Publikationen

Hydraulic variable inertia flywheel

Jauch, C. ., Jost, R. ., & Kloft, P. . (2024). Hydraulic variable inertia flywheel. Applied Energy, 360, 16. http://doi.org/https://doi.org/10.1016/j.apenergy.2024.122830 (Original work published Februar 2024)

Abstract

A novel variable inertia flywheel that uses the mass of a rotating hydraulic fluid is proposed in this paper. In contrast to variable inertia flywheels that use solid masses, this flywheel stands out for its simplicity. In contrast to many other common energy storages, it does not require any environmentally harmful, rare or expensive materials. The basic working principle and the equations that cover the hydraulic behaviour, the pneumatic behaviour and the energy from angular momentum are introduced. These equations are applied to the geometry of the proposed flywheel concept, which allows quantifying the pressures that act on the different mechanical flywheel components. These pressures, together with the centrifugal acceleration from rotation, lead to the loads that have to be withstood by the mechanical components. A simple method for quantifying these loads, and for dimensioning the mechanical components, allows deriving the stationary masses and inertias. A parameter study is conducted, in which different parameters of the flywheel are varied in order to find the maxima in energy density and specific energy. The results of this parameter study reveal that the proposed hydraulic variable inertia flywheel is a very simple and safe energy storage that could provide AC power systems with inertia and control power to support their frequency.
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Jauch, Clemens
- Forschungsprojekt
  
  Inno!Nord: Innovationslabor: Speicher zur Nutzung erneuerbarer Energien im echten Norden
- Abteilung/Einrichtung
  
  Wind Energy Technology Institute
- Profilbereich
  
  Erneuerbare Energien und nachhaltige Entwicklung
- Forschungsfeld
  
  Innovation und Wachstum, Nachhaltigkeit
  
  Wind
  
  Netzintegration
- Fachbereich
  
  Fachbereich 2: Energy and Life Science
Filter Tags
Atmospheric Irrigation with Wind Turbines

Jauch, C. ., & Emeis, S. . (2022). Atmospheric Irrigation with Wind Turbines. Journal of Physics: Conference Series, 2265, 042066. http://doi.org/10.1088/1742-6596/2265/4/042066 (Original work published 2024)

Abstract

In this paper, atmospheric irrigation with wind turbines is proposed. This technology addresses the problem of water scarcity by enhancing the natural water circuit in the atmosphere with wind turbines. There are three different operating modes conceivable for this technology. In two of these the wind turbines interact with the ground in their near wake. The third operating mode is the one which is discussed in this paper, and it aims at transporting water potentially over long distances. The basic working principle, the utilized physical phenomena and the basic design of the technology are introduced. The equations governing the hydraulic and the hydrological effects are presented. The goal of this paper is to quantify the necessary power and the necessary amount of water when wind turbines humidify a certain volume of air in the atmosphere. For this purpose, the power and water demand are assessed, both in a generalized manner and for a realistic scenario. It is concluded that the proposed system can achieve the objective in most wind speed conditions. However, the required amount of water is substantial. Therefore, an alternative source of fresh water has to be found when the system is used on a comparably large scale.
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Jauch, Clemens
Filter Tags
A Resource-Efficient Design for a Flexible Hydraulic-Pneumatic Flywheel in Wind Turbine Blades

Alhrshy, L. ., & Jauch, C. . (2022). A Resource-Efficient Design for a Flexible Hydraulic-Pneumatic Flywheel in Wind Turbine Blades. Journal of Physics: Conference Series, 2265, 032018. http://doi.org/10.1088/1742-6596/2265/3/032018 (Original work published 2024)

Abstract

The utilization of renewable energy resources significantly increases in order to reduce the impact of climate change. Wind turbines are one of the most important renewable energy sources and have an important role to play in power generation. They do, however, have to serve the increasingly variable demands of the grid. Some of these demands cannot be satisfied with the standard control mechanisms of state-of-the-art wind turbines. A hydraulic-pneumatic flywheel in a wind turbine rotor is one mechanism which, in addition to its various grid services, can also reduce the mechanical loads on the structure of a wind turbine. However, the installation of such a flywheel into rotor blades increases the weight of the blades. This paper focusses on the development of a design method for reducing the additional mass of the flywheel. This method incorporates the piston accumulators of the flywheel in the blade support structure, which allows for the replacement of parts of the blade spar caps with composite material from the piston accumulators. This enables the flywheel to be installed into the rotor blades without making the wind turbine significantly heavier.
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Jauch, Clemens
Filter Tags
Netzintegration von Windenergieanlagen

Jauch, C. . (2022). Netzintegration von Windenergieanlagen. In Einführung in die Windenergietechnik (3. Aufl., S. 407–471). München: Carl Hanser Verlag. http://doi.org/10.3139/9783446473225.010 (Original work published April 2022)
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Jauch, Clemens
- Fachbereich
  
  Fachbereich 2: Energy and Life Science
Filter Tags
Potential of Onshore Wind Turbine Inertia in Decarbonising the Future Irish Energy System

Thiesen, H. ., & Jauch, C. . (2022). Potential of Onshore Wind Turbine Inertia in Decarbonising the Future Irish Energy System. Applied Sciences, 12(6), 16. http://doi.org/10.3390/app12062984 (Original work published März 2021)

Abstract

Power system inertia is an essential part for grid frequency stability and decreases due to the replacement of fossil fuel fired power plants with variable renewable energy sources. This development is not represented sufficiently in unit commitment and economic dispatch models. If considered at all, only synchronous inertia from fossil fuel driven power plants is modelled. This results in increased CO2 emissions, curtailed renewable energy and high system costs. While wind turbines are a source for synthetic inertia and an important renewable energy source, their capability to provide inertia is not incorporated into energy system models. The work at hand closes this research gap and applies a methodology to depict synthetic inertia provided by wind turbines as part of the optimisation dispatch model. A unit commitment and economic inertia dispatch model of the the all-Island Irish power system is created. The potential of wind inertia is analysed and quantified by assessing CO2 emissions, curtailed renewable energy and system costs. Results show that synthetic inertia provided by wind turbines can save up 30.99% of the CO2 emissions, reduce curtailment by up to 39.90% and reduce system costs by 32.72%.
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Thiesen, Henning
  
  Jauch, Clemens
- Abteilung/Einrichtung
  
  Wind Energy Technology Institute
- Fachbereich
  
  Fachbereich 2: Energy and Life Science
Filter Tags
Application of a New Dispatch Methodology to Identify the Influence of Inertia Supplying Wind Turbines on Day-Ahead Market Sales Volumes

Thiesen, H. ., & Jauch, C. . (2021). Application of a New Dispatch Methodology to Identify the Influence of Inertia Supplying Wind Turbines on Day-Ahead Market Sales Volumes. Energies, 14(5). http://doi.org/10.3390/en14051255 (Original work published Februar 2021)

Abstract

Power system inertia is an essential part of grid frequency control. The number of synchronously connected machines, which inherently provide inertia, is decreasing due to the transition to renewable energies. Conventional generation units are being replaced by renewable generation units which are connected to the grid via frequency converters. Some power systems already suffer from too little power system inertia. Hence, inertia is a valuable yet non-traded commodity. A day-ahead dispatch methodology to secure power system inertia was developed and is applied and assessed in this work. Day-ahead market data of the combined market of the Republic of Ireland and Northern Ireland is used. If the superimposition of sell and buy bids results in insufficient inertia, the dispatch algorithm is applied. In decreasing price order, non-inertia-providing sell bids get replaced by the following sell bids in the merit order. The iterative process is repeated until sufficient inertia is in the system. The provision of synthetic inertia by wind turbines is considered in the process. The costs for additional stored kinetic energy for the assessed time periods and scenarios result in costs ranging from 1.02 to 4.49 EUR/kgm2.
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Thiesen, Henning
  
  Jauch, Clemens
- Abteilung/Einrichtung
  
  Wind Energy Technology Institute
Filter Tags
Grid Services and Stress Reduction with a Flywheel in the Rotor of a Wind Turbine

Jauch, C. . (2021). Grid Services and Stress Reduction with a Flywheel in the Rotor of a Wind Turbine. Energies, 14. http://doi.org/10.3390/en14092556

Abstract

Wind power penetration increases in most grids and the sizes of wind turbines increase. This leads to increasingly tough requirements, which are imposed on wind turbines, both from the grid as well as from economics. Some of these partially contradictory requirements can only be satisfied with additional control mechanisms in the wind turbines. In this paper, such a mechanism, i.e., a hydraulic–pneumatic flywheel system in the rotor of a wind turbine, is discussed. This flywheel system supports a wind turbine in providing grid services such as steadying the power infeed, fast frequency response, continuous inertia provision, power system stabilization, and low voltage ride-through. In addition, it can help mitigate the stress on the mechanical structure of a wind turbine, which results from varying operating points, imbalances in the rotor, gravitation that acts on the blades, in-plane vibrations, and emergency braking. The study presented in this paper is based on simulations of a publicly available reference wind turbine. Both the rotor blade design as well as the design of the flywheel system are as previously published. It is discussed how the aforementioned grid services and the stress reduction mechanisms can be combined. Finally, it is concluded that such a flywheel system broadens the range of control mechanisms of a wind turbine substantially, which is beneficial for the grid as well as for the wind turbine itself.
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Jauch, Clemens
- Fachbereich
  
  Fachbereich 2: Energy and Life Science
Filter Tags
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

Abstract

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.
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Gloe, Arne
  
  Jauch, Clemens
- Abteilung/Einrichtung
  
  Wind Energy Technology Institute
- Fachbereich
  
  Fachbereich 2: Energy and Life Science
Filter Tags
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

Abstract

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.
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Gloe, Arne
  
  Jauch, Clemens
- Forschungsprojekt
  
  Grenzland INNOVATIV Schleswig-Holstein
- Abteilung/Einrichtung
  
  Wind Energy Technology Institute
Filter Tags
Grid Frequency Data – WETI

Thiesen, H. ., Gloe, A. ., & Jauch, C. . (2021). Grid Frequency Data – WETI. http://doi.org/doi.org/10.17605/OSF.IO/JBK82

Abstract

The presented grid frequency data is part of research activities at the Wind Energy Technology Instiute (WETI) at the Flensburg University of Applied Sciences. The measurement campaign is conducted in Flensburg, Germany. Hence, the grid frequency of the synchronous area of Continental Europe is tracked. A Dewetron 2010 measurement system is used to record and compute the data. The measurement system computes the grid frequency by tracking the grid voltage with a high sampling rate of 50 kHz. Every 164 ms the software fits a sinusoidal curve into the recorded voltage measurement points using the least-square-sums approach. The period of the resulting sinusoidal function is used as a measure for grid frequency.
- Suche auf Google Scholar
- DOI Verweis
Exportformate
Weiterführende Links
- Personenseiten
  
  Thiesen, Henning
  
  Gloe, Arne
  
  Jauch, Clemens
- Abteilung/Einrichtung
  
  Wind Energy Technology Institute
- Fachbereich
  
  Fachbereich 2: Energy and Life Science
Filter Tags

Publikationen

Abstract

Exportformate

Weiterführende Links

Filter Tags

Abstract

Exportformate

Weiterführende Links

Filter Tags

Abstract

Exportformate

Weiterführende Links

Filter Tags

Exportformate

Weiterführende Links

Filter Tags

Abstract

Exportformate

Weiterführende Links

Filter Tags

Abstract

Exportformate

Weiterführende Links

Filter Tags

Abstract

Exportformate

Weiterführende Links

Filter Tags

Abstract

Exportformate

Weiterführende Links

Filter Tags

Abstract

Exportformate

Weiterführende Links

Filter Tags

Abstract

Exportformate

Weiterführende Links

Filter Tags