Inrush Current Effects on SiC-MOSFETs for LLC Converter

2020 ◽  
Vol 1004 ◽  
pp. 1134-1140
Author(s):  
Yoshimasa Takaku ◽  
Hikaru Tanaka ◽  
Yosei Takada ◽  
Shuhei Nakata

We prototyped an LLC converter using SiC-MOSFET and GaN-FET to study the device dependence of the resonant type converter characteristics and high current effects on the devices during the start-up mode.Under steady state operation, no observable difference exists between the SiC-MOSFET and GaN-FET in current and voltage waveforms and energy conversion efficiency is over 96% regardless of the device used.However, significant differences exist during the start-up mode. As for the SiC-MOSFET, the inrush current is at maximum in the first few cycles and gradually decreases to steady state. As for the effects on the device, there are no characteristic changes or current waveform fluctuation during the start-up period even after 50 repetitions.Alternately, in the case of GaN-FET, the maximum inrush current is at the first cycle and decreases rapidly to half only a few cycles later. The multi-pulse experiment shows that a single high current pulse degrades the I-V characteristics of the device and the subsequent pulse current decreases. It is also noted that the degradation could be overcome by a longer interval after the high current, however, no further improvement is seen above a 20 µs interval.

2018 ◽  
Vol 187 ◽  
pp. 01003 ◽  
Author(s):  
H. Braune ◽  
K.J. Brunner ◽  
H.P. Laqua ◽  
S. Marsen ◽  
D. Moseev ◽  
...  

At the stellarator Wendelstein 7-X (W7-X) Electron Cyclotron Resonance Heating (ECRH) is the main heating system for steady-state operation and was the only available heating system during the operation phase OP1.2a in 2017. The ECRH, equipped with 10 operational 140 GHz gyrotrons [1], was used for different tasks at W7-X such as wall conditioning, controlled plasma start-up from the neutral gas up to steady state plasma control and different heating scenarios such as X2-mode and O2-mode heating as well as current drive (ECCD). The operational experiences and improvement opportunities of the ECRH plant will be discussed.


2017 ◽  
Vol 62 (1) ◽  
pp. 145-161 ◽  
Author(s):  
Jerzy Michalczyk ◽  
Łukasz Bednarski ◽  
Marek Gajowy

Abstract The influence of the feed material on steady vibrations as well as on the transient resonance during the start-up and coasting of the suspended screen, was analysed in the hereby paper. The influence of the feed material presence on the possibility of performing the first half-turn of the vibrator was also established. The original, feed material simulation model reflecting its layer properties and diversification of feed particles vibrations along the screen riddle – specially developed for this aim – was applied in investigations.


1994 ◽  
Vol 30 (12) ◽  
pp. 263-273 ◽  
Author(s):  
E. Colleran ◽  
S. Finnegan ◽  
R. B. O'Keeffe

The start-up and steady-state operation of a full-scale fixed bed digester treating citric acid production wastewater with an estimated COD/sulphate ratio of approximately 4 are described. Parallel studies at laboratory-scale with two reactors, one of which received the same high influent sulphate concentration as the full-scale plant, confirmed the finding that methanogenesis was not inhibited by the level of sulphate reduction shown to occur. After long-term operation on a high sulphate influent, the retained biomass in the laboratory and full-scale reactors displayed a very low specific methanogenic activity against propionate and butyrate. Since propionate and butyrate were barely detectable in the effluents at steady-state, their oxidation under high influent sulphate conditions may be completely or incompletely mediated by fatty-acid-utilising SRB.


2010 ◽  
Vol 15 (3) ◽  
pp. 143-149
Author(s):  
Luis A. Flores-Oropeza ◽  
Alejandro Román-Loera ◽  
Jorge E. Macías-Díaz ◽  
Felipe de J. Rizo-Díaz

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