Introduction and Overview of IEC Communications. Schweitzer Engineering Laboratories, Inc.

Transcription

1 Introduction and Overview of IEC Communications Schweitzer Engineering Laboratories, Inc. Copyright SEL 2009

2 SEL Provides Integration Best Practice & Stand-Alone IED Protocols SEL Suite SMART - SEL Metering, Automation and Remote Telecommunications SEL Fast Message, SEL MIRRORED BITS, Interleaved ASCII SCADA - DNP3, Modbus, IEC /104, legacy, etc.

3 SEL Provides Integration Best Practice & Stand-Alone IED Protocols Global Ethernet tools - FTP, Telnet, Ping Suite of IEC Protocols MMS similar to FM, DNP3 GOOSE - discrete data and measured analogs similar to SEL MIRRORED BITS Sampled Values (SV) raw analog measurements XML based Substation Configuration Language (SCL) similar to SEL auto-configuration

4 SMART Protocol Suite Satisfies Each Substation Automation Requirement Discovery of IED contents Communications configuration Polling of IED data by a data consumer Reporting of data from IEDs Unsolicited text messaging Commanded or automatic control of IED Peer-to-peer messaging between IEDs Digitized instrument transformer values Time synchronization Configuration revision management Engineering access Alarm callout, dialback Communications diagnostics Local and wide area synchrophasors

5 Users Wanted to Replace SCADA Communications With Networked IEDs Standardized protocol Self-describing devices International adoption Reduction in obsolescence Support for multiple functions in one device Based upon commonly available technology

6 IEC Standard Satisfies The Wants Dictionary of power and communication terms; each vendor uses the same dialect Object-oriented database structures Combination of protocols for different needs Client/server replaces traditional master/slave Publish/subscribe multicasts

7 Replace Field Wiring With Ethernet LANs Signal List Object List LN XCBR LN IHMI LN CSWI Circuit Breaker Station HMI Switch Controller Move data with same methods from each manufacturers devices Group data logically Create, find, and use data with standardized methods

8 Replace Field Wiring With Ethernet LANs Signal List Object List LN XCBR LN IHMI LN CSWI Circuit Breaker Station HMI Switch Controller Simplify communications using network methods Communicate with coexisting Ethernet conversations Apply familiar Internet methods

9 Substation Configuration Language (SCL) Provides Dictionary, Descriptions

10 SCL Includes Processes for Finding, Describing, Classifying, Naming Data SCL Classification Station: Voltage level: Oasis 220 kv Bay: Bay 1 Apparatus: Physical Device: Logical Device:* Logical Node (LN):* Circuit breaker SEL-421 Meter (MET) Measurements (MMXU) LN Instance:* First measurement group (1) Function:* Data Object:* Analog measurement (MX) Frequency (HZ) *Dictated by the standard Data name = MET.MMXU1.MX.HZ

11 SCL Taxonomy Used to Name IED Data Within the Devices Functional Constraints Data Objects A Hz MX MX Logical Nodes MMXU1 MMXU2 Logical Device MET (e.g. PRO, CON, ANN) Physical Device (SEL-421 IP Address) Virtual View of Relay Data Map METMMXU2$MX$Hz = Breaker #1 Frequency Measurements

12 Custom Prefixes Combined With Standardized Naming Provide Intuitive Description Data Object Data Attributes q stval Pos Pos Logical Nodes XCBR1 XCBR1 Logical Device LVD97010MCADCTRL1 Physical Device LVD97010MCAD (network address) LVD97010MCAD.LVD97010MCADCTRL1.XCBR1.Pos.stVal = Status value of position of circuit breaker #1

13 IED Data Naming Within the Devices Also Used On the Wire and In Clients Data names are explicit and aid browsing data within a SEL-421

14 61850 Groups Data by Function, Groups Called Logical Nodes

15 Each IED has Several Logical Devices, Each With Multiple Logical Nodes

16 IEC A Suite of Protocols; Not Just One Sampled Values (Multicast) Generic Object- Oriented Substation Event Time Sync (Method 2) Core ACSI Services Generic Substation Status Event Time Sync (Method 1) SV (Type 4) GOOSE (Type 1, 1A) Time Sync (SNTP) (Type 6) MMS Protocol Suite (Type 2, 3, 5) GSSE (Type 1, 1A) GPS IRIG-B UDP/IP GSSE T-Profile ISO/IEC Ethertype ISO/IEC

17 IEC Addresses More Substation Automation Elements Than SCADA Methods 1. Local and system automation 2. Discovery of IED contents* 3. Communications configuration* 4. Polling of IED data by a data client* 9. Digitized instrument transformer values* 10. Time synchronization* 11. Configuration revision management 12. Engineering access 5. Reporting of data from IEDs* 6. Unsolicited text messaging 7. Commanded or automatic control of IED* 8. Peer-to-peer messaging between IEDs* 13. Alarm callout, dialback 14. Communications diagnostics 15. Local and wide area synchrophasors * Addressed by IEC 61850

18 Features and Attributes of IEC Support Networked IED Applications MMS protocol for polling, reporting, self description, and file transfer GOOSE protocol, sampled value (SV) protocol, and substation configuration language (SCL) Coexistence/compatibility with Telnet, FTP, other Ethernet-based protocols like SEL, IEEE C37.118

19 Routed and Nonrouted Protocols Use Different Address Types Nonrouted David Dolezilek 2350 NE Hopkins Ct SMART, DNP3, Modbus Internet routed Occupant 2350 NE Hopkins Ct MMS, FTP, Telnet Intranet multicast GOOSE, SV Each doorstep on the route

20 Nonrouted Messages are Authenticated by Physical Address and Name

21 Internet WAN Routed Messages are Delivered to Network Address IEC MMS, Tunneled SEL Fast Messages, Tunneled SEL Mirrored Bits, DNP3 IP, , Modbus TCP, other SCADA protocols

22 Internet WAN Routed Messages are Delivered to Network Address

23 Intranet LAN Multicast Messages Delivered to Everyone on the Intranet IEC GOOSE, IEC SV

24 Goose and SV are Published to a Group Address, Anyone Can Subscribe

25 Intranet LAN Routed Messages Delivered to Whoever Will Listen on the Intranet Without WAN Routing Layer, GOOSE and SV get rejected at the WAN router

26 Client Server Supports What You Want When You Want On demand or on data change Polling, reporting, ad-hoc

27 Like SMART, MMS Retrieves One Piece of Information or Entire Report

28 Constant Repetition Serves Sampled Data and GOOSE Integrity Heartbeat Predictable receipt Constant bandwidth utilization GOOSE Heartbeat Messages, SV, Time Synch

29 Faster Repetition Increases Likelihood That Change Will be Noticed Quickly Increased bandwidth use only after change Interrupt driven GOOSE Datachange Messages Slows to constant repetition

30 SVs Publish at Fixed Rate Separate sampling physically from Measurement Metering Calculation Multiple subscribers to each SV

31 IEC LE Sampled Values Fixed Rate Publication Requirements Sampling Protection: 4, 4.8 khz Quality metering: 12.8, khz Publication Protection: 4, 4.8 khz (one sample per message) Quality metering 1.6, 1.92 khz (eight samples per message)

32 Required LAN Behavior of GOOSE and SV Led to Differences From MMS GOOSE, SV Publish/subscribe Multicast to multiple consumers IP not fast enough No IP, no network layer, no transport layer; therefore, no addressing Not routable, multicast to many consumers on local LAN MMS Client/server Unicast to one specific consumer IP is fast enough and provides transport layer and network layer Network layer provides addressing Addressing makes MMS routable to consumer on LAN or WAN

33 MMS Client Server Applications Are Unaware When Transport Layers Restore Lost Data Workstation H E L L O TCP Retransmission and Reassembly Data L Retransmitted Server H E L L O Data H Data E Data X L Data L Data O HELO

34 Like SEL MIRRORED BITS Before Them, GOOSE and SV Replace Copper With Fiber SEL Confidential

35 GOOSE and SV Applications Survive When Data Are Lost Workstation Server No resend, next message already on its way To get this behavior, we have no network layer, and therefore no WAN routing Data 1 Data 2 Data 3 Data 4 Data 5 Lost Data With Sequence #3

36 IEC GOOSE and SV Custom Ethertypes Registered by IEEE Ethertypes Determine the Network Layer Connection Use IEC GOOSE 88-B8 IEC GSE Management 88-B9 IEC Sampled Values IEC MMS via IP 88-BA Ethertype Value (hexadecimal) [Ethertype for all IP traffic]

37 Same GOOSE Message Sent Repetitively as Hold Time Expires Until Data Change Dataset Change 1. Calculate New Hold Time 2. Start Hold Timer 3. Increment Sequence Number Retransmit- Pending New State: 1. Set Sequence Number = 0 2. Increment State Number 3. Reset Hold Timer = Maximum Delay Time Hold Timer Expired Send Message

38 Time Between Publications Changes to Improve Likelihood it Will Get Through After dataset change, publisher multicasts with ttl = T1 (variable set to low value) to increase likelihood that subscribers will hear Publishers gradually increases ttl until it = Max Time setting

39 Dataset Change Due to Discrete Inputs and Logic Changing State

40 Dataset Change Due to Analog Value Changing by More Than Deadband (DB) Value will not be reported until it changes by more than the db value db is a % of the full scale value

41 Transfer Time Includes Time to Detect, Transfer, and Process Change

42 Time Between Publications Changes Publishers calculate and report time to live (ttl) with dataset Publishers multicast next message after delay = ttl if there is no dataset change Subscribers constantly calculate time to wait (ttw), based on ttl within each message

43 Receiver Uses TTL to Detect Communications Problem Subscriber considers data stale when time to wait expires Publisher IED fails Cable broken Switch failed Publisher sends new message on data change without waiting entire time delay

44 Modify Communications Aided Schemes When Communications Fail Differentiate between silence and failed communications Adapt to failed remote tripping, interlocking, blocking Set alarms, warn others, request maintenance

45 Priority Queuing and VLAN Segregation Organize Ethernet Traffic Destination Address Source Address Tag Type Data TPID = 0 x bit type identifier (constant) x x x 0 3-bit priority field 0 x XXX 12-bit VLAN identifier IEEE 802.1p priority IEEE 802.1q segregation

46 Physical Devices (PDs) Contain LN Data Which Must be Exchanged Via Ethernet PD4 LN2 LN8 PD1 LN3 LN9 LN1 LN4 LN5 LN7 LN6 PD2 PD3 PD1 Station Computer PD2 Sync Relay PD3 Bay Control PD4 Distance,OC Relay

47 Applications Require Logical Association Between Logical Nodes PD4 LN2 LN8 PD1 LN3 LN9 PD2 LN1 LN4 LN5 LN7 PD3 LN6

48 Logical Nodes Combine to Create Functions Logical Nodes HMI (IHMI) Synchronized CB Switching Functions F1 F2 F3 Distance Protection Overcurrent Protection LN1 LN2 LN3 PD1 Synch Check (RSYN) Breaker (XCBR) Distance Protection (PDIS) LN4 LN5 LN6 LN8 LN7 PD2 PD3 PD4 Physical Devices Overcurrent Protection (PTOC) LN9

49 Functions (F) Often Logically Connect Several Physical Devices LN2 F2 PD4 LN8 PD1 LN3 LN9 PD2 LN1 LN4 F1 F3 LN5 LN7 PD3 LN6

50 Additional Physical Device, Same Functions Logical Nodes HMI (IHMI) Synchronized CB Switching Functions F1 F2 F3 Distance Protection Overcurrent Protection LN1 LN2 LN3 PD1 Synch Check (RSYN) Breaker (XCBR) Distance Protection (PDIS) LN4 LN5 LN6 LN8 LN7 PD2 PD3 PD4 Physical Devices Overcurrent Protection (PTOC) LN9 PD5

51 Same Functions, Different Logical Node Allocation LN2 F2 PD4 LN8 PD1 PD5 LN3 LN9 LN1 F3 F1 LN7 LN6 PD2 LN4 LN5 PD3 PD1 Station Computer PD2 Sync Relay PD3 Bay Control PD4 Distance Relay PD5 OC Relay

52 Data are Segregated Based on Functions Via VLAN Tags on Messages LN2 F2 PD4 LN8 PD1 PD5 LN3 LN9 LN1 F1 F3 LN7 LN6 F1 VLAN 1, PD1, PD2, PD3 F2 VLAN 2, PD1, PD3, PD4 F3 VLAN 3, PD1, PD3, PD5 LN4 LN5 PD2 PD3 Devices listen to only the messages necessary to participate in a function

53 Biggest Difference Between UCA and IEC is SCL File Configuration System Specification Description (SSD) power system functions Substation Configuration Description (SCD) complete substation communications map IED Capability Description (ICD) default data reported by a type of IED Configured IED Description (CID) custom configuration of a specific IED

54 System Specification Description System Specification Tool SSD File Library The system specification description file (.ssd) describes the single-line diagram and the substation automation functionality using the associated logical nodes Single-line diagram connections Logical nodes, logical node types

55 SSD: One-Line and Functions PTOC TCTR MMXU XCBR XSWI CSWI CSWI CILO YLTC ATCC PTOC TCTR MMXU XCBR XSWI CSWI CSWI CILO YLTC ATCC IHMI ITCI Bay =Q1 Bay =Q2 Station Computer NCC Gateway PTOC TCTR MMXU XCBR XSWI CSWI CSWI CILO YLTC ATCC PTOC TCTR MMXU XCBR XSWI CSWI CSWI CILO YLTC ATCC IHMI ITCI Bay =Q1 Bay =Q2 Station Computer NCC Gateway

56 IED Capability Description IED Configuration Tool ICD File The IED capability description file (.icd) describes the capabilities and (optionally) the preconfigured data model of the IED Logical devices, logical nodes, logical node types Data sets Library Control blocks not populated Think of it as an Default IED template

57 ICD: Map IEDs to Logical Devices Station Computer IHMI IHMI NCC Gateway Switch Switch Bay Switch Bay Switch Controller Switch IED Controller XSWI CSWI XSWI CSWI CILO Breaker IED CILO XCBR CSWI XCBR CSWI MMXU MU Switch MMXU TCTR PTOC TCTR PTOC Protection Protection YLTC ATCC YLTC ATCC Tap changer Controller Transformer IED Tap ch. Contr.

58 System Configuration Description SSD File SCD File ICD File ICD File ICD File ICD File System Configuration Tool The substation configuration description file (.scd) describes the complete substation configuration Single-line diagram Communication network IED configurations Binding information (e.g., trip matrix)

59 SCD: Add the Communications Bay Switch IED XSWI Process level bus segments CSWI CILO Station level and interbay Bus, e.g., ring Breaker IED CSWI XCBR XCBR Switch MMXU MU ATCC TCTR TCTR TvTR TVTR Controller PTOC Protection 1 Switch YLTC Switch PTOC Transformer IED Protection 2

60 Configured IED Description SCD File Or ICD File IED Configuration Tool CID File The configured IED description file (.cid) describes customized configuration parameters for specific IED (Feeder #1, Oasis Sub) IEC Best Practice Method is to load.cid file directly into IED Many vendors, however, use alternate vendor-specific method

61 IEC Defines Methods for Communications and Configurations

62 CID File in IED Provides Configuration Certainty, Settings Cannot be Verified SCD File CID File IED Configuration Tool SCD File ICD File Third Party IED IED Configuration Tool 3 rd Party IED UCA Style Settings SCD File SCD File Third Party IED IED Configuration Tool 3 rd Party IED UCA Style Settings

63 SEL Architect Works With Files From Any Vendor

64 Best Practice Provides Contextual Names Generic Names Less Useful Generic Specific Best practice provides specific names whenever possible Exceptions include generic logic points, unnamed contact I/O

65 SEL Architect Supports Best Practice GOOSE Interoperability with Any Vendor

66 Travel to Site Only After Notification via SCADA, , Text Message, Voic

67 IEC Specifies Time Synchronization One Order of Magnitude More Accurate Than Application Time Stamp Accuracy Requirment

68 Accurately Time Synchronize IED Clocks and Timestamp Measurements IEC has five time performance categories most severe requires +/- 1 µs Timestamp requires millisecond resolution Utilities replacing SNTP with IRIG for accuracy IEEE 1588 will be used in future SEL helping to develop this now Customers with systems say separate IRIG-B broadcast remains best solution today

69 Time Stamp Accuracy is +/- 1 millisec, Time Synch Accuracy is +/- 1 microsec IRIG-B via separate physical network, SEL agreed best practice, supports protection and archiving during failure of Ethernet LAN Simple Network Time Protocol (SNTP) or NTP can work over same LAN, but vary with traffic, fail with network accuracy between 1 to 50 msec

70 Synchronization Message Exchange Follow_Up message conveys the exact time when Sync message left the master. It can be omitted if the precise departure time can be inserted into the Sync message (by using special purpose hardware)

71 IEEE 1588 Requires Hardware Modification to Existing Products From All Manufacturers Deterministic access of the SNTP/NTP reply packets to the Ethernet wire at PHY (physical interface) level Time stamp of incoming and outgoing time packets to be performed at PHY level This prevents variable packet latency through the IED has no impact on the timing accuracy

72 IEC Guideform Specification (GFS) Details IED Capabilities Lessons learned and requirements detailed by numerous customers following numerous installations Details not mandatory for IEC conformance but necessary to satisfy projects

73 IEC GFS Examples Accept CID file directly into IED Be CERTAIN of changes, configuration Be CERTAIN that protection/logic is separate and not affected by communications changes Reduce testing, commissioning Multivendor IEC configuration tool

74 IEC GFS Examples Specific, rather than generic, data naming in logical nodes PRO.BS1XCBR1.stVal LD0.SPGGIO35.Ind.stVal 16 character IED name length Support existing end user naming methods Match SER, SCADA, HMI, archive, and settings naming

75 IEC GFS Examples Modify what data is available and naming within SCL file instead of firmware Modify naming to match customer requests Make customer/application specific templates Six concurrent client connections Dual primary HMI Dual primary Gateway Dual primary engineering access

76 IEC GFS Examples Eight or more GOOSE publications Unique VLAN for each message Configurable repetition time and priority 16 or more GOOSE subscriptions Message quality monitored and available for logic, alarming, reporting Data quality monitor on each value

77 IEC GFS Examples Provide Ethernet and GOOSE diagnostics within the IED Messaging statistics GOOSE message quality Telnet, FTP IED engineering access

78 IEC GFS Examples Support GPS time synchronization method accurate, available during network failure Support engineering access via Telnet and FTP Simple, universally well known methods Available on virtually every computer

79 IEC GFS Examples Support FTP, Telnet, SMART, MMS, GOOSE, IRIG, DNP IP, on one connection Support multiple Ethernet ports Directly in IED Rugged Ethernet manifold switch

80 IEC GFS Examples Documentation of interoperability Stage and test with other vendors Demonstrate bi-directional message exchange Demonstrate SCL customization via nonvendor specific configuration tool

81 IEC Standard Describes Switched Ethernet Station/Process Bus Ethernet Ethernet