Johannes Rolink

Large-Scale Modeling of Grid-Connected Electric Vehicles

This paper presents a methodology for modeling the load behavior of electric vehicles. This information is needed to make a more accurate prediction of the technical potential of electric vehicles which might be used in the future as dispersed energy storages or controllable loads. For this purpose, a simplified stochastic model is established based on nonhomogeneous semi-Markov processes. This model is capable of describing the grid connectivity of electric vehicles over the period of one day. In addition, it provides information about the driven distance and the state of charge. This makes it possible to generate information about the load behavior of the vehicles at different times and locations. The fundamentals of the model are given in this paper as well as the basic results. As proof of validation, a comparison between the results and real data are presented. Finally, a synthetic load profile is generated based on the proposed model.

Estimation of the availability of grid-connected electric vehicles by non-homogeneous semi-Markov processes

This paper presents a methodology to estimate the grid-availability of electric vehicles. This information is needed to make a more accurate prediction of the technical potential of electric vehicles which might be used in future as dispersed energy storages or controllable loads. For this, a simplified stochastic model is built up based on non-homogeneous semi-Markov processes. This model is capable of describing the grid connectivity of electric vehicles during the period of a day. Thereby it is possible to derivate information about the availability of the cars at different times and locations. The fundamentals of the model are given in this paper as well as the basic results. For the proof of validation, a comparison between the results of the model and real data is presented. Eventually, some further application areas of the model are discussed.

Capacity of low voltage grids for electric vehicles

In this paper a method is proposed to identify the grid capacity of low voltage grids concerning electric vehicles. The analysis is based on structural data and does not require detailed grid information. The methodology is exemplary applied to the city of Berlin. The paper discusses the impact of electric vehicles on the grid capacity. Charging curves as well as simultaneity factors are given. Further, the main boundary conditions restricting the grid capacity are regarded. Finally, some results are presented for Berlin.

Ladeinfrastrukturen für die Netzintegration von Elektrofahrzeugen

Zusammenfassung Zukünftig werden neben Dezentralen Energieumwandlungsanlagen (DEA) vermehrt auch Elektrofahrzeuge an das Niederspannungsnetz angeschlossen. In Zusammenhang mit der Netzintegration wird auch die Bereitstellung von Systemdienstleistungen diskutiert. Damit verbunden ist die Forderung, dass beim Laden der Fahrzeuge als auch bei einer Rückspeisung elektrischer Energie die Versorgungsqualität, Versorgungszuverlässigkeit und Sicherheit des Netzes nicht beeinträchtigt wird. Ein intelligentes Lademanagement ist vor dem Hintergrund eines Smart Grid unabdingbar. Abstract Beside renewable energy sources also the integration of electric vehicles has to be considered for future low voltage grids. Related to this, the application of electric vehicles for ancillary services is discussed. In order to charge the vehicles or to feed-back electricity to the grid, it is necessary to assure the quality, reliability and security of the system. An intelligent load management system is mandatory to realize these smart grid applications.