Publikationen

2021

• Coupled power plant and geostorage simulations of porous media compressed air energy storage (PM-CAES)

  Pfeiffer, W. T., Witte, F., Tuschy, I., & Bauer, S. (2021). Coupled power plant and geostorage simulations of porous media compressed air energy storage (PM-CAES). Energy Conversion And Management, 249, 114849. http://doi.org/https://doi.org/10.1016/j.enconman.2021.114849

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  Porous media compressed air energy storage (PM-CAES) systems that use porous geological formations such as sandstone may provide large storage capacities in future energy systems based primarily on fluctuating renewable energy sources. In CAES systems, the instantaneous power and stored energy are closely linked to the storage pressure and the mass flow rate achievable in the geological reservoir. Therefore, a coupled simulator that accurately represents the power plant, the geostorage site, and their interactions during all potential PM-CAES system operation modes is presented in this paper. Using adiabatic and diabatic power plant topology test designs, strong feedback between the achievable storage rates and capacities of the chosen power plant design and geostorage site are found, thus confirming the benefit of this integrated modelling approach. Using a generic, highly cyclic load profile for daily peak shaving with charging and discharging rates of 100 MW and an adiabatic power plant topology, it is found that all discharging targets can be met but the achievable charging rates decrease to approximately 95 MW due to increased pressure in the geostorage after approximately 10 cycles. When a diabatic power plant design is considered, a long-term decrease in the geostorage pressure is found. Correspondingly, the charging power always meets the specifications, while the discharging power decreases slowly from the 20th storage cycle onwards to 79 MW in the 31st cycle. The newly developed simulation tool thus allows one to predict achievable power rates and geostorage pressures for PM-CAES systems, enabling the identification of efficient PM-CAES designs.

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    • Witte, Francesco
    • Tuschy, Ilja

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  • 2021
  • Journal Article
  • • Wolf Pfeiffer
    • Francesco Witte
    • Ilja Tuschy
    • Sebastian Bauer
  • • PM-CAES
    • Compressed air energy storage
    • Geological storage
    • Coupled simulations

• Grid Support with Wind Turbines: The Case of the 2019 Blackout in Flensburg

  Gloe, A., Jauch, C., & Räther, T. (2021). Grid Support with Wind Turbines: The Case of the 2019 Blackout in Flensburg. Energies, 14(6), 1697. http://doi.org/10.3390/en14061697

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  The work presented in this paper aims to show how modern wind turbines can help to control the frequency in a small grid which suffers from large power imbalances. It is shown for an exemplary situation, which occurred in Flensburg’s distribution grid in 2019: a major blackout, which occurred after almost two hours in islanding operation, affecting almost the entire distribution grid, which supplies approximately 55,000 households and businesses. For the analysis, a wind turbine model and a grid support controller developed at the Wind Energy Technology Institute are combined with real measurements from the day of the blackout to generate a fictional yet realistic case study for such an islanding situation. For this case study, it is assumed that wind turbines with grid support functionalities are connected to the medium voltage distribution grid of the city. It is shown to what extent wind turbines can help to operate the grid by providing grid frequency support in two ways: By supplying synthetic inertia only, where the wind turbines can help to limit the rate of change of frequency in the islanded grid directly after losing the connection to the central European grid. In combination with the primary frequency control capabilities of the wind turbines (WTs), the disconnection of one gen set in the local power station might have been avoided. Furthermore, wind turbines with primary frequency control capabilities could have restored the grid frequency to 50 Hz shortly after the islanding situation even if the aforementioned gen-set was lost. This would have allowed connecting a backup medium voltage line to the central European grid and thereby avoiding the blackout.

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  • Personenseiten

    • Gloe, Arne
    • Jauch, Clemens

  • Forschungsprojekt

    • Grenzland INNOVATIV Schleswig-Holstein

  • Abteilung/Einrichtung

    • Wind Energy Technology Institute

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  • 2021
  • Journal Article
  • • Arne Gloe
    • Prof. Dr. Clemens Jauch
    • Thomas Räther
  • • WETI

• Adapting Behavior Driven Development (BDD) for large-scale software systems

  Irshad, M., Britto, R., & Petersen, K. (2021). Adapting Behavior Driven Development (BDD) for large-scale software systems. Journal Of Systems And Software, 177, 110944.

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    • Petersen, Kai

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  • 2021
  • Journal Article
  • • Mohsin Irshad
    • Ricardo Britto
    • Kai Petersen

• Development of a Lightweight Hydraulic-Pneumatic Flywheel System for Wind Turbine Rotors

  Alhrshy, L., Jauch, C., Schaffarczyk, A. P., & Bünning, N. (2021). Development of a Lightweight Hydraulic-Pneumatic Flywheel System for Wind Turbine Rotors. http://doi.org/10.13140/RG.2.2.13569.89447

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    • Alhrshy, Laurence
    • Jauch, Clemens

  • Abteilung/Einrichtung

    • Wind Energy Technology Institute

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  • 2021
  • Report
  • • Laurence Alhrshy
    • Prof. Dr. Clemens Jauch
    • A. Schaffarczyk
    • N. Bünning
  • • WETI

• Delegating Supersingular Isogenies over F_p^2 with Cryptographic Applications

  Pedersen, R., & Uzunkol, O. (2021). Delegating Supersingular Isogenies over F_p^2 with Cryptographic Applications. Iacr Cryptol. Eprint Arch., 2021, 506. Abgerufen von https://eprint.iacr.org/2021/506

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  • Personenseiten

    • Uzunkol, Osmanbey

  • Fachbereich

    • Fachbereich 3: Information und Kommunikation

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  • 2021
  • Journal Article
  • • Robi Pedersen
    • Osmanbey Uzunkol

• Preliminary Evaluation of a Survey Checklist in the Context of Evidence-based Software Engineering Education.

  Petersen, K., & eri, J. S. M. \. (2021). Preliminary Evaluation of a Survey Checklist in the Context of Evidence-based Software Engineering Education. In ENASE (S. 437-444).

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    • Petersen, Kai

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  • 2021
  • Conference Paper
  • • Kai Petersen
    • Jefferson eri

• Exploration vs. limitation – An investigation of instructional design techniques for spatial ability training on mobile devices

  Montag, M., Bertel, S., de Koning, B. B., & Zander, S. (2021). Exploration vs. limitation – An investigation of instructional design techniques for spatial ability training on mobile devices. Computers In Human Behavior, 118, 106678. http://doi.org/https://doi.org/10.1016/j.chb.2020.106678

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  Spatial abilities and thus mental rotation skills predict achievement in STEM domains. Thus, a wide range of studies investigated the possibilities and trainings of mental rotation skills. One prominent approach is using different digital tools and representation formats to foster spatial abilities. Thereby numerous studies analyzed effects of static in comparison to interactive dynamic representations of mental rotation tasks using different types of interactions. Although the use of dynamic representations is discussed critical regarding superficial information processing, there are no studies to date varying instructional techniques in interactive dynamic spatial trainings. In two studies we compared Limited Rotation training to non-limited Free Rotation training with high school students (Npilot = 21, Nmain = 66). Results after training show a superior effect of the limited compared to the non-limited training regarding the students’ success rate, but not their motivation and mental demand. Additionally analyzed process data show more efficient ways of task solving after limited rotation training indicated by reduced response time and rotation way accompanied by higher success rates in solving non-limited rotation tasks. Results of a pre-and-post-comparison of mental rotation skills indicate a higher increment after limited rotation training. Over-facilitating effects of dynamic representations are discussed.

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  • Personenseiten

    • Bertel, Sven

  • Abteilung/Einrichtung

    • CIVU – Center for Interaction, Visualization and Usability

  • Fachbereich

    • Fachbereich 3: Information und Kommunikation

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  • 2021
  • Journal Article
  • • Michael Montag
    • Sven Bertel
    • Bjorn de Koning
    • Steffi Zander
  • • Spacial abilities
    • STEM
    • Multimedia learning
    • mental rotation

• Influence of Continuous Provision of Synthetic Inertia on the Mechanical Loads of a Wind Turbine

  Gloe, A., Jauch, C., Craciun, B., Zanter, A., & Winkelmann, J. (2021). Influence of Continuous Provision of Synthetic Inertia on the Mechanical Loads of a Wind Turbine. Energies, 14(16), 5185. http://doi.org/10.3390/en14165185

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  In many electrical grids, the share of renewable energy generation increases. As these generators are typically connected to the grid via inverters, the level of grid inertia decreases. Such grids may therefore suffer from high rates of change of frequency during power imbalances. Modern wind turbines can help in controlling the frequency in such grids by providing synthetic inertia. A controller to provide synthetic inertia with wind turbines was developed at the Wind Energy Technology Institute in collaboration with Suzlon Energy. For this controller the influence of providing synthetic inertia on the mechanical loads of the wind turbine is assessed for different grid frequency scenarios. Such a scenario-based load analysis has not been published before, especially as the scenarios are derived from real measurements. The effect of the loads strongly depends on the analyzed grid frequency behavior. Ten months of high quality grid frequency measurements of the Indian grid are analyzed in order to derive inputs for the load calculation. Different types of grid frequency abnormities are identified and categorized with respect to their severity. Based on the observed occurrences of the grid frequency abnormities, realistic scenarios for the load calculations are chosen. The load calculations are performed for a state-of-the-art Suzlon wind turbine generator. The load increases caused by the supply of synthetic inertia are calculated for individual components assuming an otherwise undisturbed power production of the wind turbine in turbulent wind. Furthermore, a hardware-in-the-loop test bench is used to show how the measured grid frequencies are actually perceived by the control system of a typical wind turbine. The original frequency data were recorded with high quality measurement equipment, which is faster and more accurate than a multi-function relay, often used in wind turbines. For exemplary time traces, the effect of the reduced measurement accuracy on the reaction of the wind turbine is shown. This aspect has not been investigated in the literature yet. The results show that wind turbines can provide synthetic inertia without a considerable effect on the lifetime of the wind turbine. However, there are still problems with providing synthetic inertia reliably at high power operating points, which have to be solved.

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    • Gloe, Arne
    • Jauch, Clemens

  • Abteilung/Einrichtung

    • Wind Energy Technology Institute

  • Fachbereich

    • Fachbereich 2: Energy and Life Science

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  • 2021
  • Journal Article
  • • Arne Gloe
    • Prof. Dr. Clemens Jauch
    • B. Craciun
    • Arvid Zanter
    • J. Winkelmann
  • • WETI

• Kompetenzen für eine digitale Welt

  Bertel, S., Beck, L., Clausen, B., & Räker, T. (2021). Kompetenzen für eine digitale Welt. Wie viel Wissenschaft braucht die Lehrerfortbildung? Arbeitsbündnisse im analogen und virtuellen Raum. Universität Regensburg.

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    • Bertel, Sven

  • Abteilung/Einrichtung

    • CIVU – Center for Interaction, Visualization and Usability

  • Fachbereich

    • Fachbereich 3: Information und Kommunikation

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  • 2021
  • Conference Proceedings
  • • Sven Bertel
    • Lena Beck
    • Bernd Clausen
    • Timo Räker

• Feature selection techniques for modelling tower fatigue loads of a wind turbine with neural networks

  Movsessian, A., Schedat, M., & Faber, P. D. -I. T. (2021). Feature selection techniques for modelling tower fatigue loads of a wind turbine with neural networks. Wind Energy Science. http://doi.org/https://doi.org/10.5194/wes-6-539-2021

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  • Personenseiten

    • Faber, Torsten

  • Abteilung/Einrichtung

    • Wind Energy Technology Institute

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  • 2021
  • Journal Article
  • • A. Movsessian
    • M. Schedat
    • Prof. Dr.-Ing. Torsten Faber
  • • WETI