Notes on IEC61400-25, IEC61850 and IEC60870-5
IEC61400-25
IEC61400-25 is a standard describing communication between SCADA systems and wind power plants/turbines. It also fully describes the data-objects a wind power plant/turbine MUST (the mandatory data) and MAY (the optional data) expose.
In large parts IEC61400-25 extends or builds upon the Information Model (IM) and Information Exchange Model (IEM) standardized in IEC61850-7.
To get a relatively complete overview of the main idea of the standard and the content of the main parts, chapter 5-8 in 25-1 should be read (approximately 20 pages).
IEC61400-25 Parts
- 25-2 Information Model (IM) describes a full object model that wind power plants/turbines must expose to comply with IEC61400-25.
- on the mindmap the classes in the object model is seen in the mid-bottom:
- A server contains a number of logical devices, each consisting of a number of logical nodes, each containing a number of data values and attributes.
- Annex D from 25-2 lists the logical nodes that are mandatory.
- It should be noted that the IM in IEC61400-25-2 is not a completely self-contained model. Quite a few of the logical nodes and datatypes are just references to content described in IEC61850-7.
- on the mindmap the classes in the object model is seen in the mid-bottom:
- 25-3 Information Exchange Model (IEM) describes an abstract communication model. On the mindmap it is seen how this defines a number of operations, listed in the box on the left: ACSI - Abstract Communication Service Interface and detailed below.
- For IEC61400-25-3 it should also be noted that the IEM is not completely self-contained. Quite a few details of the services are references to content described in IEC61850-7.
- 25-4 IEM Mapping to Communication Profile describes 5 different actual implementations of the IEM.
- Mapping A is a full webservice (WS) implementation of the IEM.
- Mapping B is a partly implementation using OPC-XML-DA.
- Mapping C is a fully compliant implementation using MMS (a communication and encoding standard described in ISO9506 and IEC61850-8).
- Mapping D is a partly implementation using IEC60870-5-104 (see further description below). One of the missing features in this mapping is that there is no support for the discovery services, meaning that the client must get a full configuration “out-of-band”.
- Mapping E is a fully compliant implementation using DNP3 standardized in IEEE1815.
IEC61850
- IEC 61850
- News on IEC 61850 blog on “IEC 61850 and related Standards” (IEC 61850, IEC 61400-25, IEC 61970 (CIM), IEC 60870-5, DNP3, IEC 62351) by one of the authors of the standards.
Is a set of standards related to the design and communication with automation of electrical substations.
The idea of an Information Model (IM) and an Information Exchange Model (IEM) with a set of abstract ACSI services is something IEC61400-25 borrows from this IEC61850-7 standard.
IEC60870-5
Is an old set of standards for telecontrol systems in power system automation.
Mostly relevant is the newer 10x parts:
- 5-101 Transmission Protocol defines the full communication stack for seriel(?) communication with 3 layers:
- application: On this layer a set of basic tasks/functions are defined. Examples of the types of functions are given in the box on the right of the mindmap.
- link: On this layer the low level packets (ASDU), encoding (BER) and addressing (IOA) are defined.
- physical.
- 5-104 Transmission Protocol using TCP/IP. Is is assumed that this basically describes how the link layer ASCU packets are encoded as TCP/IP packages.