Implementing a substation
abstraction model
Outside of - but ready for - IEC 61850
Initial project description
• Replace mechanical switch/indicator panels
with computer based HMI.
• Optimize use of protection IEDs.
• Supply some I/O for general purposes.
• Remote link to SCADA was still through RTU,
so out of scope.
• SaskPower is looking for a general solution
Project requirements as clarified
during kickoff meeting
• Standard SaskPower naming should be followed.
– HMI standards from SCADA to be followed.
• Different protection schemes used by SaskPower:
• A-B protection.
• Single protection IED.
• Motorized switches wired to IED.
• General I/O wired to separate I/O units.
• Work order tags should imitate existing paper cards.
Protection IEDs
• For each breaker there is one or two
protection IEDs in an A-B scheme depending
on the breaker function.
• Protection IEDs use DNP3 for communications
but SaskPower is considering IEC 61850 IEDs:
system must be protocol agnostic.
• Local HMI operator Open & Close operations
are performed through IEDs.
Abstraction model idea
Need to organize the information:
• Switchyard-oriented (breaker, switches, lines).
• Independent of used IEDs.
• Standard data list for objects.
• Combine data:
– from multiple IEDs;
– from additional I/O modules.
Abstraction model requirements
• Standard number of data points for each
object.
• Standard naming enforcement.
• Flexible logic processing:
– Data from multiple IEDs to be combined.
– Data from additional I/O modules to be included.
Abstraction model advantages
• Better separation between apparatus data, used protocols,
and physical IEDs.
• Logical architecture is completely IED-independent.
• Supports all types of schemes (A-B protection,
single IED, hard I/O only).
• Includes all needed additional logic.
• Possible to add non-telemetered objects.
• Easier to enforce utility naming conventions.
• Standard data for HMI software, easier to make standard HMI
library objects.
Abstraction model
• Main interface to
local HMI.
• Combines data
from any source.
• Includes all
needed logic.
Abstraction model details
• Standard Names.
• Combination of data.
• Additional logic is
possible.
Abstraction model details
• Objects are defined as general as possible:
– Breaker will cover oil/SF6 breakers.
– Switches will cover single/dual/center break switches.
• Manual switches are also included.
• Naming:
– Logical model is following SaskPower standards like Red/Yellow/Blue
for the phases.
– IED naming is following IED documentation like A/B/C.
• Additional logic used:
– Enable option for alarms.
– Scaling and other calculations.
Yellowhead:
logical Single Line Diagram
Identification of all
logical objects in
station.
Yellowhead: Abstaction model
• 29 Logical objects including the general station.
• 12 physical IEDs and I/0 modules.
Link between IED
data and logical
model determinated
by SaskPower and
CPS engineers
HMI visualization and control
• There are 2 levels of visualization and control:
– Remote SCADA, through RTU
(out of scope in first station).
– Local substation HMI.
• Selection between control authority is done
through selectors
– Substation Remote/Local.
Main SLD
Navigation
options
Local/Remote
selector
HMI library
objects
Breaker object
Alarm
indications
Alarm enable
options
Tagging
Conclusion/Lessons learned
• Importance of model base definition:
– Combination of SaskPower and Cooper Power System engineers’
knowledge gives the best of both worlds.
– Need good interaction between protection and communication
engineers to map the IED data to the logical model.
• With the data models, configuration is straight forward.
• Creation of HMI is straight forward with the library objects.
• For second station, only small adjustments were needed.
Next steps
• Implement next station using IEC 61850
communication with IEDs.
• Map the logical models into a standard DNP3
interface for SCADA thus replacing the RTU.
• Map the logical models into an IEC 61850
interface, if needed.
Contact information
Gerrit Dogger
Senior Product and Application Specialist
Cooper Power Systems
gerrit.dogger@cooperindustries.com
Jack Clarkson
Project Leader, Engineering
SaskPower
jclarkson@saskpower.com
Nicholas Dietrick
Engineer-In-Training, Substations
SaskPower
ndietrick@saskpower.com
Philip Tempel
Senior Substations Design Engineer
SaskPower
ptempel@saskpower.com
Sukhbir Sachdev
Senior Substations Design Engineer
SaskPower
ssachdev@saskpower.com