Investigating the impact of large-scale deployment of EVs on the power system
Power systems can be of paramount complexity, especially on a large-scale with a huge amount of interconnected energy chains. As complexity increases, traditional architectures of power systems reach their limits. This problem can be compounded by a large scale transition to electro-mobility due to the impact of the charging infrastructure [1-3]. Thus traditional power systems are succeeded by smart grids that have diverse, intermittent and decentralized energy sources; these form distributed power systems which are controlled in a decentralized and autonomous fashion. Modeling and simulation is necessary in order to understand and plan the functionality of such complex power systems. Traditional tools, however, haven't been developed with this complexity in mind; thus, new design approaches are required.
Future scenarios of complex power systems call for new platforms that not just enable independent power system analyses but also the simultaneous analysis of the different systems (e.g. electric traffic system) having a significant impact on the power system. It is in this context that the Scalable Electro-Mobility Simulation (SEMSim) platform is currently being developed at TUM CREATE. Within this framework multiple simulation federates are coupled by means of using the IEEE standard 1516-2010 High Level Architecture (HLA). The two main federates, an agent-based, discrete-event traffic simulation (SEMSim Traffic) and a time-stepped power system simulation (SEMSim Power) , are used to investigate the impact of electro-mobility on the city infrastructure. SEMSim Power simulates the power flow of an entire city on the different voltage levels. As accurate information on a city’s power grid topology is often unavailable, SEMSim Power also comprises a method for synthesizing the power grid from tempo-spatially resolved power demand data.
The traffic system and the power system affect each other by means of charging and discharging of vehicle batteries at charging stations distributed across the city. This relation is illustrated the video shown at the end of the article. Depending on the charging station distribution and the dynamics of the traffic participants in terms of charging behavior, the dynamics of power demand are investigated in various electro-mobility scenarios. These studies are mainly concerned with establishing a better understanding of how disruptive city-wide electro-mobility (tens to hundreds of thousands of electric vehicles) may be with respect to utilization of buses and branches with the power system and their potential for being overloaded.
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 Shi, R. and Zhang, X.P. and Kong, D.C. and Deng, N. and Wang, P.Y., "Dynamic impacts of fast-charging stations for electric vehicles on active distribution networks", 2012 IEEE Innovative Smart Grid Technologies - Asia, ISGT Asia 2012 (2012).
 Dharmakeerthi, C.H. and Mithulananthan, N. and Saha, T.K., "Impact of electric vehicle fast charging on power system voltage stability", International Journal of Electrical Power and Energy Systems (2014), 241-249.