High Voltage DC Source Research Articles

Designing and Development of 30 KV DC Rectifier Amplifier for Polling Optimization on PVDF Thin Film

DC high voltage amplifier is one of the important components to support of PVDF thin films polling equipment. Hardware polling is a very important tool in the characterization of PVDF thin films to increase piezoelectric properties. The existence of the problem will be difficult to obtain a high voltage DC sources of lead in the market encouraged us to design and create high-voltage DC source. In research that has been done I've been able to design and create high-voltage amplifier 30 KV DC as a producer of high electric field. To validate the performance of this high voltage DC amplifier has created further testing and measuring the output voltage. Testing is performed to determine the precision, accuracy and stability of the output voltage of the amplifier for more than 60 minutes. From the test results and output measurements performed show that the relative error of 4.5%. Tool output stability is good enough for a span of 30 minutes. This indicates that the design and manufacture of high DC voltage gain have been successful. Keywords: DC Amplifier, Electric field, High voltage, Polling, PVDF Film

Three‐phase hybrid multilevel inverter with less power electronic components using space vector modulation

This study presents a new design and implementation of a three-phase hybrid multilevel inverter (MLI) using space vector modulation. The proposed MLI consists of a reduced number of dc sources and switches to minimise the control complexity. The developed topology consists of two stages: main stage and auxiliary stage. The main stage is a conventional three-phase inverter with one high-voltage input dc source and six switches. The auxiliary stages contain three individual cells. Each cell consists of two switches and one low-voltage input dc source. This topology is a modular type and without changing the previous connection it can be extended for more number of output voltage levels by adding certain number of auxiliary stages. A space vector modulation control technique has been utilised in order to generate different switching sequences. The special feature of the proposed system is its capability to maximise the number of voltage levels using a reduced number of isolated dc voltage sources and electronic switches. A prototype has been developed and tested for various modulation indexes to verify the control technique and performance of the topology. Experimental results validate the simulation results and the experimental results show a good similarity with the simulation results.

Research for High-Voltage Nanosecond Rectangular Pulse Generator

In order to calibrate the response characteristic of voltage dividers, the article presents a potable high-voltage nanosecond rectangular pulse generator based on the transmission-line theory. The generator consists of DC high-voltage source, pulse forming line (PFL), special high-voltage switch, pulse transmission line (PTL), resistive load and coaxial voltage divider. The compact charging and discharging circuit is developed coaxially and the interference proof performance is excellent. The voltage amplitude and the pulse width can vary from the output of the DC high-voltage source and the length of PFL respectively. In the article the theory of pulse forming process, the design and the key devices of the generator are investigated theoretically and experimentally. The experimental results demonstrate that the generator can meet the measurement demands and export well-defined rectangular pulses with the rise time less than 751.738ps and the voltage amplitude up to 2kV.

Chemical kinetics of an argon/methane plasma in a hydrogen reforming reactor

We have studied the characteristics of a plasma reactor for the promotion of chemical reactions aimed to hydrogen reforming from gaseous hydrocarbons. A plasma torch-like electrode configuration was powered by a limited current, high voltage DC source. Using as process gas an argon/methane mixture at atmospheric pressure, we have produced an intermittent spark discharge which has been investigated at different operating parameters. Experimental information on the discharge have been used to perform a numerical simulation of the plasma chemical kinetics. The evolution of the gas-phase composition during and after the interaction in the discharge region was calculated under different operating conditions. The results have been used to predict the hydrogen production yield in the experiments and to study the role played by the different discharge parameters in order to determine the optimal interaction between plasma and gas mixture.

Improvement of Corona Charging System for High Speed Electrophotography

For the purpose of improving the speed of the charging process of electrophotography, a new electrode system was investigated. The system consists of a blade electrode and a metal drum coated with a polymer film. The sharp edge of the blade electrode was retained perpendicularly for the drum surface by opening 2 to 6 mm gap. In order to prevent spark discharge, an 8 MΩ resistor was inserted between the blade and a dc high voltage source, and a glow-like discharge was observed in the space between the blade edge and the surface of the polymer film. As the discharge current obtained by the present electrode system was much higher than that obtained by a single wire corona charger, the charging speed attained by the present system was 7.2 times as fast as the case of the corona charging system.

펄스 레이저 애블레이션이 결합된 고전압 방전 플라즈마 장치를 이용한 유전성 질화탄소 박막의 합성

The dielectric carbon nitride thin films were deposited onto Si(100) substrate using a pulsed laser ablation of pure graphite target combined with a high voltage discharge plasma in the presence of a N<TEX>$_2$</TEX> reactive gas. We calculated dielectric constant, <TEX>$\varepsilon$</TEX><TEX>$\_$</TEX>s/, with a capacitance Schering bridge method. We investigated the influence of the laser ablation of graphite target and DC high voltage source for the plasma. The properties of the deposited carbon nitride thin films were influenced by the high voltage source during the film growth. Deposition rate of carbon nitride films were increased drastically with the increase of high voltage source. Infrared absorption clearly shows the existence of C=N bonds and C=N bonds. The carbon nitride thin films were observed crystalline phase confirmed by x-ray diffraction data.

Fast, uniform, and large-scale heat treatment by plasma-based electrons

Heat treatment of steels by electron beams with an energy density ranging from 1 to 10 kW/cm 2 results in a considerable hardness improvement and wear reduction. However, electron beam treatment is a typical line-of-sight process and demands a complicated target manipulation and beam-rastering system. A new method, circumventing the limitations inherent in the scanning electron beam treatment is presented. The workpiece to be treated is immersed into the plasma and surrounded by a negatively biased grid, preventing the penetration of plasma electrons. Further, the workpiece is connected to a positive DC high voltage source of about 20 kV and a capacitor, acting as an energy storage. Changing the grid bias, electrons are extracted from the plasma and accelerated by the positive potential towards the workpiece. During the pulsed electron bombardment, power densities of about 10 kW/cm 2 can be achieved, resulting in a rapid thermal heating and self-quenching, occurring after the electron pulse. Detailed investigations are presented on the response of plasma if electrons are extracted by a large electrode with special emphasis on the processes near the wall and near the control grid.

The deformation behavior of liquid polybutadiene in various electrostatic fields.

The deformation of a viscous liquid polybutadiene (LPB) drop in an electrostatic field was studied. Three types of electrodes, i.e., a thin plate, a single-needle, and a twin-needle electrodes, were employed in connection with a stabilized high voltage DC source. A PTFE-coated aluminum plate (a counter-electrode) was horizontally settled and connected to the above-mentioned electrode via the high voltage source. A drop of LPB was allowed to stand on the PTFE surface of the counter-electrode and one of the three electrodes was placed above the drop. The LPB drop was deformed responding to the magnitude of the electrostatic field and the deformation manner directly reflected the electrode employed. When the drop was placed between a couple of plate electrodes, it merely behaved as an insulator in a capacitor. The use of the single-needle electrode caused a deformation to doughnut-shaped drop. The most complicated deformation behavior was observed for the twin-needle electrode system: If a gap between the needles, d, was longer than the initial diameter of the drop, W0, the drop expanded in the direction perpendicular to the needleto-needle direction. If d was shorter than W0, however, the expansion was more significant in the needle-to-needle direction than in its perpendicular direction. It is concluded that the coulombic forces, which act between charges stored or induced on the drop surface and the PTFE substrate, resulted in the deformation of the LPB drop.