Draft61850-7-1©1EC:2002 -11-57WG10-12(61850-7-1)R2-02/Draft FDIS 3 Terms and definitions Fur the purposes of this International Standard,the terms and definitions given in IEC 61850- 2 apply. 3.1 information Knowledge concerning objects,such as facts,events,things,processes,or ideas,including concepts, that within a certain context has a particular meaning.(IEV 101-12-01) 3.2 information model represents the knowledge concerning substation functions (devices)made visible and accessable through the means of IEC 61850.The model describes in an abstract way a simplified representation of a real function or device 3.3 model is a representation of some aspect of reality.The purpose of creating a model is to help understand, describe,or predict how things work in the real world by exploring a simplified representation of a par- ticular entity or phenomenon. 4 Abbreviated terms ACSI abstract communication service interface API application program interface CDC common data class CT current transformer IED intelligent electronic device LD logical device LN logical node LLNO logical node zero LPHD logical node physical device MMS Manufacturing Message Specification PHD physical device SCSM specific communication service mapping SoE sequence of events UML unified modelling language VT voltage transformer XML extended markup language Version Draft FDIS R2-02 2002-09-30:(08:00)
Draft 61850-7-1 IEC:2002 – 11 – 57/WG10-12(61850-7-1)R2-02 /Draft FDIS Version Draft FDIS R2-02 2002-09-30 : (08:00) 3 Terms and definitions Fur the purposes of this International Standard, the terms and definitions given in IEC 61850- 2 apply. 3.1 information Knowledge concerning objects, such as facts, events, things, processes, or ideas, including concepts, that within a certain context has a particular meaning. (IEV 101-12-01) 3.2 information model represents the knowledge concerning substation functions (devices) made visible and accessable through the means of IEC 61850. The model describes in an abstract way a simplified representation of a real function or device. 3.3 model is a representation of some aspect of reality. The purpose of creating a model is to help understand, describe, or predict how things work in the real world by exploring a simplified representation of a particular entity or phenomenon. 4 Abbreviated terms ACSI abstract communication service interface API application program interface CDC common data class CT current transformer IED intelligent electronic device LD logical device LN logical node LLN0 logical node zero LPHD logical node physical device MMS Manufacturing Message Specification PHD physical device SCSM specific communication service mapping SoE sequence of events UML unified modelling language VT voltage transformer XML extended markup language
Draft61850-7-1©1EC:2002 -12-57WG10-12(61850-7-1)R2-02/Draft FDIS 5 Overview of IEC 61850 concepts 5.1 Objective The parts IEC61850-7-4,IEC61850-7-3,IEC61850-7-2,IEC61850-6,and IEC61850-8-1are closely tied together.This clause provides an overview of these parts and it displays how these parts are interwoven. Each part defines an specific aspect of a substation IED: IEC 61850-7-4 defines specific information models for substation automation functions (e.g.,breaker with status of breaker position,settings for a protection function,...)- WHAT is modelled and could be exchanged, IEC 61850-7-3 has a list of commonly used information (e.g.,for double point control,3- phase measurand value,...)-WHAT is the common basic information, IEC 61850-7-2 provides the services to exchange information for the different kinds of functions(e.g.,control,report,get and set,..)-HOW to exchange information, IEC61850-6 offers the formal configuration description of a substation IED including the description of the relations with other IEDs-HOW to configure,and IEC 61850-8-1 defines the concrete means to communicate the information between IEDs (e.g.,the application layer,the encoding,...)-HOW to serialise the information during the exchange. 5.2 Topology and communication functions of substation automation systems As shown with the topology in Figure 2 one focus of IEC 61850 is the support of substation automation functions by the communication means of: sampled value exchange for CTs and VTs(1). fast exchange of l/O data for protection 1/O signals(2), control(3), engineering and configuration(4), monitoring and supervision(5), control-center communication(6). timesynchronisation Support for other functions like metering,condition monitoring,and asset management are supported as well. These functions are implemented in intelligent electronic devices (IED);various IEDs are shown in the figure.Several functions may be implemented in a single IED or one function may be implemented in one IEDs and another function may be hosted by another IED.IEDs (i.e.,the functions residing in IEDs)communicate with functions in other IEDs by the informa- tion exchange mechanisms of this standard. Version Draft FDIS R2-02 2002-09-30:(08:00)
Draft 61850-7-1 IEC:2002 – 12 – 57/WG10-12(61850-7-1)R2-02 /Draft FDIS Version Draft FDIS R2-02 2002-09-30 : (08:00) 5 Overview of IEC 61850 concepts 5.1 Objective The parts IEC 61850-7-4, IEC 61850-7-3, IEC 61850-7-2, IEC61850-6, and IEC 61850-8-1 are closely tied together. This clause provides an overview of these parts and it displays how these parts are interwoven. Each part defines an specific aspect of a substation IED: — IEC 61850-7-4 defines specific information models for substation automation functions (e.g., breaker with status of breaker position, settings for a protection function, ...) – WHAT is modelled and could be exchanged, — IEC 61850-7-3 has a list of commonly used information (e.g., for double point control, 3- phase measurand value, ...) – WHAT is the common basic information, — IEC 61850-7-2 provides the services to exchange information for the different kinds of functions (e.g., control, report, get and set, ...) – HOW to exchange information, — IEC61850-6 offers the formal configuration description of a substation IED including the description of the relations with other IEDs – HOW to configure, and — IEC 61850-8-1 defines the concrete means to communicate the information between IEDs (e.g., the application layer, the encoding, ...) – HOW to serialise the information during the exchange. 5.2 Topology and communication functions of substation automation systems As shown with the topology in Figure 2 one focus of IEC 61850 is the support of substation automation functions by the communication means of: – sampled value exchange for CTs and VTs (1), – fast exchange of I/O data for protection I/O signals (2), – control (3), – engineering and configuration (4), – monitoring and supervision (5), – control-center communication (6), – timesynchronisation – ... Support for other functions like metering, condition monitoring, and asset management are supported as well. These functions are implemented in intelligent electronic devices (IED); various IEDs are shown in the figure. Several functions may be implemented in a single IED or one function may be implemented in one IEDs and another function may be hosted by another IED. IEDs (i.e., the functions residing in IEDs) communicate with functions in other IEDs by the information exchange mechanisms of this standard
Draft61850-7-1©1EC:2002 -13-57WG10-12(61850-7-1)R2-02/Draft FDIS Control HMI Engineering Center othe other Station Bus other devics Ethernet Switch 2 ■■■ Bay Relay Relay Bay Relay Relay Controller A B Controller A E Process Bus ③ Modern Modern Modern Modern Switchgear CT/VT Switchgear CT/VT Figure 1-Sample substation automation topology 5.3 The information models of substation automation systems The information exchange mechanisms rely primarily on the well defined information models. These information models and the modelling methods are the core of IEC 61850.IEC 61850 uses the approach to model the common information found in real devices as depicted in Fig- ure 2.All information made available to be exchanged with other devices is defined in the standard. NOTE 1 "The common information"in the context of IEC 61850 means that the stakeholders of substation automation systems(users and vendors)have agreed that the information defined in IEC 61850 is widely accepted and required for the open exchange of information between any kind of substation IEDs. logical device(Bay) 61850-7-2 (Virtual World) virtualisation Services TCP/IP MMS N -Network) XCBR1 SCSM 61850-8-1 Mode Real devices in any 61850-7-4 logical node substation 61850-7-4data (circuit breaker) (Position) 61850-6 1850 configuration file Figure 2-Modelling approach(conceptual) Version Draft FDIS R2-02 2002-09-30:(08:00)
Draft 61850-7-1 IEC:2002 – 13 – 57/WG10-12(61850-7-1)R2-02 /Draft FDIS Version Draft FDIS R2-02 2002-09-30 : (08:00) Control Center HMI Engineering Ethernet Switch Router Station Bus Relay A Bay Controller Modern Switchgear Modern CT / VT Relay B Relay A Bay Controller Modern Switchgear Modern CT / VT Relay B Process Bus other other devics other devics devics 1 3 2 5 4 6 Figure 1 – Sample substation automation topology 5.3 The information models of substation automation systems The information exchange mechanisms rely primarily on the well defined information models. These information models and the modelling methods are the core of IEC 61850. IEC 61850 uses the approach to model the common information found in real devices as depicted in Figure 2. All information made available to be exchanged with other devices is defined in the standard. NOTE 1 “The common information” in the context of IEC 61850 means that the stakeholders of substation automation systems (users and vendors) have agreed that the information defined in IEC 61850 is widely accepted and required for the open exchange of information between any kind of substation IEDs. Hides/encapsulates real World Mapping ... (Virtual World) LN LN LN Position SCSM 61850-8-1 TCP/IP Network MMS 61850-7-2 Services logical device (Bay) Mode XCBR1 61850-7-4 logical node (circuit breaker) 61850-7-4 data (Position) virtualisation Real devices in any substation 61850-6 configuration file Figure 2 – Modelling approach (conceptual)
Draft61850-7-1©1EC:2002 -14-57WG10-12(61850-7-1)R2-02/Draft FDIS The standard defines the information and information exchange in a way that it is independent of a concrete implementation (abstract models).The standard uses also the concept of virtu- alisation.The virtualisation provides a view of those aspects of a real device that are of inter- est for the information exchange with other devices.Only those details are defined in IEC 61850 that are required to provide interoperability of devices. As described in IEC 61850-5,the approach of the standard is to decompose the application functions into the smallest entities,which are used to exchange information with.The granu- larity is given by a reasonable distributed allocation of these entities to dedicated devices (IED).These entities are called logical nodes (e.g.,a virtual representation of a circuit breaker,with the standardised name XCBR).The logical nodes are modelled and defined from the conceptual application point of view in IEC 61850-5.Several logical nodes build a logical device (e.g.,a representation of a Bay unit).A logical device shall be implemented in one IED;therefore logical devices are not distributed. Real devices on the right hand side are modelled as a virtual model in the middle of the fig- ure.The logical nodes defined in the logical device (Bay)correspond to well known functions in the real devices.In this example the logical node XCBR represents a specific circuit breaker of the bay to the right. NOTE 2 The logical nodes of this example may be implemented in one or several IEDs as appropriate.In case the logical nodes are implemented in different IEDs they need exchange information over a network.Informa- tion exchange inside a logical node is outside the scope of IEC 61850. Based on their functionality,a logical node contains a list of data (e.g.,Position)with dedi- cated data attributes.The data have a structure and a well-defined semantic (meaning in the context of substation automation systems).The information represented by the data and their attributes are exchanged by the services according well-defined rules and the requested per- formance as described in IEC 61850-5.The services are implemented by a specific and con- crete communication means(SCSM,e.g.,using MMS,TCP/IP,and Ethernet among others). The logical nodes and the data contained in the logical nodes are crucial for the description and information exchange for substation automation systems The logical devices,the logical nodes and the data they contain need to be configured.The main reason for the configuration is to select the appropriate logical nodes and data from the standard and to assign the instance-specific values,e.g.,concrete references between in- stances of the logical nodes (their data)and the exchange mechanisms,and initial values for process data. 5.4 Applications modelled by logical nodes defined in 61850-7-4 Table 2 lists all groups of logical nodes defined in IEC 61850-7-4.Some 90 logical nodes covering the most common applications of substation automation systems are defined.One main focus is the definition of information models for protection and protection related appli- cations(38 logical nodes out of 88).These two groups cover nearly half of the logical nodes. Version Draft FDIS R2-02 2002-09-30:(08:00)
Draft 61850-7-1 IEC:2002 – 14 – 57/WG10-12(61850-7-1)R2-02 /Draft FDIS Version Draft FDIS R2-02 2002-09-30 : (08:00) The standard defines the information and information exchange in a way that it is independent of a concrete implementation (abstract models). The standard uses also the concept of virtualisation. The virtualisation provides a view of those aspects of a real device that are of interest for the information exchange with other devices. Only those details are defined in IEC 61850 that are required to provide interoperability of devices. As described in IEC 61850-5, the approach of the standard is to decompose the application functions into the smallest entities, which are used to exchange information with. The granularity is given by a reasonable distributed allocation of these entities to dedicated devices (IED). These entities are called logical nodes (e.g., a virtual representation of a circuit breaker, with the standardised name XCBR). The logical nodes are modelled and defined from the conceptual application point of view in IEC 61850-5. Several logical nodes build a logical device (e.g., a representation of a Bay unit). A logical device shall be implemented in one IED; therefore logical devices are not distributed. Real devices on the right hand side are modelled as a virtual model in the middle of the figure. The logical nodes defined in the logical device (Bay) correspond to well known functions in the real devices. In this example the logical node XCBR represents a specific circuit breaker of the bay to the right. NOTE 2 The logical nodes of this example may be implemented in one or several IEDs as appropriate. In case the logical nodes are implemented in different IEDs they need exchange information over a network. Information exchange inside a logical node is outside the scope of IEC 61850. Based on their functionality, a logical node contains a list of data (e.g., Position) with dedicated data attributes. The data have a structure and a well-defined semantic (meaning in the context of substation automation systems). The information represented by the data and their attributes are exchanged by the services according well-defined rules and the requested performance as described in IEC 61850-5. The services are implemented by a specific and concrete communication means (SCSM, e.g., using MMS, TCP/IP, and Ethernet among others). The logical nodes and the data contained in the logical nodes are crucial for the description and information exchange for substation automation systems. The logical devices, the logical nodes and the data they contain need to be configured. The main reason for the configuration is to select the appropriate logical nodes and data from the standard and to assign the instance-specific values, e.g., concrete references between instances of the logical nodes (their data) and the exchange mechanisms, and initial values for process data. 5.4 Applications modelled by logical nodes defined in 61850-7-4 Table 2 lists all groups of logical nodes defined in IEC 61850-7-4. Some 90 logical nodes covering the most common applications of substation automation systems are defined. One main focus is the definition of information models for protection and protection related applications (38 logical nodes out of 88). These two groups cover nearly half of the logical nodes
Draft61850-7-1©1EC:2002 -15-57WG10-12(61850-7-1)R2-02/Draft FDIS Table 2-LN groups Logical node groups Number of logical nodes System logical nodes 2 Protection functions 28 Protection related functions 10 Supervisory control 5 Generic references ⊙ Interfacing and archiving 4 Automatic control 4 Metering and measurement 7 Sensors and monitoring 3 Switchgear 2 Instrument transformer 2 Power transformer Further power system equipment 14 88 IEC 61850 has well-defined rules to define additional logical nodes,e.g.,for additional func- tions within substations or for other application domains like wind power plants.For details on the extension rules see clause 14 Name spaces. The following excerpt of the logical nodes has been included just to give a flavour what kind of real applications the logical nodes represent: 一 Basic Protection Relay Directional element Harmonic restraint Protection Scheme Transient Earth Fault Zero speed or underspeed Distance protection 一 Volts per Hz relay 一 Undervoltage Directional over power 一 Measurement Metering Sequence and Imbalance Harmonics and Interharmonics Differential Measurements Circuit breaker Circuit Switch Most logical nodes provide information that can be categorised as depicted in Figure 3. Version Draft FDIS R2-02 2002-09-30:(08:00)
Draft 61850-7-1 IEC:2002 – 15 – 57/WG10-12(61850-7-1)R2-02 /Draft FDIS Version Draft FDIS R2-02 2002-09-30 : (08:00) Table 2 – LN groups Logical node groups Number of logical nodes System logical nodes 2 Protection functions 28 Protection related functions 10 Supervisory control 5 Generic references 3 Interfacing and archiving 4 Automatic control 4 Metering and measurement 7 Sensors and monitoring 3 Switchgear 2 Instrument transformer 2 Power transformer 4 Further power system equipment 14 88 IEC 61850 has well-defined rules to define additional logical nodes, e.g., for additional functions within substations or for other application domains like wind power plants. For details on the extension rules see clause 14 Name spaces. The following excerpt of the logical nodes has been included just to give a flavour what kind of real applications the logical nodes represent: — Basic Protection Relay — Directional element — Harmonic restraint — Protection Scheme — Transient Earth Fault — Zero speed or underspeed — Distance protection — Volts per Hz relay — Undervoltage — Directional over power — ... — Measurement — Metering — Sequence and Imbalance — Harmonics and Interharmonics — Differential Measurements — ... — Circuit breaker — Circuit Switch — ... Most logical nodes provide information that can be categorised as depicted in Figure 3