Using IED Data To Implement Substation Automation Functions Reducing Costs by Reusing Available Data Gerrit Dogger Product and Application Specialist Cybectec Inc.
Using IED Data To ImplementSubstation Automation Functions
Reducing Costs by Reusing Available Data
Gerrit DoggerProduct and Application Specialist
Cybectec Inc.
2
Objectives
Where are we and what is neededThe benefits of using IED dataDiscussion of challenges and their solutionsDiscussion of future developmentsReal-world case study: Emergency power management and load restoration
3
Substation Evolution1/2Existing situation
SCADA
RTU
IED
PROTECTION METERING POWERQUALITY
4
Substation Evolution2/2New situation:
IEDs for protection, measurement and controlSubstation gateway/data concentrator for communication
IED
PROTECTION METERING POWERQUALITY
5
Automation Requirements
Substation automation functions need –Access to all substation dataControl capability of substation switchgearA device with programming capability
6
Introducing the Intelligent GatewayA communications gateway provides data access and control capabilitiesAn intelligent gateway also provides automation capabilities
Replaced by
7
Direct Benefits of the Intelligent Gateway
No PLC or other additional devices neededFewer devices reduce administrative costsNo additional cabling – IEDs are already connectedOpportunity for optimized price/performance relay configuration
Reinforced by the additional intelligenceSimplified substation architecture – vendor independent
8
Indirect Benefits of the Intelligent GatewayThese might be more important in the long run –
Simpler diagrams because of reduced cablingLess maintenance on diagramsFewer devices means
Fewer spare partsLess training
9
Challenges and Their Solutions
Using intelligent gateways introduces new challenges –Response timesException handlingSupporting redundancy
10
Response Times – Issues
Data acquisition delays due to communication between gateway and IEDDelay in command execution
Note: Immediate faults are handled by the IED.
11
Response Times – Solutions
Modern protocols reduce data acquisition delays –DNP3, IEC 60870-5-101, IEC 60870-5-104 use unsolicited reporting
12
Response Times – Solutions
Processor/task priority reduce the command delay –High priority for
Automation tasksCommand handlingIED command handling
13
Exception Handling – Issues
Special care needs to be taken for –Invalid incoming dataCommand execution error handling
14
Exception Handling – Solutions
Data invalidity can be handled by –Checking individual data point quality Checking the communication link status
15
Exception Handling – Solutions
For command execution –Check the protocol command acknowledgementCheck the corresponding indications
16
Supporting Redundancy – Issues
Redundancy introduces additional challenges –Correct handling of failover situationsSynchronization of data between the programsNo or limited concurrent execution
17
Supporting Redundancy – Solutions
To ensure correct execution –Plan redundancy from the startUse internal program indicationsUse external indications – binary inputs
18
Supporting Redundancy – Solutions
Fast failover needs data synchronizationGateway must address this issue
19
Supporting Redundancy – Solutions
Both synchronized gateways might execute the program.Highly undesirable Should be solved in the design
20
Future Developments
Some trends we see developing:IEC 61850 – GOOSE messages can optimize interaction
Communication availability Substations can share more dataThis enables region-wide automation
21
Real-World Case Study: Emergency Power Management and Load Restoration
EDG #3 EDG #2 EDG #1
Incomer #1 Incomer #2
52L-3
52L-2 52L-1 52R-1
52R-2
52L-RNO
F17F16F1 F2
22
REDUNDANT CONTROLCENTERS
REDUNDANT GATEWAYS
EDG MCP
INCOMERUNDERVOLTAGE
PLCS
FEEDER IEDSGENERATORBREAKER IEDS
23
Start state
Wait for feeders toopen
IDLE
C: Start of SMPA: Initialize system
C: NOT `Permissive to syn and close EDG`s CBs`
A: Open feeders
Wait for powerfrom generators
C: (Both incomers open &
A: Set `Permissive to syn and close EDG`s CBs
C: All feeders open &C: Bus load less than 1 MW) OR
Closing feeders
C: 1 or more EDG`s CB s closedA: Calculate power
C: Power is availableA: Calculate power
C: One or both incomers closed
Wait for closeconfirmation
C: (Feeder is closed || timeout (5sec)) &
A: Determine next feederC: Not all feeder are closed
A: Determine next feeder
A: Close selected feeder
C: Both incomers open &
C: `Permissive to syn and close EDG`s CBs`C: Both incomers open &
C: `Permissive to syn and close EDG`s CBs`C: One or both incomers closed &
A: Reset `Permissive to syn and close EDG`s CBs
C: FeederOpenTimer timout (10 sec)
C: One or both incomers closed
C: One or both incomers closed
Determine CloseFail
C: All feeders Done &
A: Retrycounter := Retrycounter + 1C: Retrycounter < 3
C: Feeders to retry deteminatedA: Determine next feeder
C: One or both incomers closed
Initialization andIDLE state
Blackout: open feeders
Feeders open:Start generators
Power:Close feeders
(priority based)
Retry feeders that didn’t close
24
Emergency Power Management and Load Restoration
Basic factsPut into service in November 2005Normal conditions: restore power within 1 minute
Mainly waiting for generators to come onlineFailover condition: restore power within 1.5 minutes
25
Concluding Remarks
BenefitsNo additional hardwareUses existing data and wiringFewer spare partsLower administration costs –
Minimal training neededEverything is available to implement it nowProven concept
26
Concluding Remarks
DevelopmentBetter interaction using IEC 61850 GOOSE messagesUpcoming opportunities for region-wide automation
28
Questions?