Investigation of seasonal congestion situations in modern rural integrated distribution grids

Abstract

In the Paris climate agreement, the international community has committed to limit global warming. In order to achieve this, the German government is taking considerable effort in transforming the energy system from a fossil-fuel-based system into a sustainable system relying on renewable energy sources. In todays energy systems the share of intermittent and distributed renewable generation is therefore rising rapidly. At the same time minimizing the transformation cost is necessary, while securing supply safe and economic optimality in operation. To achieve this balancing act, stakeholders follow the NOXVA principle, meaning grid optimization before flexibility before reinforcement before expansion, leading to the integration of the different energy sectors, electricity, gas and heat and also mobility. The accompanying shift in demand for example induced through electric vehicles and heat pumps is bound to stress especially the electrical distribution grids making grid bottlenecks in form of congestions considerably more likely. In this paper the authors contribute their findings regarding the investigation of season-dependent congestion situations in modern and future rural medium and low voltage grids, while taking into consideration the interface technologies of those multi-modal energy systems. The distribution grid, consisting of a medium voltage grid with highly-detailed subdivided bottom-up modeled low voltage grids, is modeled based on the open-source TransiEnt-Library for dynamic modeling of multi-modal energy systems. The congestion situation in favourable and less favourable situations, for example moderate and low outdoor temperatures, is represented and evaluated. First results of the simulation show that severe congestions occur especially under severe ambient conditions with consequently high simultaneous energy demand.