Konrad PurchalaTractebel Engineering

Network modelling and power flow

simulations Lessons learned

EWEC conference - TradeWind18.3.2009, Marseille

Grid modeling

Objectives of the TradeWind study• Investigate power flows across Europe• Effect of moving weather conditions• Identify main bottlenecks

Context• Europe is zonal markets• National networks developed to be cooper

plates• Main structural bottlenecks at national frontiers

Note: issue of network data availability

4000+ nodes

6000+ lines

UCTE grid – the modeling challenge

Aggregated interconnection model

Physical cross-border lines model

Physical cross-border lines

model+

Grid modeling

Dilemmas• Can we get the detailed model from the TSOs?• Robustness of the model?

– solving 8760 hourly snapshots, data processing

• Location of generation, wind farms, demand?• Temporal variations of the demand?• Budget?

The chosen approach• Public grid model• Only cross-border constraints• DC power flow• At the end of the project, grid model available from the

TSOs

Grid modeling (example of UCTE)

Grid representation UCTE

DC power flow

orPTDF-solution

Comparison UCTE vs TradeWind

Approx. UCTE Detailed UCTE

bus total 1381 4339

generator buses 568 943

load buses 984 2317

total branches 2211 7292

lines 2211 6201

transformers 0 1091

hvdc 12 12

Modeling issues

Transmission bottlenecks• Anticipated main bottlenecks

– Detailed task in the project – Cross-country analyses

• All relevant bottlenecks should be included– Surely cross-border– For some countries also internal lines

• Future network reinforcements• Modeling of wind farms

– Correlation with the wind speed data– Grid connection?

• Treatment of hydro power– Water reservoir levels

Main lessons learned

• TradeWind changed the scene for integration studies

– Breakthrough on data availability– UCTE research model now available– Fruitful collaboration with the TSOs

• Methodology and data for future integration studies– Hour-by-hour investigations covering multiple years– Huge database of wind speeds, conversion curves, wind

capacity expansion scenarios, etc

• Large scale market simulations with grid constraints

– Allowing for more realistic results

Questions?