Flexibility of the distribution grid for system stability

A new organisation and provision of frequency and voltage control are key elements for future power systems with large amount of renewable sources. This implies substantial challenges and new requirements for the electricity transmission as well as for the distribution system in order to ensure stable operation of the power system. The static voltage stability analyses of the German transmission system carried out in this paper confirm the need for further reactive power sources in Germany. Solutions for cost-efficient and technical reasonable concepts to provide reactive power considering contributions by transmission as well as distribution system will be introduced and evaluated. Additionally, for dynamic evaluation of innovative control concepts for frequency and voltage control a simulation framework is developed. Simulation results show that a system with conventional and innovative ancillary service providers as well as a combination of them can fulfill technical requirements.