Inst. Energie- und Automatisierungstechnik

125 Items

Recent Submissions
Tag und Nacht: Gibt es Unterschiede der Richtungsabhängigkeit nicht-visueller Effekte?

Broszio, Kai ; Knoop, Martine ; Völker, Stephan (2018-09-10)

Die bisherigen Forschungsergebnisse im Bereich nicht-visueller Wirkungen des Lichts auf den Menschen lassen kein klares Kausalitätsmuster erkennen. Einer der Gründe dafür könnte in der oft unzureichenden Beschreibung der Lichtsituation liegen. Meist wird zur Beschreibung der Intensität des Stimulus die vertikale Beleuchtungsstärke am Auge genutzt. Intrinsisch-photosensitive retinale Ganglienzel...

On the perspectives of SiC MOSFETs in high-frequency and high-power isolated DC/DC converters

Eial Awwad, Abdullah (2018)

Increasing demand for efficiency and power density pushes Si-based devices to some of their inherent material limits, including those related to temperature operation, switching frequency, and blocking voltage. Recently, SiC-based power devices are promising candidates for high-power and high-frequency switching applications. Today, SiC MOSFETs are commercially available from several manufactur...

Control layout of doubly fed induction generator with respect to low voltage ride through for wind energy conversion system

Al-Quteimat, Alaa (2018)

Moving forward, the demand on renewable energy resources is increasing due to their advantages over the fossil fuels, which have harmful effects on the environment. Currently, doubly fed induction generators (DFIG) are widely used for wind turbines. Compared to other variable-speed generators; the main advantage of the DFIG is that the power electronic devices must deal with only about a third ...

Alternating current loss measurement of power cable conductors with large cross sections using electrical methods

Suchantke, René (2018)

High voltage power cables for bulk AC power transport use the Milliken conductor design from a certain cross section up to decrease transmission losses. It is not possible to reliably assess their AC losses by simulation or other calculation methods in advance, as the performance of this complex design strongly depends on manufacturing processes and quality. The exact knowledge of the AC resist...

Enhancing the smoothness of joint motion induced by functional electrical stimulation using co-activation strategies

Ruppel, Mirjana ; Klauer, Christian ; Schauer, Thomas (2017-09-07)

The motor precision of today’s neuroprosthetic devices that use artificial generation of limb motion using Functional Electrical Stimulation (FES) is generally low. We investigate the adoption of natural co-activation strategies as present in antagonistic muscle pairs aiming to improve motor precision produced by FES. In a test in which artificial knee-joint movements were generated, we could i...

In-ear photoplethysmography for central pulse waveform analysis in non-invasive hemodynamic monitoring

Tigges, Timo ; Rockstroh, Jonas ; Pielmuş, Alexandru-Gabriel ; Klum, Michael ; Feldheiser, Aarne ; Hunsicker, Oliver ; Orglmeister, Reinhold (2017)

In recent years, the analysis of the photoplethys-mographic (PPG) pulse waveforms has attracted much research focus. However, the considered signals are primarily recorded at the fingertips, which suffer from reduced peripheral perfusion in situations like hypovolemia or sepsis, rendering waveform analysis infeasible. The ear canal is not affected by cardiovascular centralization and could thus...

Correlation of arterial blood pressure to synchronous piezo, impedance and photoplethysmographic signal features

Pielmuş, Alexandru-Gabriel ; Osterland, Dennis ; Klum, Michael ; Tigges, Timo ; Feldheiser, Aarne ; Hunsicker, Oliver ; Orglmeister, Reinhold (2017)

In this paper we investigate which pulse wave pick-up technologies are well suited for blood pressure trend estimation. We use custom built hardware to acquire electrocardiographic, applanation-tonometric, photo- and impedance-plethysmographic signals during low intensity workouts. Beat-to-beat features and pulse wave runtimes are correlated to the reference arterial blood pressure. Temporal la...

Spatial sampling of a driver’s visual field: characterising peripheral adaptation

Winter, Jan-Christoph (2018)

For the application of the recommended system of mesopic photometry of the Commission Internationale d'Eclairage (CIE) in road lighting design it is necessary to estimate the peripheral state of adaptation of a driver in an urban environment after dark. Estimating the state of adaptation of a driver in the natural setting is not straightforward, because the visual scene is likely complex and i...

Stability, voltage performance and power sharing issues of inverter-based microgrids via LMI optimization

Truong, Duc Trung (2018)

Numerous small distributed energy resources (DERs) form a new generation of power systems - the microgrid. In general, a microgrid stands for a cluster of DERs, which can collectively operate as an individual low-voltage power system during islanded mode. A microgrid can also be operated in connected mode with a large power system. DERs are often interfaced to a microgrid through power electron...

Effective radiant flux for non-image forming effects – is the illuminance and the melanopic irradiance at the eye really the right measure?

Broszio, Kai ; Knoop, Martine ; Niedling, Mathias ; Völker, Stephan (2017-09-18)

Research indicates that intrinsically photosensitive retinal Ganglion Cells are not evenly distributed or evenly sensitive throughout the retina. Still, most research looking into non-image forming (NIF) effects uses an integral measured quantity, illuminance or melanopic weighted irradiance, to represent the amount of light at the participants’ eye level. This paper describes a theoretical app...

Nicht-visuelle Beleuchtung: Reichen integrale Messgrößen aus?

Broszio, Kai ; Niedling, Mathias ; Knoop, Martine ; Völker, Stephan (2017-09-09)

Nicht-visuelle Effekte von Licht und deren Anwendung z. B. im Rahmen von Human Centric Lighting werden in der Lichttechnik zunehmend wichtig. Bereits seit langem bestehen Hinweise auf die Beeinflussbarkeit des circadianen Rhythmus durch Licht. Aber erst seit Entdeckung der retinalen photosensitiven Ganglienzellen (ipRGC) wurde es möglich, ihre Empfindlichkeitsfunktion und ihren Einfluss auf die...

Design, control and analysis of a novel multilevel converter with a reduced switch count

Norambuena, Margarita (2018)

Multilevel converters are used in a wide range of applications, such as drives, energy conversion and distributed generation. This Thesis proposes a new multilevel converter topology that allows increasing the number of output voltage levels with a fewer required power semiconductors than in standard multilevel topologies such as Active Neutral Point Clamped (ANPC), Flying Capacitor Converter (...

The effect of assuming static or dynamic gaze behaviour on the estimated background luminance of drivers

Winter, Jan ; Fotios, Steve ; Völker, Stephan (2018-02-15)

Application of the Commission Internationale de l’Eclairage system for mesopic photometry requires that an estimate is made of the observers’ state of luminance adaptation. This paper addresses an assumption made when estimating background luminance, a component of adaptation luminance. Specifically, using spatial sampling of the visual field we compare background luminances determined from ass...

Gaze direction when driving after dark on main and residential roads: Where is the dominant location?

Winter, Jan ; Fotios, Steve ; Völker, Stephan (2016-02-17)

CIE JTC-1 has requested data regarding the size and shape of the distribution of drivers’ eye movement in order to characterise their visual adaptation. This article reports the eye movement of drivers along two routes in Berlin after dark, a main road and a residential street, captured using eye tracking. It was found that viewing behaviour differed between the two types of road. On the main r...

Enabling continuous blood pressure estimation on artifact contaminated recordings applying a novel pulse wave signal quality detector

Pflugradt, Maik (2018)

The universe of home-monitoring and unobtrusive longtime measurements has experienced a remarkable development in the past years. Smart and cheap recording devices interconnected to body sensor networks have emerged in a great variety, promoting features such as on-line signal processing, low power consumption and high data rates. These hardware systems provide a novel platform for ambitious me...

Synchronous data acquisition with wireless sensor networks

Funck, Jürgen Helmut (2018)

Wireless sensor networks (WSN) are predicted to play a key role in future technological developments like the internet of things. Already they are beginning to be used in many applications not only in the scientific and industrial domains. One of the biggest challenges, when using WSN, is to fuse and evaluate data from different sensor nodes. Synchronizing the data acquisition of the nodes is a...

Untersuchung von Einflussfaktoren auf die Offline- und Online-Kalibration von Teilentladungsmessungen an Hochspannungsbetriebsmitteln

Seifert, Stefan (2018)

Die vorliegende Arbeit behandelt die Untersuchung von Einflussfaktoren auf die Offline- und Online-Kalibration von Teilentladungsmessungen an Hochspannungsbetriebsmitteln, um Fehler bei der Kalibration von Teilentladungsmessungen zu vermeiden und somit verlässliche Ladungspegel im Hoch- und Höchstspannungsbereich zu erhalten. Für die Kalibrierung von Teilentladungsmessungen geht die IEC 60270 v...

Operational planning, modeling and control of virtual power plants with electric vehicles

Raab, Andreas Franz Alois (2018)

The paradigm shift towards a more sustainable energy supply with a less detrimental environmental impact successively changes the energy sector from a polycentric towards a more distributed energy system. The presence of distributed and renewable energy sources combined with the anticipated electrification of the transport sector results in changes along the entire value chain. This so-called t...

Amplifier design for EMG recording from stimulation electrodes during functional electrical stimulation leg cycling ergometry

Shalaby, Raafat ; Schauer, Thomas ; Liedecke, Wolfgang ; Raisch, Jörg (2011)

Functional electrical stimulation leg cycle ergometry (FESLCE), which is often used as exercise for people with spinal cord injury (SCI), has recently been applied in the motor rehabilitation of stroke patients. Recently completed studies show controversial results, but with a tendency to positive training effects. Current technology is identical to that used in FES-LCE for SCI, whereas the pat...

Recent advances in modeling and analysis of bioelectric and biomagnetic sources

Sander, Tilmann H. ; Knösche, Thomas R. ; Schlögl, Alois ; Kohl, Florian ; Wolters, Carsten H. ; Haueisen, Jens ; Trahms, Lutz (2010)

Determining the centers of electrical activity in the human body and the connectivity between different centers of activity in the brain is an active area of research. To understand brain function and the nature of cardiovascular diseases requires sophisticated methods applicable to non-invasively measured bioelectric and biomagnetic data. As it is difficult to solve for all unknown parameters ...