Spatial Effects of Flexibility Activation–Case Study of a Real-Life Hungarian Distribution Network

Abstract

As distributed energy sources, energy storage and electric vehicles are spreading, active consumers have appeared, flexibility is playing an increasingly important role in tackling emerging distribution network congestion problems. Applying flexibility can be a cost-effective way to manage such challenges, and it can help to defer grid developments. The purpose of this paper is to present a modeling framework that can help test the operation of flexibility products that may be applied to a distribution network. The load flow based simulations using representative sample networks from Hungary were aimed at solving two selected network problems by a flexibility service, mapping a potential product providing compensation for voltage drop on medium voltage overhead lines and reducing load on the substation’s transformer. As a result of the simulations, spatial contribution factors according to topological location were determined based on sensitivity, and their variability was studied by time sweep analysis on the two different products. A scenario considered the appearance of distributed generation and showed the effects on contribution factors. The variation of the contribution factors due to different loading and distributed generation differs by an order of magnitude in the two different products, due to the parameters of the overhead medium voltage networks. This means that in some use cases– as this long overhead medium voltage line’s voltage drop issue is a practical example– the variation of spatial effects due to different loading is not negligible, which should be considered in the development of flexibility need and activation calculations.

Keywords

• Flexibility
• distribution network
• congestion management
• distributed energy resources
• flexibility market