Optical Triggering of 4H-SiC Thyristors with a 365 nm UV LED

Direct light triggering of 4H-SiC thyristors with a 365 nm UV LED was demonstrated. Two different structures with etched and non etched gate were successfully tested. The current rise time was less than 100 ns and the delay time as short as 1.5 μs. The optical energy density necessary to switch-on a thyristor has been studied for different optical power densities and bus voltages. This work shows that the UV LED technology is becoming sufficiently powerful to switch-on SiC thyristors. Thus, an alternative, less expensive and more compact gate light source than UV laser is now possible. This can be of particular interest for very high voltage and pulse power electronic applications.

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High Current (1225A) Optical Triggering of 18-kV 4H-SiC Thyristor in Purely Inductive Load Circuit

Materials Science Forum ◽

10.4028/www.scientific.net/msf.821-823.893 ◽

2015 ◽

Vol 821-823 ◽

pp. 893-896

Author(s):

Sergey Rumyantsev ◽

M. Levinshtein ◽

T. Saxena ◽

Michael Shur ◽

Lin Cheng ◽

...

Keyword(s):

High Voltage ◽

Optical Switch ◽

High Current ◽

Inductive Load ◽

Current Increase ◽

Optical Triggering ◽

Very High ◽

Load Circuit

Optical switch-on of a very high voltage (18-kV class) 4H-SiC thyristor with an amplification step (pilot thyristor) to the current Imax = 1225A has been demonstrated using a purely inductive load. The results obtained show that a further switch-on current increase can only be achieved by introducing additional amplification steps in the pilot thyristor structure.

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New Dielectric Polymer Film Capacitors for Pulse Power Applications

Electronic and Photonic Packaging, Electrical Systems Design and Photonics, and Nanotechnology ◽

10.1115/imece2004-60053 ◽

2004 ◽

Author(s):

M. Zafar A. Munshi ◽

Ayad Ibrahim

Keyword(s):

Dielectric Constant ◽

Energy Density ◽

Frequency Response ◽

High Voltage ◽

Polyvinylidene Fluoride ◽

Dissipation Factor ◽

Pulse Power ◽

Self Healing ◽

Film Capacitor ◽

Very High

High voltage pulse power technologies utilized by the Department of Defense applications such as armor/anti-armor, electromagnetic/electrothermal guns, lasers, high power microwave weapons, etc. are usually satisfied today by film capacitor technologies. Commercial applications extend to a.c. motors, lighting, and automotive and implantable and portable defibrillators, among others. Film capacitors based on polypropylene (PP) and polyester (PET) have the ability to operate at very high voltages and with good reliability. They also offer high breakdown voltages, inherent low losses, excellent frequency response, low dissipation factor (DF), and good self-healing abilities. Unlike most other circuit components, existing capacitor technologies now present a barrier to achieving significant packaging (size and weight) reductions and struggling to meet market-driven performance requirements. The energy density of commercial film capacitors is less than 1 J/cc. Polyvinylidene fluoride (PVDF) has a much higher dielectric constant (12) than commercial films such as polypropylene (PP) (2.5) and a practical energy density of about 2.4 J/cc. However, it has a number of drawbacks including non-linearity of the dielectric constant with voltage, very poor insulation resistance, poor clearing or self-healing ability, poor dissipation factor (DF), higher leakage currents, relatively lower breakdown voltages and is very costly. In recent SBIR Programs, Lithium Power Technologies demonstrated that by combining PP with PVDF in a polymer blend, one could obtain a material with a very high dielectric constant as well as other excellent electrical properties. Electrical data on biaxial oriented thin films and capacitors demonstrated very high breakdown voltages of 700 V/μm to over 1050 V/μm. In contrast, PP films and capacitors resulted in breakdown voltages of 220 to 560 V/±m. Preliminary energy density for the new dielectric capacitor was about 12 J/cc compared to less than 0.5 J/cc for PP. The frequency response data with respect to the DF demonstrated an almost negligible loss in dielectric activity at high frequencies. The new polymer dielectric offers a number of key advantages, including improved performance and lower cost per unit of energy. The technology is a promising candidate for the development of a higher energy density, high voltage metallized film capacitor for a large number of applications including, defense, aerospace, defibrillator, automotive, and electric power generation. This paper will discuss the development of this new technology and commercial potential.

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Improved interfacial chemistry and enhanced high voltage-resistant capability of in-situ polymerized electrolyte for LiNi0.8Co0.15Al0.05O2-Li batteries

Journal of Materials Chemistry A ◽

10.1039/d0ta11170h ◽

2021 ◽

Author(s):

Yue Ma ◽

Qifang Sun ◽

Zhenyu Wang ◽

Su Wang ◽

Ying Zhou ◽

...

Keyword(s):

Energy Density ◽

High Voltage ◽

Lithium Batteries ◽

Interfacial Chemistry ◽

Layered Oxide ◽

Li Batteries

Ni-rich layered oxide LiNi0.8Co0.15Al0.05O2 (NCA) is one of the most promising cathode candidates for higher energy density lithium batteries. However, the extensive application of NCA is hindered due to the...

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Portable DC Supply Based on SiC Power Devices for High-Voltage Marx Generator

Electronics ◽

10.3390/electronics10030313 ◽

2021 ◽

Vol 10 (3) ◽

pp. 313

Author(s):

Jacek Rąbkowski ◽

Andrzej Łasica ◽

Mariusz Zdanowski ◽

Grzegorz Wrona ◽

Jacek Starzyński

Keyword(s):

High Voltage ◽

Specific Area ◽

Input Voltage ◽

Marx Generator ◽

Power Devices ◽

Laboratory Setup ◽

High Voltage Gain ◽

Main Components ◽

Two Stages ◽

Very High

The paper describes major issues related to the design of a portable SiC-based DC supply developed for evaluation of a high-voltage Marx generator. This generator is developed to be a part of an electromagnetic cannon providing very high voltage and current pulses aiming at the destruction of electronics equipment in a specific area. The portable DC supply offers a very high voltage gain: input voltage is 24 V, while the generator requires supply voltages up to 50 kV. Thus, the system contains two stages designed on the basis of SiC power devices operating with frequencies up to 100 kHz. At first, the input voltage is boosted up to 400 V by a non-isolated double-boost converter, and then a resonant DC-DC converter with a special transformer elevates the voltage to the required level. In the paper, the main components of the laboratory setup are presented, and experimental results of the DC supply and whole system are also shown.

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An Accurate Accelerated Steady-State Model For Modular Multilevel Converters With Very High Voltage Levels

2020 IEEE Industry Applications Society Annual Meeting ◽

10.1109/ias44978.2020.9334761 ◽

2020 ◽

Author(s):

Ramadhani Kurniawan Subroto ◽

Yi Chun Chen ◽

Kuo Lung Lian ◽

Chia Chi Chu

Keyword(s):

Steady State ◽

High Voltage ◽

State Model ◽

Multilevel Converters ◽

Steady State Model ◽

Modular Multilevel Converters ◽

Very High

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Common issues in the hetero-epitaxial seeding on SiC substrates in the sublimation growth of AlN crystals

Applied Physics A ◽

10.1007/s00339-021-04770-9 ◽

2021 ◽

Vol 127 (8) ◽

Author(s):

R. Radhakrishnan Sumathi

Keyword(s):

Power Electronic ◽

Etch Pit ◽

Micro Hole ◽

Wet Chemical ◽

The Common ◽

Common Problems ◽

Hole Defects ◽

Sublimation Growth ◽

Impurity Elements ◽

Very High

AbstractAluminium nitride (AlN) is a futuristic material for efficient next-generation high-power electronic and optoelectronic applications. Sublimation growth of AlN single crystals with hetero-epitaxial approach using silicon carbide substrates is one of the two prominent approaches emerged, since the pioneering crystal growth work from 1970s. Many groups working on this hetero-epitaxial seeding have abandoned AlN growth altogether due to lot of persistently encountered problems. In this article, we focus on most of the common problems encountered in this process such as macro- and micro-hole defects, cracks, 3D-nucleation, high dislocation density, and incorporation of unintentional impurity elements due to chemical decomposition of the substrate at very high temperatures. Possible ways to successfully solve some of these issues have been discussed. Other few remaining challenges, namely low-angle grain boundaries and deep UV optical absorption, are also presented in the later part of this work. Particular attention has been devoted in this work on the coloration of the crystals with respect to chemical composition. Wet chemical etching gives etch pit density (EPD) values in the order of 105 cm-2 for yellow-coloured samples, while greenish coloration deteriorates the structural properties with EPD values of at least one order more.

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A high-voltage aqueous lithium ion capacitor with high energy density from an alkaline–neutral electrolyte

Journal of Materials Chemistry A ◽

10.1039/c8ta11735g ◽

2019 ◽

Vol 7 (8) ◽

pp. 4110-4118 ◽

Cited By ~ 20

Author(s):

Chunyang Li ◽

Wenzhuo Wu ◽

Shuaishuai Zhang ◽

Liang He ◽

Yusong Zhu ◽

...

Keyword(s):

Energy Density ◽

High Voltage ◽

Lithium Ion ◽

High Energy ◽

High Energy Density ◽

Carbon Anode ◽

Biomass Carbon ◽

Proof Of Concept ◽

Lithium Ion Capacitor ◽

Neutral Electrolyte

A proof-of-concept lithium ion capacitor comprising LiMn2O4 nanorods as the cathode, a nitrogen-rich biomass carbon anode and a stable alkaline–neutral electrolyte was designed and fabricated.

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