scholarly journals Design of High-Voltage Switch-Mode Power Amplifier Based on Digital-Controlled Hybrid Multilevel Converter

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Yanbin Hou ◽  
Wanrong Sun ◽  
Aifeng Ren ◽  
Shuming Liu
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Prototype System ◽  
Maximum Output ◽  
Multilevel Converter ◽  
Peak Voltage ◽  
Class D Amplifier ◽  
Class D ◽  
Digital Pulse ◽  
Switch Mode

Compared with conventional Class-A, Class-B, and Class-AB amplifiers, Class-D amplifier, also known as switching amplifier, employs pulse width modulation (PWM) technology and solid-state switching devices, capable of achieving much higher efficiency. However, PWM-based switching amplifier is usually designed for low-voltage application, offering a maximum output voltage of several hundred Volts. Therefore, a step-up transformer is indispensably adopted in PWM-based Class-D amplifier to produce high-voltage output. In this paper, a switching amplifier without step-up transformer is developed based on digital pulse step modulation (PSM) and hybrid multilevel converter. Under the control of input signal, cascaded power converters with separate DC sources operate in PSM switch mode to directly generate high-voltage and high-power output. The relevant topological structure, operating principle, and design scheme are introduced. Finally, a prototype system is built, which can provide power up to 1400 Watts and peak voltage up to ±1700 Volts. And the performance, including efficiency, linearity, and distortion, is evaluated by experimental tests.

scholarly journals Novel Enhanced Modular Multilevel Converter for High-Voltage Direct Current Transmission Systems

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2257
Author(s):  
Dimitrios Vozikis ◽  
Fahad Alsokhiry ◽  
Grain Philip Adam ◽  
Yusuf Al-Turki
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Modular Multilevel Converter ◽  
Multilevel Converter ◽  
Medium Voltage ◽  
High Voltage Direct Current ◽  
Current Transmission ◽  
The Cost ◽  
Voltage Harmonics ◽  
Chain Links

This paper proposes an enhanced modular multilevel converter as an alternative to the conventional half-bridge modular multilevel converter that employs a reduced number of medium-voltage cells, with the aim of improving waveforms quality in its AC and DC sides. Each enhanced modular multilevel converter arm consists of high-voltage and low-voltage chain-links. The enhanced modular multilevel converter uses the high-voltage chain-links based on medium-voltage half-bridge cells to synthesize the fundamental voltage using nearest level modulation. Although the low-voltage chain-links filter out the voltage harmonics from the voltage generated by the high-voltage chain-links, which are rough and stepped approximations of the fundamental voltage, the enhanced modular multilevel converter uses the nested multilevel concept to dramatically increase the number of voltage levels per phase compared to half-bridge modular multilevel converter. The aforementioned improvements are achieved at the cost of a small increase in semiconductor losses. Detailed simulations conducted in EMPT-RV and experimental results confirm the validity of the proposed converter.

scholarly journals Implementation and Control of an AC/DC/AC Converter for Double Wound Flywheel Application

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
J. G. Oliveira ◽  
H. Schettino ◽  
V. Gama ◽  
R. Carvalho ◽  
H. Bernhoff
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Experimental Tests ◽  
Prototype System ◽  
Unity Power Factor ◽  
Good Efficiency ◽  
In Series ◽  
Vector Modulation ◽  
Acceleration Mode ◽  
And Control

An all-electric driveline based on a double wound flywheel, connected in series between main energy storage and a wheel motor, is presented. The flywheel works as a power buffer, allowing the battery to deliver optimized power. It also separates electrically the system in two sides, with the battery connected to the low voltage side and the wheel motor connected to the high voltage side. This paper presents the implementation and control of the AC/DC/AC converter, used to connect the flywheel high voltage windings to the wheel motor. The converter general operation and the adopted control strategy are discussed. The implementation of the AC/DC/AC converter has been described from a practical perspective. Results from experimental tests performed in the full-system prototype are presented. The prototype system is running with satisfactory stability during acceleration mode. Good efficiency and unity power factor could be achieved, based on vector control and space vector modulation.

SPS Using SiC Die

2014 ◽  
Vol 617 ◽  
pp. 72-77 ◽  
Author(s):  
Kazuyuki Kakegawa ◽  
Chun Ming Wen ◽  
Naofumi Uekawa ◽  
Takashi Kojima
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
High Voltage ◽  
Output Voltage ◽  
Low Voltage ◽  
Maximum Output ◽  
Compositional Fluctuation ◽  
Good Strength ◽  
Transparent Alumina ◽  
Semiconducting Behavior

Possibility of a use of SiC as SPS die was examined. Although SiC has good strength even at high temperature, electrical conductivity is too low as the SPS die. Maximum output voltage of typical SPS machine is 10 V. Joule heat of SiC by application of 10 V is too small to increase its temperature. One idea to solve this problem in this study is to apply higher voltage to the SiC die. Using prototype high voltage SPS equipment, the temperature of SiC die was successfully elevated. Another idea is to heat the SiC die in advance. SiC has a semiconducting behavior, so that the electrical conductivity at high temperature becomes sufficient for the ordinary SPS equipment. Using SPS machine which has hot-wall, heaters surrounding the die, the temperature of the SiC die was successfully increased by application of low voltage. This SPS had similar sintering effects as the ordinary ones. Partly transparent alumina was successfully prepared. Initial compositional fluctuation of Pb (Zr,Ti)O3was maintained after it was densified by this SiC-SPS.

Low-Voltage Variable Gain Current Amplifier for High-Voltage Signal Processing

2009 ◽  
Vol 129 (8) ◽  
pp. 1511-1517
Author(s):  
Nicodimus Retdian ◽  
Jieting Zhang ◽  
Takahide Sato ◽  
Shigetaka Takagi
Keyword(s):  
Signal Processing ◽  
High Voltage ◽  
Low Voltage ◽  
Current Amplifier ◽  
Variable Gain ◽  
Voltage Signal
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