Treatment of Transmission System Bottlenecks - Future Strategies at PreussenElektra Netz

Transcription

1 APX International Conference, November 1999 Amsterdam, The Netherlands Treatment of Transmission System Bottlenecks - Future Strategies at PreussenElektra Netz Markus Bredow Matthias Luther Germany

2 Contents Introduction Reasons for transmission system bottlenecks Methodologies for detection Analysis and evaluation Preferred technical and commercial solutions Summary

3 PreussenElektra Netz TSO in the Heart of Europe

4 Reasons for Transmission System Bottlenecks (1) - Comparison between monopoly and deregulated situation monopoly Transmission system design corresponds to the location of power plants TSO is responsible for system control and generation scheduling deregulation no influence of TSO on generation scheduling constraints due to various physical flows system improvements base on the existing grid today: relative uncertain boundary conditions in order to evaluate the system performance compared to the monopoly situation

5 Reasons for Transmission System Bottlenecks (2) - Technical Limits transfer capacity thermal limits local stability small signal stability

6 Precondition for Congestion Management - Data Provision among the German TSOs TSO 1 TSO 2 TSO 3... TSO n daily provision of network equivalents including actual network structure infeeds and loads common daily network data pool with full access for all TSOs individual evaluation of system performance by TSOs

7 Detection of Bottlenecks - System Control Features daily evaluation of the infeed/load schedule (today for tomorrow) considering internal bottlenecks and ATCs to neighbouring systems online load flow supervision transient and steady state stability evaluation by snapshot analysis

8 Definition of Transfer Capabilities P (MW) TRM TTC NTC ATC NTF T (Hours) source: ETSO

9 Major Demands on Congestion Management fair and non-discriminating economical efficient transparent cost-reflective secure and unambiguous feasible

10 Technical Measures to Increase Transfer Capacity improvement of existing lines, construction of new lines installation of additional transformer capacity phase shifting transformers (mobile) Flexible Alternating Current Transformation Systems (FACTS)

11 Preferred Methods for Congestion Management (1) Auctioning time horizon: long run until day ahead each market participant offers a price for use the NTCs priority rule for transactions: stacking of bids - highest first - until NTCs are saturated pricing: equal to the last accepted bid several congestion for one transaction needs some iterations for process convergence

12 Preferred Methods for Congestion Management (2) Market Splitting time horizon: typically day ahead theoretical basis: demand decreases in high price areas and increases in low price areas method: TSO controls counter-trading congestion charge: price difference between the downstream and the upstream area requires liquid spot trades in market areas

13 Preferred Methods for Congestion Management (3) Redispatching time horizon: day ahead until online requires costs for up and down modulation of generators 1st step: generators within the TSOs own control area 2nd step: cross-border coordinated redispatching costs are socialised

14 Summary Bottleneck Treatment detailed analysis of the system performance close cooperation between the TSOs concerned fair and non-discriminating combination of technical and commercial measures