A TSO perspective on CIM

Statnett Presentation

CIM User Group Meeting in London, May 16th 2012

Agenda for the presentation

Norwegian power system characteristics

Why is Statnett moving to CIM

Our work processes to get there

Challenges

Experiences and pitfalls

Norwegian power system key data:

Peak load – 24 000 MW Lowest load – 8 000 MW Production capacity:

26-27 000 MW 96-97 % hydro power Only 80 plants > 100 MW 800+ plants < 10 MW

Connections to: Russia (AC-line) Finland (AC-line) Sweden (AC-lines) Denmark (HVDC links) Netherlands (HVDC link)

What & who?

Statnett is the Norwegian TSO

Owns 90-95 % of the main grid (400-300kV) Does not own any generation except two

emergency gas-fired plants

Regional utilities own most of the sub-transmission grid

Power system data coordinator for all grid components > 22 kV

Why moving to CIM

We don't move to CIM just for the fun of it.. Correct power system data is a cornerstone in

our company, like all other TSO's Today different tools in Statnett model the grid

individually and with different methodology EMS/Scada system (SPIDER Ventyx/ABB) Operational planning and training (Aristo) System development planning (PSS®E) Protection planning (PSS®E)

The PSS/E models have more or less the same basic data modelled but different modelling practice

Not efficient…

Motivation for moving to CIM

Identified internal benefits:

Improved data consistency and quality for operation, planning and protection

A common topology enables efficient exchange of model case data between different tools Today this exchange requires a lot of manual work

A common power system modelling practice within the company Shortage of Power Engineers requires efficient handling of model data A common CIM based model will promote a common terminology A common model maintenance strategy

Identified external benefits:

Necessary to fulfil required standards for exchange of planning models within ENTSO-E

Make it possible for regional utilities to use different analysis software than Statnett

Work process for the CIM move

Initially we tested the model merging process on a small part of the national grid (approx. 10 % of the grid)

This pilot project showed that the CIM move was achievable, but also that.. Improvements in the CIM software tool (PSS®ODMS)

were necessary to support our work The CIM standard itself didn't fully cover our needs The mapping and merging of data from the different

models to a common model would require a lot of effort

Work process for the CIM move

Statnett defined a strategy with several directions

Cooperation with vendor (Siemens PTI) in development of software improvements

Influence the CIM standard to include our needs for information and structure in the model

Starting to change our internal work processes to make them "CIM compliant"

Challenges

Existing internal models differed, both in accuracy and level of detail Time consuming to define which model had the

best data for different data types, and the most complete/detailed model

The EMS system was clearly most detailed, but lacked significant data for protection and planning

Data must be modelled CIM compliant, but CIM isn't necessarily model compliant..

Challenges

CIM is still young with respect to modelling capability and documentation Seen from the perspective of a planning and protection

engineer, a pure CIM based model is still not mature enough to be the complete data source

Simulation tools have well defined principles and documentation for modelling the grid components

CIM documentation is not at the same level This leads to misinterpretations, which lead to wrong data

The lack of a short circuit and dynamics data model have

been a significant drawback Without this, a common CIM model will not work for planning

purposes

Experiences with merging different

models into a CIM-based model

As we all know, data verification is a long and never-ending story…

The following issues represent some of our main challenges in the merging project

Model merging – data quality AC LineSegment Data quality

Data attribute EMS Model

Planning model

Protection model

Source for Common model

r Good Good Good/ Medium

Planning

x Good Good Good Planning

b Good Good Good Planning

r0 Poor missing Good Protection

x0 Poor Missing Good Protection

b0 Poor Missing Good Protection

Topology Good Medium Medium EMS

Ratings Good Medium Missing EMS/Plan

Regulating Control (Taps, etc)

Medium Medium Poor EMS/Plan/ others

Model merging – different resolution

Typical topology level EMS Typical topology level PSS®E

A challenge that the planning model has aggregated loads and generation to higher voltage levels, while the EMS model goes further down

Model example – converting

operational model to planning model

• A model export based on breaker status will give changing model exports

• We need to have a standard planning case export

• This is achieved by two functions • BusNameMarker with priority • Retain switch

• "Retain switch" is used for

selecting whether one or two busbars will be exported

• The priority defines if busbar A or busbar B number is to be used if the two buses are merged into one TopologicalNode

Double busbar export

Single busbar export

Busbar A

Busbar B

Busbar A

Busbar B

Busbar A

Experiences with CIM model exchange

A CIM 14 and 15 compliant model today will not fulfil requirements for power system analysis beyond simple load flow Until the CIM standard is mature for all types of analysis, there will still be a

need for a lot of post-processing of data

The simplifications needed are making it difficult to use reimported models in analysis tools like PSS®E Some Examples:

Transformer Phase Shift for Delta Windings ignored in CIM 14 ShuntCompensators and RegulatingControls not possible to model according to our

control schemes => Solution from CIM no longer valid when reimporting the same model back to PSSE

CIM v16 is the first version with the potential to fulfil our requirements

for practical use But it requires that there is a focus on the practical use of the CIM standard

Some wishes for CIM 16 from

planning Dynamic model must allow for:

User defined models (30 % of our models) Mainly SIPS, Exciter and Stabilizer models

HVDC models

ShuntCompensator Models Must allow for unsymmetrical ShuntCompensation

RegulatingControl Must allow remote reactive control

Ratings Allow for different temperatures in schedules

In general: CIM needs a move in direction of being "planning friendly"

Status and remaining work for merging

Operational and Planning model Status:

Conversion from PSS®E to PSS®ODMS is operational with some limitations

Conversion from PSS®ODMS to PSS®E is operational, but with severe limitations

Existing EMS system can export base model to CIM version 13 Working on upgrading to export v15 with extensions

Remaining: Finalize model merging to a common model

Some issues must wait at least until CIM16 is available in the software

Post-processing standard scripts will be needed

Update database with planned projects to be able to export planning scenarios from PSS®ODMS to our planning tool

Thank you!

For more information about Statnett

www.statnett.no

And the CIM integration project

sigbjorn.sorbotten@statnett.no

svein.harald.olsen@statnett.no