1. Communication Networks and Systems In Substations
IEC Primer -
Communication Networks and Systems In Substations
February 16, 2005

2. 61850 Scope

3. Abstract Communications Service Interface ACSI
Defines a set of Objects
Defines a set of Services to manipulate and access those objects
Defines a base set of data types for describing objects

4. Functional Constraint
Anatomy of an IEC61850 Object Name
MMXU1 MX V
MMXU2 MX A
Logical Device
(e.g. Relay1)
Physical Device
(network address)
Functional Constraint
Logical Nodes
“MMXU2$MX$A” =
Feeder #2 Current Measurements

5. Logical node groups M Metering and measurement (8)
S Sensor and monitoring (4)
X Switchgear (2)
T Instrument transformers (2)
Y Power transformers (4)
Z Further power system equipment (15)
L System LN (2)
P Protection (28)
R Protection related (10)
C Control (5)
G Generic (3)
I Interfacing and archiving (4)
A Automatic control (4)
Examples:
PDIF: Differential protection
RBRF: Breaker failure
XCBR: Circuit breaker
CSWI: Switch controller
MMXU: Measurement unit
YPTR: Power transformer

6. Services Examples GetData – Read SetDataValues – Write
GetDataDirectory – Read list of object names

7. ACSI Services
Enable
Self
Describing
Devices

8. IEC61850 Profiles

9. IEC61850 Documents Mapping to MMS and Ethernet Basic principles Part 1
Glossary
Part 2
General Requirements
Part 3
System and project management
Part 4
Communication requirements
Part 5
Substation Automation System Configuration
Part 6
Basic Communication Structure
Part 7
Mapping to MMS and Ethernet
Sampled Measured Values
Part 8
Part 9
Mapping to Ethernet
Conformance testing
Part 10

10. IEC61850 – Primary Parts
Part 6-1: Substation Configuration Language (SCL)
Part 7-2: Abstract Communications Service Interface (ACSI) and base types
Part 7-3: Common Data Classes (CDC)
Part 7-4: Logical Nodes
Part 8-1: Specific Communications Service Mappings (SCSM) - MMS & Ethernet
Part 9-2: SCSM - Sampled Values over Ethernet
Part 10-1: Conformance Testing

11. IEC61850 Substation Architecture
MU = Merging Unit MU
PT1
Optical CT
PT2
CT2 PT
Relay
MU Publishes
V/I/Status
Datasets
Relay(s)
Subscribe to
I/O
Station Bus -
10/100/1000 MB Ethernet
Process Bus
.1/1/10GB
Ethernet
Clk1
Clk2
Remote
Access
Network
IED

12. Sampled Measured Values

13. Peer to Peer Communications Functional Requirements
Relay
Relay
Relay
Relay
. . .
Bkr 1
Bkr 2
Bkr 3
Bkr N
Trip
BFI
Message delivery to multiple devices simultaneously
Fast Delivery (< 4ms)

14. IEC61850 Generic Object Oriented Substation Event - GOOSE
Device to multi-device communication – Local or Wide Area
Bridgeable but Non-routable
User-defined Dataset sent in an Ethernet Multicast message
Message sent on change of state as well periodically to enable detection of device failure
Reliability effected through message repeat
GOOSE Header:
Multicast Address
Name
Time Until Next GOOSE
Etc.
User-Defined Dataset
Status Information
Analog Values
Data Quality
Time

15. SCL – Substation Configuration Language
Description language for communication in electrical substations related to the IEDs
XML based language that allows a formal description of
Substation automation system and the switchyard and the relation between them
IED configuration

16. SCL File Types
SSD: System Specification Description. XML description of the entire system.
SCD: Substation Configuration Description. XML description of a single substation.
ICD: IED Capability Description. XML description of items supported by an IED.
CID: Configured IED Description. XML configuration for a specific IED.

17. Benefits of IEC61850
High-level services enable self-describing devices & automatic object discovery saving $$$$$ in configuration, setup and maintenance.
Standardized naming conventions with power system context eliminates device dependencies and tag mapping saving $$$$ in config., setup, and maint.
Standardized configuration file formats enables exchange of device configuration saving $$$$ in design, specification, config., setup, and maint.

18. Benefits of IEC
Higher performance multi-cast messaging for inter-relay communications enables functions not possible with hard wires and save $$$$ in wiring and maintenance.
Multi-cast messaging enables sharing of transducer (CT/PT) signals saving $$$$ by reducing wiring and connection costs