1,721,222 research outputs found
Gate charge control of high-voltage Silicon-Carbide (SiC) MOSFET in power converter applications
No full textSwitching devices such as Silicon Carbide (SiC) MOSFET present significant performance improvement in high frequency switching power converter applications. This paper presents a gate charge profile investigation of a Silicon Carbide MOSFET and gate driver circuit solutions to optimize both switching speed, power losses and EMI requirements. Main technology issues of Silicon carbide MOSFET are presented in order to understand the correlation between the technology solutions and the switching performances. Driver circuit requirements are highlighted and discussed. A Miller plateau identification method is presented. An independently circuit control principle of drain current and drain-source voltage is presented and discussed. The circuital technique allows a positive impact on the reduction of power losses and electromagnetic interferences leve
Special Issue “Advanced DC-DC Power Converters and Switching Converters”
Full text linkNowadays, power electronics is an enabling technology in the energy conversion development scenario [...
Gallium Nitride Power Devices in Power Electronics Applications: State of Art and Perspectives
Full text linkHigh-electron-mobility transistors based on gallium nitride technology are the most recently developed power electronics devices involved in power electronics applications. This article critically overviews the advantages and drawbacks of these enhanced, wide-bandgap devices compared with the silicon and silicon carbide MOSFETs used in power converters. High-voltage and low-voltage device applications are discussed to indicate the most suitable area of use for these innovative power switches and to provide perspective for the future. A general survey on the applications of gallium nitride technology in DC-DC and DC-AC converters is carried out, considering the improvements and the issues expected for the higher switching transient speed achievable
Chitin, Chitinases and Chitinase-Like Proteins: A Hypothesis on Ancestral Relationships
No full textIn this contribution we reconsider the phylogeny of mammalian proteins homologous to the glycosyl hydrolase 18 family: chitinases and chitinase-like proteins. This problem has been recently dealt with in two important papers (Bussink et al, 2007; Funkhouser and Aronson, 2007). A clear scheme emerges from these analyses, in which chitinase-like proteins are specialized, tissue-specific, mammalian proteins that have lost the chitinolytic function and have acquired a wealth of possible new functions, mainly related to inflammatory processes. We present here preliminary results from different methods of sequence analysis based on: i) multiple alignments; ii) compression algorithms; iii) statistical over(under)-representation of short k-grams. From our preliminary exploration we formulate and discuss the hypothesis that, chitinase-like proteins are the ancestor group, present as pre-chitinase activators in an ancestral unicellular world from which active chitinases originated as a response to the emergence of chitin synthesis. Chitinase-like proteins in mammals could play a role, in inflammation and in cancer development, similar to the ancient role of activator or signalling molecules in unicellular organisms
Frequency Analysis and Comparison of LCCL and CLLC Compensations for Capacitive Wireless Power Transfer
No full textIn this paper a comparison between a LCCL and CLLC resonant compensations for Capacitive Wireless Power Transfer (CWPT) system is presented. A review of several compensation topologies is presented. From this analysis emerges that these two topologies represent the more promising compensation for high power applications, such as Electric Vehicle (EV) wireless charging. The frequency behavior of each topology is analyzed studying the equivalent input impedance and the voltage transfer function. After design of each compensation to operate at optimum operating condition, the output power and the efficiency are evaluated under load, coupling parasitic resistances variations through LTspice simulations
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