Distributed real-time method for congestion management in electrical transmission systems considering HVDC-links and redispatch

• Applicant: Professor Dr.-Ing. Christian Rehtanz
• Subject Area: Electrical Energy Systems, Power Management, Power Electronics, Electrical Machines and Drives
• Term: from 2013 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 239343689

Due to the large-scale integration of renewable energy sources and transnational trade of electricity, the European transmission network will face significant network congestion both at cross-border interconnections and internally in national grids. At the same time, the transmission system operators (TSOs) are committed to operate the grid according to the N-1 criterion that requires the security of network operation for the loss of any single piece of equipment in any credible scenario. Uncertainties regarding the feed-in by wind and solar power increase the number and spread of these scenarios leading to curtailment of generation by the most economic power plants and renewable energy sources due to network restrictions.In order to alleviate this effect it can be accounted for counter-measures that can be executed to respond to the scenarios or loss of equipment and to reduce overloads in due time. In research centralized optimization approaches are proposed for this problem that result in suggestions for adequate topological counter-measures or reconfiguration of generation and load (redispatch). These approaches exhibit some disadvantages: in the European network no central entity obtains a complete system view (due to the existence of various TSOs), due to length of calculation the optimization cannot be executed in real-time for large-scale systems, and only N-1 but not arbitrary network situations (N-2 to N-k) are considered. For this reason, the following scientific problem needs to be addressed which will be addressed in this research project:How can overloads of network equipment be relieved robustly in real-time in case of incomplete system information and arbitrary network situations (N-1,N-2 to N-k)?The approach of this project builds on preliminary work of the project "Decentralized coordination of power flow controllers for increasing transmission capacity and security" in the course of DFG research unit FOR1511. In that project, a distributed real-time coordination system for AC power flow controllers has been developed that adapts to unforeseen network situations. Based on this it will now be investigated how power flow control by HVDC transmission technology can be integrated in the coordinated AC power flow control. In addition, basic research will be conducted to investigate how coordinated real-time redispatch can be achieved by a distributed system in order to deploy the flexibility at both generation and consumption side (e.g., electric vehicles, storages) to relieve overloads of network equipment in critical network situations.

• DFG Programme: Research Grants