Jay Britton jay.britton@areva-td.com CIM for UCTE Jay Britton jay.britton@areva-td.com

Issues Business Process (Use Cases) Format Compatibility 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.

UCTE Day-Ahead Congestion Forecast

UCTE Day-Ahead Congestion Forecast II

UCTE Day-Ahead Congestion Forecast III

The initial CIM model exchange standard focused on transfer of complete models: CIM Exchange (full, partial, incremental update) CIM import / export CIM import / export System B Import Model System A Import Model a Proprietary / Home grown Extract / Merge Tools Proprietary / Home grown Extract / Merge Tools b A Internal Model B’s Model of A System A Local Vendor Model System B Local Vendor Model A’s model of B B Internal Model System B EMS System A EMS

Basic 2-Region Process Example Site A makes a change: A changes its ModelAuthoritySet using its CIM modeller. A imports the change into its EMS. A exports the change to B. B receives the change (full or incremental), updating A’s ModelAuthoritySet within its CIM modeller. B renames any new elements and repeats any reduction of A’s ModelAuthoritySet. B imports the new model into its EMS.

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.

The CIM Model Exchange Business Process

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”.

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.

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

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.

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.