scholarly journals Precise Electrohydrodynamic Direct-Write Micro-Droplets Based on a Designed Sinusoidal High-Voltage AC Power

Instruments ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 7 ◽  
Author(s):  
Huatan Chen ◽  
Gaofeng Zheng ◽  
Juan Liu ◽  
Jiaxin Jiang ◽  
Guoyi Kang ◽  
...  
Keyword(s):  
High Voltage ◽  
Pulse Width Modulation ◽  
Rapid Development ◽  
Average Diameter ◽  
Input Voltage ◽  
Direct Write ◽  
Direct Writing ◽  
Ac Power ◽  
Voltage Frequency ◽  
Inverter Circuit

The precise manufacturing of micro/nano structures is the key to the rapid development of flexible micro/nano systems. In this paper, a sinusoidal high-voltage alternating current (AC) power is designed for electrohydrodynamic direct-writing (EDW) technology. A push-pull converting circuit is utilized as the direct current (DC) voltage regulator power of a full-bridge inverter circuit. A single-phase full-bridge inverter circuit is used to output the controllable AC voltage, which is then boost-filtered to output the high-voltage sinusoidal AC signal. The amplitude of the output sinusoidal voltage is proportional to the input voltage and the modulation degree of the sinusoidal pulse width modulation (SPWM) inverter circuit. Then, the designed sinusoidal high-voltage AC power is used in the AC EDW process to print micro-droplets. The deposition frequency and the average diameter of droplets can be effectively controlled by adjusting the voltage amplitude and the voltage frequency. The design of this sinusoidal high-voltage AC power will promote research on the applications of EDW technology in the field of micro/nano manufacturing.

scholarly journals COMPARISON OF METHODS FOR COMPENSATION FOR DAMAGE TO H-CELLS IN HIGH-VOLTAGE CASCADE FREQUENCY CONVERTERS

2021 ◽  
Vol 3 (55) ◽  
pp. 24-31
Author(s):  
V. Busher ◽  
◽  
O. Glazeva ◽  
Du Xin ◽  
◽  
...  
Keyword(s):  
High Voltage ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Comparison Of Methods ◽  
Space Vector Pwm ◽  
Space Vector ◽  
Line Voltage ◽  
Third Harmonic ◽  
Frequency Converters ◽  
Voltage Frequency

Purpose. The aim of this work is to find a method of controlling high-voltage frequency converters that would provide the smallest voltage drop on the motor, the least loads and oscillation of electromagnetic torque in an accident modes, and evaluate the effectiveness of pulse width modulation (PWM) methods with the injection of third harmonic and space-vector PWM in emergency modes. Methodology. We have applied the mathematical simulation of the electric drive “High voltage frequency converter with cascaded H-bridges – High power asynchronous machine” in Matlab/SimPowerSystem software for comparison of four PWM types – Sinusoidal PWM (SPWM), Balanced sinusoidal PWM (BSPWM), Balanced PWM with injected third harmonic (THPWM) and Space Vector PWM (SVPWM). Results. The method of balancing the line voltage minimizes shock loads during the transition from normal to emergency mode due to such a shift of the zero point and rotation of the phase vectors, in which the amplitude of the line voltage decreases to the minimum possible value, the spatial position of linear vectors remains unchanged. The conditions of optimal injection of the 3rd harmonic are found, which increases the efficiency of power supply use by 7… 30 % in comparison with symmetric sinusoidal PWM. But in some accidents (6-4-4, 4-3-2, 3-2-2) the 3rd harmonic is not effective. The method of balancing the space vectors provides the same conditions and increases the utilization of power supplies by 15.6 %, regardless of the number of damaged modules, which increases the amplitude of the 1st harmonic in case of accidents by 10 ... 26 % compared with sinusoidal PWM. Comparison of methods of space vector PWM (SVPWM), balancing of phase-to-phase voltage with the injection of the 3rd harmonic (THPWM) with sinusoidal PWM shows that SVPWM is the best method at damage of one or two modules and during normal work of the converter (except for the 3-3-2 configuration), ie in the most common cases. Originality. For the first time, a comparison of all methods of pulse-width modulation in emergency modes and the optimal method for each type of accident for 3-6-stage frequency converters is indicated. Practical value of the work is to provide the necessary mathematical apparatus for calculating signals using BSPWM, THPWM and SVPWM in emergency modes. References 17, table 1, figures 6.

scholarly journals Design of Boost Inverter for Solar Power Based Stand Alone Systems

2019 ◽  
Vol 8 (6S) ◽  
pp. 125-129
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Main Part ◽  
Pulse Width Modulation ◽  
Power Conversion ◽  
Research Work ◽  
Input Voltage ◽  
Voltage Source ◽  
Inverter Circuit ◽  
Conversion Stage

This paper presents a new ideology called as boost inverter which converts input DC supply into AC directly without using any filter circuit. The main part of today’s research work is to use solar energy efficiently. While using for AC autonomous loads, the output from the solar panel should not suffer any losses during the various power conversion stages. The conventional voltage source inverter, which is currently in usage, produces an AC output voltage lower than the DC input supply and thus it requires another power conversion stage. It can be used to drive the loads only after removing the ripples using a filter. The main objective of the project is to produce an AC output voltage higher than the DC input voltage in a single stage. Thus the number of power conversion stages is reduced by using boost inverter circuit. Since Pulse Width Modulation technique is used to drive the circuit, the requirement of a filter at the output is not needed

Power Quality Improvement of High Voltage DC Link using Modified Shunt Active Power Filter

2018 ◽  
Vol 1 (1) ◽  
pp. 54-66
Author(s):  
Rakan Khalil Antar ◽  
Basil Mohammed Saied ◽  
Rafid Ahmed Khalil
Keyword(s):  
Power Quality ◽  
High Voltage ◽  
Pulse Width Modulation ◽  
Active Power Filter ◽  
Active Power ◽  
Voltage Source ◽  
Active Power Filters ◽  
Power Filter ◽  
Power Filters ◽  
Power Quality Improvement

A new control strategy for active power filters is proposed, modeled and implemented in order to improve the power quality of a line commutated converter High voltage DC link. The ability of reactive power and harmonics reductions are generally met by using passive and active power filters. In this paper, modified active power filter with a modified harmonics pulse width modulation algorithm is used to minimize the source harmonics and force the AC supply current to be in the same phase with AC voltage source at both sending and receiving sides of a line commutated converter high voltage DC link. Therefore, it is considered as power factor corrector and harmonics eliminator with random variations in the load current. The modified harmonics pulse width modulation algorithm is applicable for active power filter based on a three-phase five-level and seven-level cascaded H-bridge voltage source inverter. Simulation results show that the suggested modified multilevel active power filters improve total harmonics distortion of both voltage and current with almost unity effective power factor at both AC sides of high voltage DC link. Therefore, modified active power filter is an effective tool for power quality improvement and preferable for line commutated converter high voltage DC link at different load conditions.

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

Electronics ◽  
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.

scholarly journals Hybrid DC-DC Converter with Low Switching Loss, Low Primary Current and Wide Voltage Operation

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2536
Author(s):  
Bor-Ren Lin ◽  
Yi-Kuan Lin
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Input Voltage ◽  
Resonant Circuit ◽  
Switching Loss ◽  
Voltage Range ◽  
Current Loss ◽  
Zero Voltage Switching ◽  
Energy Applications ◽  
Multi Stage

A full-bridge converter with an additional resonant circuit and variable secondary turns is presented and achieved to have soft-switching operation on active devices, wide voltage input operation and low freewheeling current loss. The resonant tank is linked to the lagging-leg of the full bridge pulse-width modulation converter to realize zero-voltage switching (ZVS) characteristic on the power switches. Therefore, the wide ZVS operation can be accomplished in the presented circuit over the whole input voltage range and output load. To overcome the wide voltage variation on renewable energy applications such as DC wind power and solar power conversion, two winding sets are used on the output-side of the proposed converter to obtain the different voltage gains. Therefore, the wide voltage input from 90 to 450 V (Vin,max = 5Vin,min) is implemented in the presented circuit. To further improve the freewheeling current loss issue in the conventional phase-shift pulse-width modulation converter, an auxiliary DC voltage generated from the resonant circuit is adopted to reduce this freewheeling current loss. Compared to the multi-stage DC converters with wide input voltage range operation, the proposed circuit has a low freewheeling current loss, low switching loss and a simple control algorithm. The studied circuit is tested and the experimental results are demonstrated to testify the performance of the resented circuit.

Direct Writing on Paper Substrate to Prepare Silver Electrode Structures for Flexible Sensors

2021 ◽  
Vol 21 (12) ◽  
pp. 6048-6053
Author(s):  
Qi Wang ◽  
Mingwei Li ◽  
Yao Xie ◽  
Yun Ou ◽  
Weiping Zhou
Keyword(s):  
Low Cost ◽  
Rapid Development ◽  
Silver Electrode ◽  
Silver Nanostructures ◽  
Direct Writing ◽  
Paper Substrate ◽  
Electronic Products ◽  
Glass Substrates ◽  
Different Temperatures ◽  
Writing Technology

With the rapid development of the electronics industry, electronic products based on silicon and glass substrates electronic products will gradually be unable to meet the rising demand. Flexibility, environmental protection, and low costs are important for the development of electronic products. In this study, an efficient and low-cost method for preparing silver electrode structures by direct writing on paper has been demonstrated. Based on this method, a flexible paper-based sensor was prepared. The liquid printing ink used mainly comprises a precursor liquid without pre-prepared nanomaterials. The precursor liquid is transparent with good fluidity. Simple direct writing technology was used to write on the paper substrate using the precursor ink. When the direct-writing paper substrate was subsequently heated, silver nanostructures precipitated from the precursor liquid ink onto the paper substrate. The effect of different temperatures on the formation of the silver nanostructures and the influence of different direct writing processes on the structures were studied. Finally, a paper-based flexible sensor was prepared for finger-bending signal detection. The method is simple to operate and low in cost and can be used for the preparation of environment-friendly paper-based devices.

Development of Serial-Connected High Step-Up DC-DC Converter with Single Switch

2013 ◽  
Vol 479-480 ◽  
pp. 535-539
Author(s):  
Van Tsai Liu ◽  
Chien Hao Hsu
Keyword(s):  
Electric Vehicles ◽  
Pulse Width Modulation ◽  
Hybrid Electric Vehicles ◽  
Single Pulse ◽  
Input Voltage ◽  
Duty Ratio ◽  
Leakage Inductance ◽  
High Voltage Gain ◽  
Output Capacitor ◽  
Voltage Spike

In this paper, a novel high step-up DC-DC converter has been designed for fuel cell applications. The proposed high step-up converter can be used for various portable energy storage components such as fuel cells which are used for hybrid electric vehicles (HEV), and light electric vehicles (LEV).The proposed converter is integrated by boost circuit, voltage lift capacitor, and coupled-inductor techniques to achieve high step-up voltage and has several advantages. First, the circuit is controlled by one single pulse width modulation (PWM). Second, the converter consists of active clamp circuit to recycle the leakage inductance and send to output capacitor so that the voltage spike on active switch is suppressed and efficiency is also improved. Third, by using the winding of secondary boost circuit, and voltage lift capacitor techniques, the high voltage gain can be achieved without more than 50% duty ratio, and the slope compensation circuit can also be simplified.Finally, a 1k W prototype converter is implemented, to verify the performance of the proposed converter with input voltage 48V, output voltage 400V, and output power 1k W is also achieved. The highest efficiency is 92.96% at 400W, and the full-load efficiency is up to 90.48%.

Design and Implementation of a New Drive Circuit of Monolithic Emitter-Switching Bipolar Transistor (ESBT)

2014 ◽  
Vol 668-669 ◽  
pp. 812-817
Author(s):  
De Hui Lin ◽  
Ping Lou ◽  
Hui Pin Lin
Keyword(s):  
High Voltage ◽  
Input Voltage ◽  
Bipolar Transistor ◽  
Soft Switch ◽  
Design And Implementation ◽  
Three Phase ◽  
Drive Circuit ◽  
Driving Circuit ◽  
Switch Circuit

This paper introduces a kind of monolithic emitter switched bipolar transistor (ESBT) for three-phase rectifier applications and other high voltage applications. This paper proposes an improved driving circuit, combining the soft switch circuit. We made a flyback circuit prototype which the rated power is 80W, and the maximum input voltage is 800V, and compared with the existing driving circuit.

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