Search results for "Electrical Circuits"
showing 10 items of 91 documents
Optimal Configuration for N-Dimensional Twin Torus Networks
2014
Torus topology is one of the most common topologies used in the current largest supercomputers. Although 3D torus is widely used, recently some supercomputers in the Top500 list have been built using networks with topologies of five or six dimensions. To obtain an nD torus, 2n ports per node are needed. These ports can be offered by a single or several cards per node. In the second case, there are multiple ways of assigning the dimension and direction of the card ports. In a previous work we proposed the 3D Twin (3DT) torus which uses two 4-port cards per node, and obtained the optimal port configuration. This paper extends and generalizes that work in order to obtain the optimal port confi…
Confirmation of the topology of the Wendelstein 7-X magnetic field to better than 1:100,000
2016
Fusion energy research has in the past 40 years focused primarily on the tokamak concept, but recent advances in plasma theory and computational power have led to renewed interest in stellarators. The largest and most sophisticated stellarator in the world, Wendelstein 7-X (W7-X), has just started operation, with the aim to show that the earlier weaknesses of this concept have been addressed successfully, and that the intrinsic advantages of the concept persist, also at plasma parameters approaching those of a future fusion power plant. Here we show the first physics results, obtained before plasma operation: that the carefully tailored topology of nested magnetic surfaces needed for good c…
Experimental Comparative Analysis of Efficiency and THD for a Three-phase Five-level Cascaded H-Bridge Inverter Controlled by Several MC-PWM Schemes
2021
Cascaded H-Bridges Multilevel Inverters are an innovative and promising solution in different application fields. This topology allows obtaining an improvement in the performance (e.g. reduced harmonic content, the low voltage stress on power components, and high efficiency) in respect to the traditional two-level inverters. In this context, the Multicarrier-PWM strategies play an important role thanks to their features. This paper presents an experimental investigation on the performance of a three-phase five-level Cascaded H-Bridge inverter by using different PWM modulation strategies. In particular, the paper is focused on the experimental validation of the main features of Multicarrier …
Video Streaming Distribution in VANETs
2011
Streaming applications will rapidly develop and contribute a significant amount of traffic in the near future. A problem, scarcely addressed so far, is how to distribute video streaming traffic from one source to all nodes in an urban vehicular network. This problem significantly differs from previous work on broadcast and multicast in ad hoc networks because of the highly dynamic topology of vehicular networks and the strict delay requirements of streaming applications. We present a solution for intervehicular communications, called Streaming Urban Video (SUV), that 1) is fully distributed and dynamically adapts to topology changes, and 2) leverages the characteristics of streaming applica…
Performance analysis and comparison of symmetrical and asymmetrical configurations of evanescent mode ridge waveguide filters
2009
[1] In this paper, the trade-offs between out-of-band performance, filter length, power-handling capability, and insertion loss of both symmetrical and asymmetrical evanescent mode ridge rectangular waveguide filters are investigated. As a result, clear design methodologies for optimizing such performances are proposed. The developed methodologies are then applied to design several evanescent mode filters, and a complete performance analysis of the symmetrical and asymmetrical structures is performed. From the performance analysis results, the designer can choose the more appropriate filter topology and design strategy to satisfy the prescribed specifications.
Novel Three-Phase Multilevel Inverter With Reduced Components for Low- and High-Voltage Applications
2021
In this article, a novel multilevel topology for three-phase applications, having three-level and hybrid N -level modular configurations, enabling low-, medium-, and high-voltage operations, is presented. The proposed topology has several attractive features, namely reduced component count, being capacitor-, inductor-, and diode-free, lowering cost, control-complexity, and size, and can operate in a wide range of voltages and powers. Selected simulation and experimental results are presented to verify the performance of the proposed topology. Further, the overall efficiency of the topology and loss distribution in switches are studied. Finally, the key features of the proposed topology in t…
Preliminary test on a cascode switch for high-frequency applications
2020
Nowadays, an increasing electrification level is being addressed towards different sectors, such as transportation and industrial electronics. To bear that, high speed electrical machines represent a mature technology in different application fields, e.g. avionics, automotive, compressors and spindles. In order to guarantee high speed while keeping high power quality without adopting bulky filtering circuits, DC-AC converters shall be controlled by means of high Pulse Width Modulation (PWM) frequencies. In addition to the emerging switching device technologies, such as those based on Silicon-Carbide (SiC) and Gallium-Nitride (GaN), alternative circuital topologies are crucial in order to co…
Optoelectronic Module with Integrated Transceiver and Mux-Demux for Optical Interconnect Applications
2019
The design, development and improvtableement in electronic devices and components have led to the further miniaturization of the system devices and their interconnecting interfaces. Hence, reducing the size of the transmitter (Tx) chips, receiver (Rx) chips and associated components play an important role in designing a reduced/small sized optoelectronic modules for optical interconnect applications. Some of the associated components include multiplexer, demultiplexer, clock and data recovery circuits (CDR), etc. Therefore, in this paper we present an optoelectronic module with integrated transceiver (Tx-Rx) and multiplexer-demultiplexer (mux-demux) with the aim of reducing the total area o…
Output Impedance Improvement Using Coupled Inductors
2017
When using a single DC/DC converter with multiple outputs and having a buck topology, which has one filter inductor per output, the designer can choose to couple these outputs together. This paper demonstrates additional benefits of coupling output inductors together. Apart from saving mass and volume, and due to an improved small signal behaviour it also reduces the output impedance of the regulated output. The paper will analyse a seven output push-pull converter used as a space power converter module and verify the theoretical results with experimental measurements.
Min-Type Control Strategy of a DC-DC Synchronous Boost Converter
2019
International audience; This paper presents the analysis and design of a min-type strategy to control a synchronous boost converter in continuous conduction mode. The strategy uses a nonlinear switching surface to establish the change of topology in the converter and is analyzed by means of a sliding-mode control approach. Subsequently, the min-type strategy is modified by a hybrid control formulation, which introduces a hysteresis width and a dwell-time to obtain a finite switching frequency in the start-up and steady-state respectively. The hybrid control formulation is implemented digitally by means of a microprocessor which processes the samples of inductor current and capacitor voltage…