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Now showing items 11-20 of 120
Konferenzveröffentlichung
Fast parallel quasi-static time series simulator for active distribution grid operation with pandapower
(IET, 2021)
The increasing penetration from intermittent renewable distributed energy resources in distribution grid brings along challenges in grid operation and planning. To evaluate the impact on the grid voltage profile, grid losses, and discrete actions from assets (e.g. transformer tap changes), quasi-static simulation is an appropriate method. Quasi-static time series and Monte-Carlo simulation requires a tremendous number of power flow calculations (PFCs), which can be significantly accelerated with a parallel High-Performance ...
Dissertation
Entwicklung und Herstellung eines Labor-Demonstrators für Mikrospiegel-Arrays zur Tageslichtlenkung
(2018-05)
Die Entwicklung und Herstellung eines Labor-Demonstrators für Mikrospiegel-Arrays zur Tageslichtlenkung wird beschrieben. Der Labor-Demonstrator besteht aus einem aktiven Fenster und einem Miniaturraum, wodurch die Funktionsweise der Mikrospiegel-Arrays in dem aktiven Fenster optimal dargestellt werden kann. Das aktive Fenster besteht aus einer Isolierverglasung mit einer Größe von 50 cm x 50 cm, in deren Scheibenzwischenraum vier unabhängig voneinander steuerbare Mikrospiegel-Arrays integriert sind, die eine Fläche ...
Konferenzveröffentlichung
Controlled magnetic devices in power electronic applications
(IEEE, 2017)
Almost all power electronic converters require magnetic devices and some properties of the converters can be controlled with magnetics. New magnetic materials enable implementation of magnetic control of converters also in high switching frequency applications. The presented paper gives an overview about controllability of magnetic devices in theory and practice, simulation approaches and examples. The focus is on electrically controllable magnetic devices. This means that an additional control winding is wound on ...
Konferenzveröffentlichung
Design of Photovoltaic Microinverter for Off-Grid and Grid-Parallel Applications
(VDE Verlag, 2014)
The design and construction of a 500VA microinverter for photovoltaic applications is presented. The developed microinverter is capable of operating as a standalone AC voltage source for small loads or, alternatively, as a grid-parallel system. Possible applications are therefore small off-grid installations as well as installations where space constraints do not allow enough modules to be combined to use string inverters. The design of the microinverter is based on a two stage concept. Two alternative topologies for ...
Dissertation
Safety Approach of Detecting Abnormal Events (Spinning and Sliding) in Vehicular Systems
(2021)
The primary theme in the vehicles industry is the increase in automating and integrating more robust intelligent electronic systems to enhance the safe functioning, flexibility, and to extend the virtual productive age of the vehicular systems. Further, significant efforts focus on developing monitoring systems for the abnormal driving conditions such as wheel spinning and sliding that can increase the hazardous in the operating environment and speed up the wearing off process. Thus, these events play a primary role ...
Aufsatz
Review of Flux Interaction of Differently Aligned Magnetic Fields in Inductors and Transformers
(2020-12-24)
Magnetic devices are used in the majority of power electronic applications, e.g. power electronic converters, mains filters or burst/surge protection. Typically, they are the bulkiest and most cost-intensive components. Flux interaction of differently aligned magnetic fields in inductors and transformers can be one opportunity for size and cost reduction. It enables controllable magnetic devices through an additional manipulated variable to improve application design. The presented article gives an overview about ...
Dissertation
Ein Sensornetz zur Vermessung des Magnetfeldes am KATRIN Hauptspektrometer
(2019)
Das KARlsruhe TRItium Neutrino Experiment gilt als die genaueste Waage der Welt und hat sich der Aufgabe verschrieben die Masse des elektronischen Anti-Neutrinos mit einer Unsicherheit von m = 0:2 eV/c2 zu messen. Das Funktionsprinzip des eingesetzten Spektrometers erfordert eine genaue Kenntnis des Magnetfeldverlaufes im Inneren des Spektrometers. Aufgrund der Forderung nach einem extrem guten Vakuum ist eine direkte Messung des Magnetfeldes jedoch unmöglich. Die vorliegende Arbeit zeigt eine effektive Lösung auf ...
Dissertation
A scenario approach to modeling land-use changes and assessing associated environmental impacts in Southern Amazonia
(2017-03)
Humanity has left its footprint on the surface of the earth since it managed to purposefully employ tools and fire to its specific needs. Especially the conversion of natural habitats into agricultural productive land has transformed close to forty percent of the natural land-cover in order to satisfy global demands for food, raw materials, and energy. One current example of dynamic land-use and land-cover changes can be witnessed in Southern Amazonia. Spatially explicit land-use change models are applied to investigate ...
Dissertation
Understanding Factors Influencing the Performance of a Wi-Fi Fingerprinting System
(2019)
Location information plays a vital role in today’s society. People usually carry their mobile devices everywhere they go to benefit from real-time location services; the location of the device is the location of users. The focus of positioning services is shifting from outdoors to indoors. Technological services which depend on indoor locations are increasing in popularity. Wi-Fi fingerprinting is a promising technique that can be used for indoor localization. In this regard, this dissertation targets at improving ...
Konferenzveröffentlichung
Unsymmetrische Beiträge zur Momentanreserve durch Erzeugung, Verbrauch und Speicher
(Conexio-PSE GmbH, 2022)
Im Zuge der Dekarbonisierung müssen Verbundsysteme auf wiederkehrende Situationen vorbereitet werden, während derer sie vor allem aus Wechselrichtern gespeist werden. Der stabilisierende Einfluss der durch Synchrongeneratoren direkt an das Netz gekoppelten Schwungmassen auf jede Frequenzveränderung ist heute unverzichtbar. Die inhärente Sofortreaktion von Synchronmaschinen auf Spannungswinkeländerungen und Frequenzbewegungen heißt Momentanreserve. Wenn sich Verbrauch oder Erzeugung dynamisch ändern, und besonders ...