3 3
Issues
Business Process (Use Cases)
How does the UCTE DACF compare with CIM model exchange processes?
Format Compatibility
UCTE DEF is a power flow format.
CIM/XML (452/552) is an EMS model exchange format.
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UCTE Day-Ahead Congestion Forecast
UCTE Server
UCTE DEF UCTE DEF
Study tools / Site BStudy tools / Site A
My TSO Model My TSO Model
My External Model
My UCTE Model My UCTE Model
a b
Neighbor TSOs
Extract / reduce
Merge
My External Model
Neighbor TSOs
Extract / reduce
Merge
Day Ahead Power Flow /
CA
Day Ahead Power Flow /
CA
Extract
My Internal Model
My Internal Model
Extract
Neighbor TSOs Neighbor TSOs
DEF Translator A
TSO “B”TSO “A”
DEF Translator B
X nodes
X nodes
X nodes
Internal model upload to UCTE Server
External model download to TSO
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UCTE Day-Ahead Congestion ForecastII
UCTE Server
DEF DEF
Study tools / Site BStudy tools / Site A
TSO Model TSO Model
My External Model
My UCTE Model My UCTE Model
a b
Full Interconnection Model
Extract / reduce
Merge
My External Model
Full Interconnection Model
Extract / reduce
Merge
UCTE Study tools
Full Interconnection Input Model
Merge
Full Interconnection Power Flow
Full Interconnection Output Model
Day Ahead Power Flow /
CA
Day Ahead Power Flow /
CA
Extract
My Internal Model
My Internal Model
Extract
Full Interconnection Output Model
Full Interconnection Output Model
DEF Translator A
TSO “B”TSO “A”
DEF Translator B
DEF Translator B
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UCTE Day-Ahead Congestion ForecastIII
DEF
DEF DEF
EMS format / Site BEMS format / Site A
A Region Model B Region Model
My External Model
EMS Operations Model EMS Operations Model
a b
Full Interconnection Model
Extract / reduce
Merge
My External Model
Full Interconnection Model
Extract / reduce
Merge
UCTE
Full Interconnection Input Model
Merge
Full Interconnection Power Flow
Full Interconnection Output Model
Day Ahead Power Flow /
CA
Day Ahead Power Flow /
CAExtract
My Internal Model
My Internal Model
Extract
Full Interconnection Output Model
Full Interconnection Output Model
DEF Translator A
B Region ModelA Region Model
DEF Translator B
DEF Translator B
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CIM Exchange(full, partial, incremental update)
The initial CIM model exchange standard focused on transfer of complete models:
A Internal Model
A’s model of B
baProprietary / Home grown
Extract / Merge Tools
Proprietary / Home grown
Extract / Merge Tools
CIM import / export
System A Local Vendor
Model
System A Import Model
B’s Model of A
B Internal Model
System B Local Vendor
Model
System B Import Model
CIM import / export
System A EMS System B EMS
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Basic 2-Region Process Example
CIM ModelerFullInterconnectionModel
CIM ModelerFullInterconnectionModel
EMS at Site BEMS at Site A
System A Source
System B Import
boundary
System B Source
System A Import
boundary
My A Region(reduced & renamed)
My B Region(reduced & renamed)
CIM Translator A
EMS AProprietary Model Format
CIM Translator B
EMS BProprietary Model Format
CIM/XMLModel Exchange
Interface
a b
Site A makes a change:
1. A changes its ModelAuthoritySet using its CIM modeller.
2. A imports the change into its EMS.
3. A exports the change to B.
4. B receives the change (full or incremental), updating A’s ModelAuthoritySet within its CIM modeller.
5. B renames any new elements and repeats any reduction of A’s ModelAuthoritySet.
6. B imports the new model into its EMS.
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Hierarchical Process Definition for an Interconnection
Bottom level.
No significant differences.
Export changes as the model authority.
Import externals from the full interconnection model.
Upper level:
Manages boundary sets.
Creates the full interconnection model.
Model quality evaluation.
Study state estimation.
Derives operational model in the same manner as lower levels.
Different reduction criteria.
Design extends to any number of hierarchical levels.
CIM Modeler
CIM ModelerFullInterconnectionModel
CIM ModelerFullInterconnectionModel
EMS at Site BEMS at Site A
System A Source
System B Import
boundary
System B Source
System A Import
boundary
My A Region(reduced & renamed)
My B Region(reduced & renamed)
CIM Translator A
EMS AProprietary Model Format
CIM Translator B
EMS BProprietary Model Format
a b
FullInterconnectionModel
System A Import
System B Import
boundary x
Upper Level Reliability Model
EMS at Upper Level Authority
CIM Translator
EMS Upper LevelProprietary Model Format
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The CIM Model Exchange Business Process
PRIMARY Interconnection
Model
Derived Model
TSO 1 External Model
Assembly of full primary model
Creation of derived target models
Model Authority 1 EMS
Model Authority 2 EMS
Model Authority n EMS
Interconnection EMS
TSO 1 Internal Model
TSO 2External Model
TSO 2 Internal Model
TSO n External Model
TSO n Internal Model
Interconnection Planning
Derived Model
TSO 1 Plans
TSO 2 Plans
TSO n Plans
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Format Issue: Bus-Branch Models
UCTE (and other power flow formats) are “bus-branch”
Substations have one “bus” for each normally connected set of bus sections.
Switches and circuit breakers are normally not modeled.
Bus numbers or names are often the key tool for engineers in navigating the model and comparing results.
CIM EMS modeling is “node-breaker”
Substation switches and breakers are normally modeled so that real-time configurations can be evaluated.
Nodes represent bus sections and other electrical junctions.
Buses are calculated as a result of “topology processing”.
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Format Issue: Bus-Branch Models
Problem has been discussed extensively in the 2007 “CIM for Planning”.
Solution:
Models that only require bus-branch detail simply use one CIM ConnectivityNode per Bus.
When a CIM model is converted to bus-branch form,
The output of the topology processor is used to form buses.
Markers may be added to the CIM modelling to allow consistent buses to be named consistently.
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Format Issue: Dynamic Data
UCTE and CIM are not “information equivalent”
UCTE (and other power flow formats) represent one point in time
Load and generation at a bus
Desired voltage
Cap bank input
CIM EMS models describe network parameters over time.
Time Schedules
Load Distribution Patterns
Generation and Interchange
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Converting CIM Dynamic Data to UCTE
EMS products have been converting EMS formats to various power flow formats, including EMS, for some time.
Solution:
Scheduling functions calculate values at time T.
Same procedures are used as occurs within an EMS to set up a power flow.
Power flow formats are produced from power flow scheduling functions, not from the raw modeling data.
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Converting UCTE Dynamic Data to CIM
Has been done when power flow cases are used to create external models for EMS.
Solution One – No Changes to CIM: Power flow values for load, desired voltage, etc. are used to
reverse engineer dummy schedules.
Load distribution works pretty well, but other schedules are not usually very good and need amendment.
This approach is most appropriate as a partial initialization procedure for externals.
Solution Two – CIM extensions required: Single time point, power flow input variables are added to the CIM
model.
A new CIM “Scheduled Output Interface” is defined between scheduling and network analysis.
UCTE data uses the new interface rather than the 452 model exchange interface.
This is probably the more appropriate solution for most real business situations.