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Jauch C.,Flensburg University of Applied Sciences
Wind Engineering | Year: 2016

In this article, the control strategy for a previously proposed flywheel system that is integrated in a wind turbine rotor is presented. This control strategy allows the flywheel system to serve two purposes: support of the frequency in the grid and mechanical load mitigation in the wind turbine. For the first purpose, extra energy is fed into the grid whenever there is a contingency; alternatively, the varying power output from the wind turbine can be stabilized. For the latter purpose, the flywheel is applied to detune the eigenfrequency of the most vibratory components in a wind turbine, that is, the rotor blades. Simulations are shown to illustrate the principle and the performance of the proposed system. It is concluded that the controls of the flywheel system manage to support the grid frequency and also mitigate mechanical vibrations in different operating points of the wind turbine. © The Author(s) 2016. Source


Jauch C.,Flensburg University of Applied Sciences
Wind Engineering | Year: 2014

In this article a wind model is presented that allows simulation of realistic wind speeds over the area of a wind farm. The primary propose of this model is power system simulations, where fast simulation speed is crucial, and where it is undesirable to use different tools to run a simulation. The proposed wind model combines the too simple wind models commonly used in power system simulations of wind turbines and a sophisticated wind model that represents the different wind speeds that occur across a wind turbine rotor. The result is a farm wind model for simulating the power system behaviour of a wind farm. Source


Zachow M.,Flensburg University of Applied Sciences
CEUR Workshop Proceedings | Year: 2016

Mobile applications (apps) are increasingly popular and run on a wide range of different operating systems and devices. Fragmentation is one of the differences between mobile apps and web-or desktop based applications and presents a challenge in delivering high quality apps. Automated testing can help to overcome it. This paper presents a case study on designing a continuous delivery pipeline for an Android app focused on simple setup. © Copyright 2016 for the individual papers by the papers' authors. Source


Enning B.,Flensburg University of Applied Sciences
Frequenz | Year: 2011

Two new configurations for the realization of two-tap transversal filters in 50 ω. delay line technique with cosine and sine frequency responses are proposed. Examples are given for the conversion of nonreturn-to-zero signals into partial response signals with duobinary, bipolar, and modified duobinary shape which can be applied in electrical and optical transmission systems. Calculated and measured results for Gbit/s signal processing are compared. Copyright © 2011 De Gruyter. Source


Jauch C.,Flensburg University of Applied Sciences
Wind Energy | Year: 2015

In this paper, a flywheel energy storage that is an integral part of a wind turbine rotor is proposed. The rotor blades of a wind turbine are equipped with internal weights, which increase the inertia of the rotor. The inertia of this flywheel can be controlled by varying the position of the weights, i.e. by positioning them closer to the center of rotation (closer to the hub) or closer to the tip of the blades. The simulation model used in this study is introduced briefly. The equation system of the flywheel is set up. Finally, simulations of different scenarios show the performance of this controllable flywheel. The conclusion is that the proposed system can mitigate transients in the power output of wind turbines. Hence, it can support the frequency control in a power system by contributing to the power system inertia. Copyright © 2014 John Wiley & Sons, Ltd. Source

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