Auswirkungen der Elektromobilität auf die Niederspannungsebene

Translated title of the contribution: Impacts of electromobility on the low-voltage level

Bernd Thormann

Research output: ThesisMaster's Thesis

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Abstract

While electromobility is an important cornerstone of the initiated energy revolution, it certainly leads to new challenges for grid operators. An increasing penetration of electric vehicles results in raising loads at the low-voltage level and enhance the necessity of grid extensions. The consequences of single-phase charging for the low-voltage level are demonstrated for different penetration rates in order to prevent or delay these expansion measures. Additionally, these consequences should be counteracted by developing several approaches. The impact of an increasing penetration of electric vehicles on the low-voltage level is analysed on the basis of a real urban power grid operated by Energienetze Steiermark GmbH. Therefore, future electric vehicle numbers are considered by the use of measured charging curves of a modern car model. The analysis of grid loads in terms of voltage drops, line utilisation and unbalance triggered by single-phase charging is executed by load flow simulations based on the software NEPLAN in order to identify critical grid areas. These areas should be relieved by the use of Demand Side measures, the application of energy storages in combination with photovoltaic systems and the implementation of a variable transformer. Temporal deviations regarding charging processes within the low-voltage grid are taken into account by the use of simultaneity factors, which are determined by means of a probabilistic approach and real mobility data from Austria. Single-phase charging cause excessive unbalance in combination with voltage range deviations even for a penetration of 20 % and should therefore be replaced by three-phase charging. The first critical voltage drops in case of a uniform phase distribution occur in a numerous number of nodes within the longest feeder with a penetration of 60 % electric vehicles. Simultaneously, this results in the overloading of one grid line due to the great number of electric vehicles. The comparison of all the examined scenarios illustrates, that critical grid areas could be discharged especially by Demand Side measures and the use of a variable transformer. As a result, even a hundred percent electromobility penetration could be integrated in the analysed low-voltage grid without conventional grid extensions by the consideration of mentioned measures.
Translated title of the contributionImpacts of electromobility on the low-voltage level
Original languageGerman
QualificationDipl.-Ing.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Vopava-Wrienz, Julia, Co-Supervisor (internal)
  • Kienberger, Thomas, Supervisor (internal)
Award date15 Dec 2017
Publication statusPublished - 2017

Bibliographical note

no embargo

Keywords

  • electromobility
  • low-voltage grid
  • load flow analysis
  • solution strategies

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