Search results for "Single"
showing 10 items of 4920 documents
Decoupled control scheme of the grid-connected split-source inverter for renewable energy sources
2016
Grid-connected power conversion systems for renewable energy sources must fulfill several requirements, including high efficiency, reduced cost and complexity, and, quite often, also boost capabilities from the dc sources to the ac power grid. For such applications, single-stage power converters with boost capabilities offer some potential advantages. Among several proposed options, split-source inverter (SSI) has been recently investigated. This paper proposes a decoupled control scheme for the SSIs, where the common mode term of the ac modulation signals is used to control the dc input current. Thus, the dc input current and ac output current can be controlled independently. The proposed …
Memory irradiation measurements for the European SMART-1 spacecraft
2005
Three different types of memory circuits, that are intended to be used on board of the European satellite SMART-1, have been radiation hardness tested according to ESA's specification. Since the satellite is equipped with an electric propulsion engine, the spacecraft will be exposed to radiation during a long time when passing the radiation belt of the Earth. A standard DRAM circuit from SAMSUNG will serve as building block of the mass memory of SMART-1, and has been tested for total dose and proton induced single event upset (SEU). The DRAM memory showed surprisingly good resistance against radiation. The proton SEU cross sections for the radiation tolerant SRAM and FIFO circuits have also…
On the effects of HV/MV stations on global grounding systems
2016
The METERGLOB project has faced the issue of the identification of Global Grounding Systems. One of the main point of the problem is to define if an interconnection of single grounding systems gives place to a Global Grounding System in any condition and for every kind of ground fault. This paper focuses the attention on what happens in the case of single line to ground fault inside a HV/MV station whose ground electrode is connected to the cable' shields of the MV lines outgoing the station and supplying the secondary substations of a given area.
A Flux and Speed Observer for Sensorless SPIM Applications
2010
It is usual to find single-phase induction motor (SPIM) in several house, office, shopping, farm, and industry appliances, which is become more sophisticated and requires the development of high performance alternatives to drive a SPIM. All proposed strategies to improve the performance SPIM need the evaluation of the rotational speed or position information. Since the use of conventional sensors to measure the rotational speed cannot be justified for SPIM applications, the adoption of a sensorless strategy is a more reasonable option for these cases. This paper presents a flux and speed observer for sensorless applications involving SPIMs. The performance of the proposed observer is verifi…
Combined Analysis of OFDM-UWB Transmission in Hybrid Wireless-Optical Access Networks
2009
[EN] The hybrid wireless-optical transmission of ultra-wideband signals employing orthogonal frequency-division multiplexing modulation (OFDM) ultra-wideband (UWB) as defined in the ECMA-368 standard is experimentally analyzed in this letter. The OFDM-UWB signals provide 400 Mb/s per user at optical distances from 5 to 50 km on standard single-mode fiber (SSMF). The analysis includes the wireless radiation from 0 to 3 m after optical transmission. The results indicate a maximum error-vector-magnitude degradation of 2.5 dB measured at 1.5-m radio after 50-km SSMF optical transmission for the first two UWB channels. This degradation translates to 1-m maximum wireless-reach penalty.
Heavy ion SEE test of 2 Gbit DDR3 SDRAM
2011
New generation 2 Gbit DDR3 SDRAMs from Micron, Samsung and Nanya have been tested under heavy ions. SEFIs significantly outweigh random SEU errors even at low LET; however, SEFIs can be mitigated by frequent re-initialization.
Journeys from quantum optics to quantum technology
2017
Sir Peter Knight is a pioneer in quantum optics which has now grown to an important branch of modern physics to study the foundations and applications of quantum physics. He is leading an effort to develop new technologies from quantum mechanics. In this collection of essays, we recall the time we were working with him as a postdoc or a PhD student and look at how the time with him has influenced our research.
Enhanced LMMSE equalizer for high-speed single frequency network in HSDPA
2011
Currently, considerable interest has been shown in the research and standardization communities in multicell transmission schemes for HSPA, with a number of possible schemes under discussion that include Multiflow, Fast Cell Switching (FCS) and High-Speed Single Frequency Network (HS-SFN). In particular, HS-SFN is a promising technique that not only combines received energy from participating cells, but also reduces intercell interference with low UE complexity. In principle, HS-SFN can be implemented with a small modification to an LMMSE receiver at the UE. This paper introduces a more advanced LMMSE equalizer for High-Speed Single Frequency Network in HSDPA that achieves further performan…
Automated single ring infiltrometer with a low-cost microcontroller circuit
2015
Automation of a new single ring infiltrometer.Data acquisition system based on the open source microcontroller platform Arduino.New method to minimize the disturbance of the soil surface.New approach to process transducer output. A method to automate data collection with a compact infiltrometer under constant head conditions was developed. The infiltrometer consists of a containment ring with a small quasi-constant head of water (i.e., 2-3mm) that is controlled by a Mariotte reservoir and a data acquisition system based on the open source microcontroller platform Arduino and a differential pressure transducer. The presented design can be easily reproduced and operated.The infiltrometer was …
Shape and dimensional accuracy in Single Point Incremental Forming: State of the art and future trends
2007
Abstract The paper is aimed to discuss some relevant issues concerning an innovative sheet metal forming technology, namely Single Point Incremental Forming. The advantages of this technology are addressed, including its capability to provide effective answers to some impellent industrial requirements: process flexibility, strong customer orientation, production of highly differentiated goods at low industrial costs. As well some relevant drawbacks are highlighted, mainly as concerns the level of accuracy permitted by the process. A wide recognition of the research efforts in this field is presented, taking into account some general considerations on the difference sources of shape and dime…