What is a Logical Node? - NettedAutomation GmbH

1 what is a Logical Node? By Karlheinz Schwarz, SCC, Motivation The standard IEC 61850 Communication networks and systems in substations and the coming standard IEC 61400-25 Communications for monitoring and control of wind power plants use the concept of Logical Nodes (LN) as a key element to define the information of a device to be communicated. This paper introduces the concept of LNs. Modeling Key issues are the LNs representing functions or equipment used in power systems. Each concept LN provides a list of well organized and named information. The LN XCBR5 represents the circuit breaker number 5 with the data Pos (Position) and Mode . Services defined in IEC 61850-7-2 allow the exchange of this information (Client/Server, GOOSE, SV, ).

2 IEC 61850 Logical device ( a Bay). models substation equipment and func- IEC 61850-7-2 (Virtual World) virtualisation Services tions (focus is on protection). GOOSE. Mapping Network SV. IEC 61400-25 LN. models components TCP/IP. LN LN. MMS. of wind power plants Network XCBR5. IEC 62344. models components SCSM. Pos of hydro power IEC 61850-8-1 Mode plants (-9-1 / -9-2) .. Real devices in a IEC 62350 IEC 61850-7-4 Logical IEC 61850-7-4. substation models components node (circuit breaker) data (Position). of decentgralized en- ergy resources (DER). IEC 61850-6. IEC 61850 configuration file, XML. extensions model more monitoring data The substation configuration language in part 6 supports the engineering process.

3 Example LN The measurement LN MMXU represents power, voltages, currents, and impedances in a MMXU three-phase system. The values can be communicated by various services Logical Node MMXU . Read Read TotW deadbanded Total Active Power (Total P) value angle (Total Q). TotVAr Total Reactive Power Total Apparent Power (Total S). TotVA IEC 61850-7-4 Report Report RCB. RCB Average Power factor (Total PF). TotPF defines some Hz Frequency 90 LNs QueryLog PPV Phase to phase voltages (VL1VL2, ). QueryLog Log 500 Data Log PhV Phase to ground voltages (VL1ER, ). 100 Attributes A Phase currents (IL1, IL2, IL3). 10 Service models Configure Configure W Phase active power (P). VAr Phase reactive power (Q). IEC 61400-25.

4 VA Phase apparent power (S). adds some Retrieve Retrieve PF Phase power factor 10 LNs Model Model Z Phase Impedance 200 Data IEC 61850-7-2. 100 Attributes SV. SV. SV. SV. current / voltage samples from instrument IEC 61850-7-2. transformers represented by LN PhsBTCTR for current transformer of phase B ( by sampled LN. LNPhsBTCTR. PhsBTCTR LN. LNPhsBTVTR. PhsBTVTR. Amp Vol value exchange services of IEC 61850-7-2 SV) Amp Vol The MMXU LN offers hundreds of values: measured (process) values, configuration val- ues, description, and substitution values. These values can be communicated by various services like read (polling), notification (publish/subscribe), logging and query. SCC Revision 0 3 2004 08 12