A High-Voltage High-Speed AC Switch Based on Controlled Vacuum Surge Arresters

2018 ◽  
Vol 4 (4) ◽  
pp. 4-13
Author(s):  
Vladimir A. SIDOROV ◽  
◽  
Gennady D. DOMASHENKO ◽  
Marat R. AKHMETGAREYEV ◽  
Yurii V. SHCHERBAKOV ◽  
...  
Keyword(s):  
High Voltage ◽  
High Speed ◽  
Surge Arresters

Design Aspects of a High-Speed High-Voltage PMSM for Aerospace Application

2017 ◽  
Vol 10 (3) ◽  
pp. 122
Author(s):  
Flur Ismagilov ◽  
Nikita Uzhegov ◽  
Vyacheslav Vavilov ◽  
Denis Gusakov
Keyword(s):  
High Voltage ◽  
High Speed ◽  
Aerospace Application

scholarly journals The Optimization of Alternating Current Electrospun PA 6 Solutions Using a Visual Analysis System

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2098
Author(s):  
Tomas Kalous ◽  
Pavel Holec ◽  
Jakub Erben ◽  
Martin Bilek ◽  
Ondrej Batka ◽  
...  
Keyword(s):  
High Voltage ◽  
High Speed ◽  
Visual Analysis ◽  
Polyamide 6 ◽  
Alternating Current ◽  
Sine Wave ◽  
Electrospinning Process ◽  
Camera System ◽  
Polymeric Solutions ◽  
Analysis System

The electrospinning process that produces fine nanofibrous materials have a major disadvantage in the area of productivity. However, alternating current (AC) electrospinning might help to solve the problem via the modification of high voltage signal. The aforementioned productivity aspect can be observed via a camera system that focuses on the jet creation area and that measures the average lifespan. The paper describes the optimization of polyamide 6 (PA 6) solutions and demonstrates the change in the behavior of the process following the addition of a minor dose of oxoacid. This addition served to convert the previously unspinnable (using AC) solution to a high-quality electrospinning solution. The visual analysis of the AC electrospinning of polymeric solutions using a high-speed camera and a programmable power source was chosen as the method for the evaluation of the quality of the process. The solutions were exposed to high voltage applying two types of AC signal, i.e., the sine wave and the step change. All the recordings presented in the paper contained two sets of data: firstly, camera recordings that showed the visual expression of electrospinning and, secondly, signal recordings that provided information on the data position in the signal function.

Lightning Protection of Substations and the Effects of the Frequency-Dependent Surge Impedance of Transformers

2013 ◽  
pp. 398-437
Author(s):  
Rafal Tarko ◽  
Wieslaw Nowak
Keyword(s):  
Power Systems ◽  
High Voltage ◽  
Power Transmission ◽  
Electrical Power ◽  
Computer Calculation ◽  
Electrical Power Systems ◽  
Surge Arresters ◽  
Phase Conductors ◽  
Extra High Voltage ◽  
Economic Nature

The reliability of electrical power transmission and distribution depends upon the progress in the insulation coordination, which results both from the improvement of overvoltage protection methods and new constructions of electrical power devices, and from the development of the surge exposures identification, affecting the insulating system. Owing to the technical, exploitation, and economic nature, the overvoltage risk in high and extra high voltage electrical power systems has been rarely investigated, and therefore the theoretical methods of analysis are intensely developed. This especially applies to lightning overvoltages, which are analyzed using mathematical modeling and computer calculation techniques. The chapter is dedicated to the problems of voltage transients generated by lightning overvoltages in high and extra high voltage electrical power systems. Such models of electrical power lines and substations in the conditions of lightning overvoltages enable the analysis of surge risks, being a result of direct lightning strokes to the tower, ground, and phase conductors. Those models also account for the impulse electric strength of the external insulation. On the basis of mathematical models, the results of numerical simulation of overvoltage risk in selected electrical power systems have been presented. Those examples also cover optimization of the surge arresters location in electrical power substations.

4H-SIC Dmosfets for High Frequency Power Switching Applications

2003 ◽  
Vol 764 ◽  
Author(s):  
Sei-Hyung Ryu ◽  
Anant K. Agarwal ◽  
James Richmond ◽  
John W. Palmour
Keyword(s):  
High Voltage ◽  
High Speed ◽  
High Performance ◽  
High Frequency Power ◽  
Power Devices ◽  
Power Switching ◽  
High Speed Switching ◽  
Unipolar Devices ◽  
Very High ◽  
Frequency Power

AbstractVery high critical field, reasonable bulk electron mobility, and high thermal conductivity make 4H-Silicon carbide very attractive for high voltage power devices. These advantages make high performance unipolar switching devices with blocking voltages greater than 1 kV possible in 4H-SiC. Several exploratory devices, such as vertical MOSFETs and JFETs, have been reported in SiC. However, most of the previous works were focused on high voltage aspects of the devices, and the high speed switching aspects of the SiC unipolar devices were largely neglected. In this paper, we report on the static and dynamic characteristics of our 4H-SiC DMOSFETs. A simple model of the on-state characteristics of 4H-SiC DMOSFETs is also presented.

Sign in / Sign up

Export Citation Format

Share Document