Standards Development

Scope

1.1 General

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 outside the scope of the IEC 61400-25 series.

The IEC 61400-25 series is based on the IEC 61850 and 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.

- 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 standard excludes a definition of how and where to implement the communication interface, the application program interface and implementation recommendations. However, the objective of the standard 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 61400-25-2 specifies the information model of devices and functions related to wind power plant applications. In particular, it specifies the compatible logical node names, and data names for communication between wind power plant components. This includes the relationship between logical devices, logical nodes and data. The names defined in the IEC 61400-25 series are used to build the hierarchical object references applied for communicating with components in wind power plants.

This part of IEC 61400-25 specifies common attribute types and common data classes related to wind turbine applications. In particular, it specifies common data classes for:

- setpoint value,

- status value,

- alarm,

- command,

- event counting,

- state timing,

- alarm set status.

(Please see draft for table) Communication model of the IEC 61400-25 series Client Server Information exchange model (get, set, report, log, control, publish / subscribe, etc.) defined in IEC 61400-25-3 Information exchange model (get, set, report, log, control, publish / subscribe, etc.) defined in IEC 61400-25-3 Wind power plant information model (rotor speed, break status, total power production, etc.) defined in IEC 61400-25-2 Wind power plant information model (rotor speed, break status, total power production, etc.) defined in IEC 61400-25-2 Wind power plant component e.g. wind turbine Application Application Actor e.g. SCADA Messaging through mapping to communication profile (Read, write, ... message) defined in IEC 61400-25-4 Messaging through mapping to communication profile (Read, write, ... message) defined in IEC 61400-25-4 Information exchange model (get, set, report, log, control, publish / subscribe, etc.) defined in IEC 61400-25-3 Information exchange model (get, set, report, log, control, publish / subscribe, etc.) defined in IEC 61400-25-3 Wind power plant information model defined in IEC 61400-25-2 Wind power plant information model defined in IEC 61400-25-2 Outside scope Outside scope Figure 1 – Conceptual communication model of the IEC 61400-25 series

Devices implementing the information model of this part shall choose one or more logical nodes as required by the application.

NOTE 1 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 or by user groups.

NOTE 2 This part does not provide tutorial material.

1.2 Data model Namespace name and version

This new subclause is mandatory for any IEC 61850 namespace (as defined by IEC 61850-7- 1).

Table 2 shows all attributes of IEC 61400-25-2:2021A namespace.

Table 2 – Attributes of IEC 61400-25-2:2021A namespace (Please see draft for table)

1.3 Data model Namespace Code Component distribution

The Code Components are in light and full version:

• The full version is named : IEC_61400-25-2.NSD.2021A.Full.It contains definition of the whole data model defined in this standard with the documentation associated and access is restricted to purchaser of this part

• The light version is named : IEC_61400-25-2.NSD.2021A.Light. It doesn't contain any documentations but contains the whole data model as per full version, and this light version is freely accessible on the IEC website for download at : http://www.iec.ch/tc57/supportdocuments, but the usage remains under the licensing conditions.

The Code Components for IEC 61850 data models are formated in compliance with the NSD format defined by the standard IEC 61850-7-7. Each Code Component is a ZIP package containing :

• the electronic representation of the Code Component itself (possibly multiple files),

• the grammar files (XSD) enabling to check the consistency of the associated files against the defined version of NSD, but as well against the IEC 61850 flexibility rules in case of private extensions

• a file describing the content of the package (IECManifest.xml).

The IEC Manifest contains different sections giving information on:

• The copyright notice

• The identification of the code component

• The publication related to the code component

• The list of the electronic files which compose the code component

• An optional list of history files to track changes during the evolution process of the code component

The life cycle of a code component is not restricted to the life cycle of the related publication. The publication life cycle goes through two stages, Version (corresponding to an edition) and Revision (corresponding to an amendment). A third publication stage (Release) allows publication of Code Component in case of urgent fixes of InterOp Tissues, thus without need to publish an amendment. Consequently new release(s) of the Code Component may be released, which supersede(s) the previous release, and will be distributed through the IEC TC57 web site at: http://www.iec.ch/tc57/supportdocuments. The latest version/release of the document will be found by selecting the file named IEC_61400- 25-2.NSD.{VersionStateInfo}.Light with the filed VersionStateInfo of the highest value.