Using IED Data To Implement
Substation Automation Functions
Reducing Costs by Reusing Available Data
Gerrit Dogger
Product and Application Specialist
Cybectec Inc.
Objectives
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Where are we and what is needed
The benefits of using IED data
Discussion of challenges and their solutions
Discussion of future developments
Real-world case study:
Emergency power management and load restoration
Substation Evolution
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SCADA
Existing situation
IED
RTU
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PROTECTION
METERING POWER
QUALITY
Substation Evolution
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New situation:
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IEDs for protection,
measurement and control
Substation gateway/data
concentrator for
communication
IED
PROTECTION
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METERING POWER
QUALITY
Automation Requirements
Substation automation functions need –
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Access to all substation data
Control capability of substation switchgear
A device with programming capability
Introducing the Intelligent Gateway
A communications gateway provides data access
and control capabilities
An intelligent gateway also provides automation
capabilities
Replaced by
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Direct Benefits of the Intelligent
Gateway
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No PLC or other additional devices needed
Fewer devices reduce administrative costs
No additional cabling – IEDs are already connected
Opportunity for optimized price/performance relay
configuration
‹ Reinforced by the additional intelligence
Simplified substation architecture – vendor independent
Indirect Benefits of the Intelligent
Gateway
These might be more important in the long run –
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Simpler diagrams because of reduced cabling
Less maintenance on diagrams
Fewer devices means
‹ Fewer spare parts
‹ Less training
Challenges and Their Solutions
Using intelligent gateways introduces new challenges –
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Response times
Exception handling
Supporting redundancy
Response Times – Issues
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Data acquisition delays due to communication between
gateway and IED
Delay in command execution
Note: Immediate faults are handled by the IED.
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Response Times – Solutions
Modern protocols reduce data acquisition delays –
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DNP3, IEC 60870-5-101, IEC 60870-5-104 use unsolicited
reporting
Response Times – Solutions
Processor/task priority reduce the command delay –
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High priority for
‹ Automation tasks
‹ Command handling
‹ IED command handling
Exception Handling – Issues
Special care needs to be taken for –
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Invalid incoming data
Command execution error handling
Exception Handling – Solutions
Data invalidity can be handled by –
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Checking individual data point quality
Checking the communication link status
Exception Handling – Solutions
For command execution –
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Check the protocol command acknowledgement
Check the corresponding indications
Supporting Redundancy – Issues
Redundancy introduces additional challenges –
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Correct handling of failover situations
Synchronization of data between the programs
No or limited concurrent execution
Supporting Redundancy – Solutions
To ensure correct execution –
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Plan redundancy from the start
Use internal program indications
Use external indications – binary inputs
Supporting Redundancy – Solutions
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Fast failover needs data synchronization
Gateway must address this issue
Supporting Redundancy – Solutions
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Both synchronized gateways might execute the program.
‹ Highly undesirable
‹ Should be solved in the design
Future Developments
Some trends we see developing:
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IEC 61850 – GOOSE messages can optimize interaction
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Communication availability
‹ Substations can share more data
‹ This enables region-wide automation
Real-World Case Study: Emergency
Power Management and Load Restoration
Incomer #1
Incomer #2
EDG #1
EDG #2
EDG #3
52R-2
52L-3
52L-2
52L-1
52R-1
52L-R
NO
F1
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F2
F16
F17
REDUNDANT CONTROL
CENTERS
REDUNDANT GATEWAYS
EDG
MCP
INCOMER
UNDERVOLTAGE
PLCS
GENERATOR
BREAKER IEDS
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FEEDER IEDS
Start state
Initialization and
C: Start of SMP
A: Initialize system
IDLE state
C: One or both incomers closed &
C: `Permissive to syn and close EDG`s CBs`
A: Reset `Permissive to syn and close EDG`s CBs
IDLE
C: Both incomers open &
C: NOT `Permissive to syn and close EDG`s CBs`
A: Open feeders
C: Both incomers open &
C: `Permissive to syn and close EDG`s CBs`
Wait for feeders to
open
C: One or both incomers closed
Blackout:
open feeders
C: (Both incomers open &
C: All feeders open &
C: Bus load less than 1 MW) OR
C: FeederOpenTimer timout (10 sec)
A: Set `Permissive to syn and close EDG`s CBs
Wait for power
from generators
C: One or both incomers closed
Feeders open:
Start generators
C: 1 or more EDG`s CB s closed
A: Calculate power
A: Determine next feeder
C: All feeders Done &
C: Retrycounter < 3
A: Retrycounter := Retrycounter + 1
Retry feeders that
didn’t close
C: One or both incomers closed
Closing feeders
C: Power is available
A: Calculate power
A: Close selected feeder
Determine Close
Fail
Wait for close
confirmation
C: Feeders to retry deteminated
A: Determine next feeder
C: One or both incomers closed
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C: (Feeder is closed || timeout (5sec)) &
C: Not all feeder are closed
A: Determine next feeder
Power:
Close feeders
(priority based)
Emergency Power Management and Load
Restoration
Basic facts
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Put into service in November 2005
Normal conditions: restore power within 1 minute
‹ Mainly waiting for generators to come online
Failover condition: restore power within 1.5 minutes
Concluding Remarks
Benefits
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No additional hardware
Uses existing data and wiring
Fewer spare parts
Lower administration costs –
‹ Minimal training needed
Everything is available to implement it now
Proven concept
Concluding Remarks
Development
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Better interaction using IEC 61850 GOOSE messages
Upcoming opportunities for region-wide automation
Contact Information
Gerrit Dogger
Product and Application Specialist
Cybectec Inc.
Gerrit.Dogger@Cybectec.com
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Questions?
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