Copyright © SEL 2009Copyright © SEL 2009

Introduction and Overview of IEC 61850

Communications

Schweitzer Engineering Laboratories, Inc.

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 870 -

101/104, legacy, etc.

SEL Provides “Integration Best Practice”

& “Stand-Alone IED” Protocols

Global Ethernet tools - FTP, Telnet, Ping

Suite of IEC 61850 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

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

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

IEC 61850 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

Replace Field Wiring With

Ethernet LANs

Move data with same

methods from each

manufacturers’ devices

Group data logically

Create, find, and use

data with standardized

methods

Signal

List ……

……

……

……

……

……

……

……

……

……

……

……

……

……

……

……

LN

XCBR

LN

IHMI

LN

CSWI

Object List

Circuit Breaker

Station HMI

Switch Controller

Simplify

communications using

network methods

Communicate with

coexisting Ethernet

conversations

Apply familiar Internet

methods

Signal

List ……

……

……

……

……

……

……

……

……

……

……

……

……

……

……

……

LN

XCBR

LN

IHMI

LN

CSWI

Object List

Circuit Breaker

Station HMI

Switch Controller

Replace Field Wiring With

Ethernet LANs

Substation Configuration Language

(SCL) Provides Dictionary, Descriptions

SCL Includes Processes for Finding,

Describing, Classifying, Naming Data

SCL ClassificationStation: Oasis

Voltage level: 220 kV

Bay: Bay 1

Apparatus: Circuit breaker

Physical Device: SEL-421

Logical Device:* Meter (MET)

Logical Node (LN):* Measurements (MMXU)

LN Instance:* First measurement group (1)

Function:* Analog measurement (MX)

Data Object:* Frequency (HZ)

*Dictated by the standard Data name = MET.MMXU1.MX.HZ

SCL Taxonomy Used to Name IED Data

Within the Devices

Physical Device(SEL-421 IP Address)

Logical DeviceMET

(e.g. PRO, CON, ANN)

MMXU1 MMXU2

MXMX

HzA

Logical Nodes

Functional Constraints

“METMMXU2$MX$Hz” = Breaker #1 Frequency Measurements

Data Objects

Virtual View of Relay Data Map

Custom Prefixes Combined With Standardized

Naming Provide Intuitive Description

Physical DeviceLVD97010MCAD

(network address)

Logical DeviceLVD97010MCADCTRL1

XCBR1 XCBR1

PosPos

stVal

Logical Nodes

q

LVD97010MCAD.LVD97010MCADCTRL1.XCBR1.Pos.stVal

= Status value of position of circuit breaker #1

Data

ObjectData Attributes

Data names are explicit and aid browsing data within a SEL-421

IED Data Naming Within the Devices

Also Used “On the Wire” and In Clients

61850 Groups Data by Function,

Groups Called Logical Nodes

Each IED has Several Logical Devices,

Each With Multiple Logical Nodes

UDP/IPGSSE

T-Profile

Sampled

Values

(Multicast)

Generic

Object-

Oriented

Substation

EventTime Sync

(Method 2)

Core

ACSI

Services

Generic

Substation

Status Event

ISO/IEC 8802-3

ISO/IEC 8802-3 Ethertype

SV

(Type 4)

GOOSE

(Type 1, 1A)

GSSE

(Type 1, 1A)

GPS

IRIG-B

Time Sync

(Method 1)

Time Sync

(SNTP)(Type 6)

MMS Protocol

Suite (Type 2, 3, 5)

IEC 61850 – A Suite of Protocols;

Not Just One

IEC 61850 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*

5. Reporting of data from IEDs*

6. Unsolicited text messaging

7. Commanded or automatic

control of IED*

8. Peer-to-peer messaging

between IEDs*

9. Digitized instrument

transformer values*

10. Time synchronization*

11. Configuration revision

management

12. Engineering access

13. Alarm callout, dialback

14. Communications diagnostics

15. Local and wide area

synchrophasors

* Addressed by IEC 61850

Features and Attributes of IEC 61850

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

Routed and Nonrouted Protocols

Use Different Address Types

Nonrouted

Internet routed

Intranet multicast

David Dolezilek

2350 NE Hopkins Ct

Occupant

2350 NE Hopkins Ct

Each doorstep on the route

SMART, DNP3,

Modbus

MMS, FTP,

Telnet

GOOSE, SV

Nonrouted Messages are Authenticated

by Physical Address and Name

Internet WAN Routed Messages are

Delivered to Network Address

IEC 61850 MMS, Tunneled SEL Fast Messages, Tunneled SEL Mirrored Bits,

DNP3 IP, 870-104, Modbus TCP, other SCADA protocols

Internet WAN Routed Messages are

Delivered to Network Address

Intranet LAN Multicast Messages

Delivered to Everyone on the Intranet

IEC 61850 GOOSE, IEC 61850 SV

Goose and SV are Published to a Group

Address, Anyone Can Subscribe

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

Client Server Supports What You Want

When You Want

On

demand

or on data

change

Polling,

reporting,

ad-hoc

Like SMART, MMS Retrieves One Piece

of Information or Entire Report

Constant Repetition Serves Sampled

Data and GOOSE Integrity Heartbeat

Predictable receipt

Constant bandwidth

utilization

GOOSE Heartbeat

Messages, SV, Time

Synch

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

SVs Publish at Fixed Rate

Separate sampling

physically from Measurement

Metering

Calculation

Multiple subscribers

to each SV

IEC 61850-9-2 LE Sampled Values

Fixed Rate Publication Requirements

Sampling

Protection: 4, 4.8 kHz

Quality metering: 12.8, 15.36 kHz

Publication

Protection: 4, 4.8 kHz (one sample per message)

Quality metering

1.6, 1.92 kHz

(eight samples

per message)

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

MMS Client Server Applications Are Unaware

When Transport Layers Restore Lost Data

TCP Retransmission

and Reassembly

H

E

L

L

O

Data H Data E

Data L

Data L Data O HELO

Workstation Server

Retransmitted

H

E

L

L

O

Data LX

SEL Confidential

Like SEL MIRRORED BITS Before Them,

GOOSE and SV Replace Copper With Fiber

1

2

3

4

5

Data 1 Data 2 Data 3 Data 4 Data 5Lost Data With

Sequence #3

1

2

4

5

Workstation Server

GOOSE and SV Applications Survive

When Data Are Lost

No resend, next message already on its

way

To get this behavior, we have no

network layer, and therefore no WAN

routing

IEC 61850 GOOSE and SV Custom

Ethertypes Registered by IEEE

Ethertypes Determine the Network Layer

Connection

Use Ethertype Value

(hexadecimal)

IEC 61850-8-1 GOOSE 88-B8

IEC 61850-8-1 GSE Management 88-B9

IEC 61850-9-2 Sampled Values 88-BA

IEC 61850-8-1 MMS via IP 08-00 [Ethertype for all IP traffic]

1. Calculate New Hold Time

2. Start Hold Timer

3. Increment Sequence Number

Same GOOSE Message Sent Repetitively

as Hold Time Expires Until Data Change

Dataset Change

Retransmit-

Pending

Send Message

New State:

1. Set Sequence Number = 0

2. Increment State Number

3. Reset Hold Timer = Maximum Delay Time

Hold Timer Expired

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

Dataset Change Due to Discrete

Inputs and Logic Changing State

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

Transfer Time Includes Time to Detect,

Transfer, and Process Change

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

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

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

Priority Queuing and VLAN

Segregation Organize Ethernet Traffic

IEEE 802.1p priority

IEEE 802.1q segregation

Destination Address Data

TPID = 0 x 8100

Source Address Tag Type

x 0

16-bit type identifier

(constant)

0 x XXXx x

3-bit priority field12-bit VLAN

identifier

Physical Devices (PDs) Contain LN Data

Which Must be Exchanged Via Ethernet

PD1 Station Computer

PD2 Sync Relay

PD3 Bay Control

PD4 Distance,OC Relay

LN8

LN9

LN2

LN6

LN3

LN7

PD3PD2

PD1

LN4

LN1

LN5

PD4

Applications Require Logical

Association Between Logical Nodes

LN8

LN9

LN2

LN6

LN3

LN7

PD3PD2

PD1

LN4

LN1

LN5

PD4

Logical Nodes Combine to Create Functions

Functions

Synchronized

CB SwitchingLogical

Nodes

HMI

(IHMI)

Breaker

(XCBR)

Distance

Protection

(PDIS)

Overcurrent

Protection

(PTOC)

Distance

Protection

Overcurrent

Protection

LN1 LN2 LN3

LN4

LN5

PD1

PD2

PD3

PD4

Synch Check

(RSYN) Physic

al D

evic

es

LN6 LN7

LN8

LN9

F1 F2 F3

Functions (F) Often Logically Connect

Several Physical Devices

LN8

LN9

F2

F3

LN2

LN6

LN3

LN7

PD3PD2

PD1

F1

LN4

LN1

LN5

PD4

Additional Physical Device, Same FunctionsFunctions

Synchronized

CB SwitchingLogical

Nodes

HMI

(IHMI)

Breaker

(XCBR)

Distance

Protection

(PDIS)

Overcurrent

Protection

(PTOC)

Distance

Protection

Overcurrent

Protection

LN1 LN2 LN3

LN4

LN5

PD1

PD2

PD3

PD4

PD5

Synch Check

(RSYN) Physic

al D

evic

es

LN6 LN7

LN8

LN9

F1 F2 F3

Same Functions, Different Logical

Node Allocation

PD4

LN8

LN9

F2

F3

LN2

LN6

LN3

LN7

PD3PD2

PD5PD1

F1

LN4

LN1

LN5 PD1 Station Computer

PD2 Sync Relay

PD3 Bay Control

PD4 Distance Relay

PD5 OC Relay

Data are Segregated Based on

Functions Via VLAN Tags on Messages

F1 VLAN 1, PD1, PD2, PD3

F2 VLAN 2, PD1, PD3, PD4

F3 VLAN 3, PD1, PD3, PD5

PD4

LN8

LN9

F2

F3

LN2

LN6

LN3

LN7

PD3PD2

PD5PD1

F1

LN4

LN1

LN5

Devices listen to only the messages necessary to participate in a function

Biggest Difference Between UCA and

IEC 61850 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

System Specification Description

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

System Specification Tool

SSDFile

Library

SSD: One-Line and Functions

PTOCTCTR

MMXU

XCBR

XSWI

CSWI

CSWI

CILO

YLTC ATCC

PTOCTCTR

MMXU

XCBR

XSWI

CSWI

CSWI

CILO

YLTC ATCC

IHMI ITCI

Bay

=Q1

Bay

=Q2

Station

Computer

NCC

Gateway

PTOCTCTR

MMXU

XCBR

XSWI

CSWI

CSWI

CILO

YLTC ATCC

PTOCTCTR

MMXU

XCBR

XSWI

CSWI

CSWI

CILO

YLTC ATCC

IHMI ITCI

Bay

=Q1

Bay

=Q2

Station

Computer

NCC

Gateway

IED Capability Description

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

Control blocks – not populated

Think of it as an “Default IED template”

IED Configuration Tool

ICD

File

Library

ICD: Map IEDs to Logical Devices

PTOCTCTR

MMXU

XCBR

XSWI

CSWI

CSWI

CILO

YLTC ATCC

PTOCTCTR

MMXU

XCBR

XSWI

CSWI

CSWI

CILO

YLTC ATCC

IHMIStation

Computer

NCC

Gateway

ControllerController

Protection Protection

Tap changer Controller Tap ch . Contr.

Switch IED

Breaker IED

MU

Transformer IED

Switch Switch

Switch Switch

Switch

IHMI

Bay Bay

PTOCTCTR

MMXU

XCBR

XSWI

CSWI

CSWI

CILO

YLTC ATCC

PTOCTCTR

MMXU

XCBR

XSWI

CSWI

CSWI

CILO

YLTC ATCC

IHMIIHMIStation

Computer

NCC

Gateway

ControllerController

Protection Protection

Tap changer Controller Tap ch . Contr.

Switch IED

Breaker IED

MU

Transformer IED

Switch Switch

Switch Switch

Switch

IHMIIHMI

Bay Bay

ICD

File

ICD

File

ICD

File

System Configuration Description

The substation configuration description file (.scd) describes the complete substation configuration

Single-line diagram

Communication network

IED configurations

Binding information (e.g., trip matrix)

ICD

File

SCD

File

System Configuration Tool

SSD

File

SCD: Add the Communications

Controller

PTOC

Protection 1

MMXU

CSWI

CSWI

CILO

ATCC

PTOC

Protection 2

Switch

Switch

Switch

Bay

Process level

bus segments

Station level

and interbay

Bus, e.g. ring

XCBR

XSWI

YLTC

Switch IED

Breaker IED

MU

Transformer IED

TCTR

TvTR

TCTR

TVTR

XCBR

Controller

PTOC

Protection 1

MMXU

CSWI

CSWI

CILO

ATCC

MMXU

CSWI

CSWI

CILO

ATCC

PTOC

Protection 2

Switch

Switch

Switch

Bay

Process level

bus segments

Station level

and interbay

Bus, e.g., ring

XCBR

XSWI

YLTC

Switch IED

Breaker IED

MU

Transformer IED

TCTR

TvTR

TCTR

TVTR

XCBR

Configured IED Description

The configured IED description file (.cid) describes customized

configuration parameters for specific IED (Feeder #1, Oasis Sub)

IEC 61850 “Best Practice Method” is to load .cid file directly into

IED

Many vendors, however, use alternate vendor-specific method

CID File

IED Configuration Tool

SCD

FileOr

ICD

File

IEC 61850 Defines Methods for

Communications and Configurations

CID File in IED Provides Configuration

“Certainty”, Settings Cannot be VerifiedCID File

IED Configuration Tool

SCDFile

ICDFile

IED Configuration Tool

SCDFile

3rd Party IED

UCA Style Settings

Third Party

IED

SCD File

IED Configuration Tool

SCDFile

3rd Party IED

UCA Style Settings

Third Party

IED

SEL Architect Works With Files From

Any Vendor

“Best Practice” Provides Contextual

Names – Generic Names Less Useful

Best practice provides specific names whenever possible

Exceptions include generic logic points, unnamed contact I/O

Generic Specific

SEL Architect Supports “Best Practice”

GOOSE Interoperability with Any Vendor

Travel to Site Only After Notification via

SCADA, email, Text Message, Voicemail

IEC 61850-8 Specifies Time Synchronization

One Order of Magnitude More Accurate Than

Application Time Stamp Accuracy Requirment

Accurately Time Synchronize IED Clocks

and Timestamp Measurements

IEC 61850 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

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

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)

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

Lessons learned and requirements

detailed by numerous customers following

numerous installations

Details not mandatory for IEC 61850

conformance but necessary to satisfy

projects

IEC 61850 Guideform Specification

(GFS) Details IED Capabilities

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 61850 configuration tool

IEC 61850 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

IEC 61850 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

IEC 61850 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

IEC 61850 GFS Examples

Provide Ethernet and GOOSE diagnostics

within the IED

Messaging statistics

GOOSE message quality

Telnet, FTP IED engineering access

IEC 61850 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

IEC 61850 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

IEC 61850 GFS Examples

Documentation of interoperability

Stage and test with other vendors

Demonstrate bi-directional message

exchange

Demonstrate SCL customization via non-

vendor specific configuration tool

IEC 61850 GFS Examples

Ethernet

Ethernet

IEC 61850 Standard Describes Switched

Ethernet Station/Process Bus