efficient. The standard supports scalability, connectivity, and interopera-bility
This standard 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 standard IEC 61400-25 is organised in several parts. Part IEC 61400-25-1 offers an introductory orientation, crucial requirements, and a modelling guide.
Remark: IEC 61400-25-2 (Information models) is mainly an extension of the Information Models of the International Standard IEC 61850-7-4 and -7-3.
IEC 61400-25 defines communication for monitoring and control of wind power plants. The modeling approach of IEC61400-25 (based on IEC 61850-7-3 and IEC 61850-7-4) has been selected to provide abstract definitions of classes and services such that the specifications are independent of specific protocol stacks, implementations, and operating systems. The mapping of these abstract classes and services to a specific communication profile is not inside the scope of this part (IEC 61400-25-2) but inside the scope of IEC 61400-25-4.
To reach interoperability, all data in the information model need a strong definition with regard to syntax and semantics. The semantics of the data is mainly provided by names assigned to logical nodes and data they contain, as defined in this part. Interoperability is easiest if as much as possible of the data are defined as mandatory.
It should be noted that data with full semantics is only one of the elements required to achieve interoperability. Since data and services are hosted by devices (IED), a proper device model is needed along with compatible domain specific services (see IEC 61400-25-3).
This part is used to specify the abstract definitions of a logical device class, logical node classes, data classes, and abstract common data classes. These abstract definitions shall be mapped into concrete object definitions that are to be used for a particular protocol.
The compatible logical node name and data name definitions found in this part and the associated semantics are fixed.
Remark: IEC 61400-25 DOES NOT provide interchangeability of devices!!
LN classes for a whole wind power plant:
LN classes for a wind turbine:
Use of instances of logical nodes
The logical node instances depicted represent information from wind turbines "WTUR", yawing system "WYAW", converter "WCNV", etc. The instance names, e.g. of WGEN1 and WGEN2 represent different generators. The figure below illustrates the interfacing electrical system including measurements "MMXU", circuit breakers "XCBR", etc. MMXU, XCBR and other logical nodes related to the electrical system are specified in IEC 61850-7-3.
The following ACSI servcies are referenced:
Overview of ACSI models and services are defined in IEC 61850-7-2:
Self-description services allow to retrieve the complete information model as it is implemented in a device. This allows to validate the information model. Any deviation from the model engineered some time ago would be figured out.
Value of data objects can easily be monitored for changes and limit violations. Analogue value monitoring and reporting is depicted below: limit violation (range and range configuration) and deadband monitoring.
Polling, Reporting and Logging:
Report example (according to IEC 61850-8-1 mapping):
Control a device:
The ACSI information exchange models are already implemented. Third party software is available.
Based on the comments received on the CDV IEC 61400-25-4 (doc 88/241/CDV), PT 61400-25 has recommended to specify more than one normative mapping. The mappings should be optional in order for the supplier and customer to agree on a solution that meets the needs for a certain monitoring and control application. At least one of the optional mappings shall be selected in order to be in conformance with the standard.
To meet the requirements of the wind power industry there are now five optional mappings under preparation:
The MMS mapping acording to IEC 61850-8-1 is already implemented. Third party software is available.
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 infor-mation 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 defi-nitions to specific communication profiles is defined in IEC 61400-25-4.
Part 6 defines the specific information models and information exchange models to be used by condition monitoring systems.
Note 1: The functions for condition monitoring, e.g., a specific analysis method for analysing the vibration sam-pled values are outside the scope of this part of the standard series. The standard series IEC 61400-25 deals with information and information exchange only.
The definitions in parts IEC 61400-25-1 to IEC 61400-25-5 (and IEC 61850-8-1) apply also for this part 6 of the standard series.
Condition monitoring relies mainly on the following kinds of information and the corresponding information exchange models:
1. waveform records (samples) of a specific time interval to be exchanged in real-time or by files for analysis (e.g. acceleration, position detection, stress detection)
2. status information and measurements (synchronized with the waveform records) represent-ing the Turbine Operation Conditions (TOC) of the same interval as for the waveform records; mainly to be used for the correct interpretation of the waveform and correlation. In-formation representing the TOC may also be used for many other purposes independent of waveform records.
3. results of waveform record analysis and analysis of TOC information (resulting, e.g., in analogue values, statistical values, historical (statistical) values, counters, status informa-tion, warnings and alarms)
The information consumed and generated by condition monitoring functions could 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 extra 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 infor-mation exchange services defined in IEC 61400-25-3/4 or defined/selected in this part 6.
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 compre-hensive 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. 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 informa-tion from the underlying CMD or TCD and may further process and analyse the measured val-ues and status information.
Note 2: The location of devices and functions (more centralized or decentralized topology) is outside the scope of this standard.
The information exchange between CMD and TCD as well as between the CMD and any other actor (e.g., SCADA systems) is specified in this standard. The information exchange com-prises mainly:
1. exchange of records of sampled values of waveform signals in real-time or by a file
Data objects and services for condition monitoring information:
The above figure depicts the basic functions of the CDC MV with regard to range monitoring. An analogue value could be in several ranges (normal, high, high-high or max). The ranges are configurable through the attribute “RangeConfig”. Any time when the value crosses a limit (canges the range) causes an event (trigger). These events can be used to issue a message (report) being sent to an IEC 61400-25 client using the report control blocks as defined in IEC 61400-25-3 (IEC 61850-7-2). The reporting model provides a mechanism to exchange any change of the value between any ranges. Additionally the range changes could be logged lo-cally in the server and retrieved later.
The dead banded value at time tn is sent to the client. A value change of +/- 10 per cent of the value (Min Max) issues another event to send the new value for time tn+1 etc.
The server may monitor the value for range changes and dead bands. The reports indicate the reason for inclusion (value change).
These values are RMS values (root mean square). In addition it is possible to calculate Mean values, MAX, MIN, etc. These statistical values can be archived in the server device. See IEC 61400-25-2 for statistical and historical statistical values.