scholarly journals Study of the operating modes of the high voltage power source for barrier type discharge excitation

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 46-51
Author(s):  
A. L. Barakhoev ◽  
O. I. Tikhon ◽  
V. V. Tuboltsev
Keyword(s):  
High Voltage ◽  
Atmospheric Pressure ◽  
Output Voltage ◽  
Current Mode ◽  
Voltage Divider ◽  
Power Source ◽  
Operating Frequency ◽  
Switching Frequency ◽  
Lc Circuit ◽  
Barrier Type

The issues related to the features of operation and modes setting of a high-voltage switching power source based on a sequential autonomous resonant inverter with reverse diodes used to excite an atmospheric pressure barrier type discharge are discussed in the article. It is indicated that the characteristic features of the autonomous resonant inverters operation are the occurrence of damped voltage fluctuations in the LC circuit of the inverter, as well as the dependence of the output alternating voltage on the ratio of the inverter operating frequency (thyristor switching frequency) to the natural resonant frequency of the LC circuit. Depending on this ratio, the inverter can operate in discontinuous, boundary and continuous current mode. The amplitude and shape of the inverter output voltage were controlled using a 1:1000 voltage divider with a C1-65A oscilloscope. The shape of the gate trigger pulses was obtained using a C1-167 oscilloscope. It is established that when the gate trigger pulses are asymmetrical relative to each other due to the operation features of the step-up transformers, the value of the alternating high-voltage at the inverter output is insufficient to excite the atmospheric pressure barrier type discharge. In the case of the gate trigger pulses symmetry, the output voltage of the inverter stage reaches the values required for the breakdown of the dielectric medium. Oscillograms of the inverter output voltage while adjusting its operating frequency are obtained. It is shown that the amplitude value of the voltage at the gas-discharge load increases as the operating frequency of the inverter increases. For the gate trigger pulses frequency of 250 Hz the value of the inverter output voltage amplitude was 3.4 kV, for 460 Hz – 4.0 kV, and for 550 Hz – 4.2 kV.

scholarly journals Closed-Form Formulas for Automated Design of SiC-Based Phase-Shifted Full Bridge Converters in Charger Applications

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5380
Author(s):  
Kornel Wolski ◽  
Piotr Grzejszczak ◽  
Marek Szymczak ◽  
Roman Barlik
Keyword(s):  
High Voltage ◽  
High Power ◽  
Output Voltage ◽  
Design Procedure ◽  
Automated Design ◽  
Design Parameters ◽  
Switching Frequency ◽  
Voltage Level ◽  
Voltage Output ◽  
The Impact

Phase-Shifted Full Bridge (PSFB) topology in its four-diode variant is the choice with the lowest part count in applications that demand high power, high voltage, and galvanic isolation, such as in Electric Vehicle (EV) chargers. Even though the topology is prevalent in power electronics applications, no single, unified analytical model has been proposed for the design process of four-diode PSFB converters. As a result, engineers must rely on simulations and empirical results obtained from previously built converters when selecting components to properly match the DC source voltage level with the DC load voltage requirements. In this work, the authors provide a design-oriented analysis approach for obtaining the output voltage and semiconductor current values, ready for implementation in a spreadsheet- or MATLAB-type software to automate design optimization. The proposed formulas account for all the first-order nonlinear dependencies by considering the impact of each of the following eight design parameters: DC-link voltage, load resistance, phase-shift ratio, switching frequency, transformer turns ratio, magnetizing inductance, series inductance, and output inductance. The results are verified through experiments at the power level of 10 kW and the DC-link voltage level of 800 V by using a grid simulator and a SiC-based two-level Active Front End (AFE) with a DC–DC stage based on the PSFB topology. The accuracy of the output voltage formula is determined to be around 99.6% in experiments and 100.0% in simulations. Based on this exact model, an automated design procedure for high-power high-voltage SiC-based PSFB converters is developed. By providing the desired DC-link voltage, output voltage, output power, output current ripple factor, maximum temperatures, and semiconductor and heatsink databases, the algorithm calculates a set of feasible designs and points to the one with the lowest semiconductor losses, dimensions, or cost.

scholarly journals Design buck converter with variable switching frequency by using matlab simulink simulation

2020 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Norazila Binti Md Posdzi ◽  
Norsa’adah Binti Mahmor ◽  
Rasidah Binti Abdul Rani
Keyword(s):  
Output Voltage ◽  
Current Mode ◽  
Buck Converter ◽  
Switching Frequency ◽  
Resistive Load ◽  
Current Waveform ◽  
Matlab Simulink ◽  
Simulink Simulation ◽  
Continuous Current ◽  
Continuous Current Mode

This paper presents the design of a buck converter circuit with different input switching frequency by using Matlab Simulink software. This study focuses on defining the suitable value of the inductor and capacitor to be used in the buck converter with 100VDC supply input, where the input switching frequency is use 5kHz and 25kHz. This is because the input switching frequency of a buck converter affects many aspects of circuit functionality. This design of the circuit used 20% of the duty cycle, and inductor value is 25% of Lmin to ensure the operation is in continuous current mode. The evaluation of inductor current and switching frequency used in the circuit and parameters for this analysis based on the output voltage, inductor voltage and inductor current waveform. The design of the circuit verified by simulation and results compared with the theoretical. In addition, the appropriate input switching frequency between 5kHz and 25kHz has been determined in order to use in the buck converter circuit for 100Ω resistive load.

scholarly journals Slope Compensation Design for a Peak Current-Mode Controlled Boost-Flyback Converter

2018 ◽  
Author(s):  
Juan-Guillermo Muñoz ◽  
Guillermo Gallo ◽  
Fabiola Angulo ◽  
Gustavo Osorio
Keyword(s):  
High Voltage ◽  
High Efficiency ◽  
Power Converters ◽  
Mathematical Expression ◽  
Current Mode ◽  
Input Voltage ◽  
Switching Frequency ◽  
Peak Current ◽  
Flyback Converter ◽  
Coupled Inductors

Power converters with coupled inductors are very promising due to the high efficiency and high voltage gain. Apart from the aforementioned advantages, the boost-flyback converter reduces the voltage stress on the semiconductors. However, to obtain good performance with high voltage gains, the controller must include two control loops (current and voltage), and a compensation ramp. One of the most used control techniques for power converters is the peak current-mode control with compensation ramp. However, in the case of a boost-flyback converter there is no mathematical expression in the literature, to compute the slope of the compensation ramp. In this paper, a formula to compute the slope of the compensation ramp is proposed in such a way that a stable period-1 orbit is obtained. This formula is based on the values of the circuit parameters, such as inductances, capacitances, input voltage, switching frequency and includes some assumptions related to internal resistances, output voltages, and some other electrical properties related with the physical construction of the circuit. The formula is verified numerically using the saltation matrix and experimentally using a test circuit.

scholarly journals Simulation and Steady State Analysis of a Non-isolated Diode Rectifier-fed DC-DC Boost Converter with High Static Voltage Gain

2021 ◽  
Vol 7 (03) ◽  
pp. 20-25
Author(s):  
V. Girija and Dr. D. Mural
Keyword(s):  
Steady State ◽  
Output Voltage ◽  
Current Mode ◽  
Open Loop ◽  
Duty Ratio ◽  
Switching Frequency ◽  
Voltage Gain ◽  
Voltage Profile ◽  
Sinusoidal Input ◽  
Bridge Rectifier

This paper presents the simulation and analysis of a non-isolated step-up DC-DC converter operating in continuous inductor current mode with fixed switching frequency. The proposed converter proves better steady state performance in terms of improved voltage gain compared to the conventional boost configuration. The suggested two stage converter topology is fed by an uncontrolled diode bridge rectifier for which the sinusoidal input AC voltage is (50/ 2 ) V (rms). The design of the converter is such that the input AC voltage of (50/ 2 ) V (rms) is stepped up to around 256 V (DC) at the load end for the duty ratio value of 0.8. The performance of the proposed converter configuration is validated through simulation in Matlab/Simulink platform. The open-loop configuration provides higher constant output voltage profile compared to the conventional boost topology. The output voltage and current profiles show reduced settling time with almost no overshoot. The output voltage ripple is reduced to lower value. The suggested configuration ensures that the voltage-current stress across the switches is also reduced.

scholarly journals Research on Current Backflow of Asymmetric CHB Multi-Level Inverter

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 214
Author(s):  
Manyuan Ye ◽  
Guizhi Song ◽  
Wei Ren ◽  
Qiwen Wei
Keyword(s):  
High Voltage ◽  
Frequency Modulation ◽  
Output Voltage ◽  
Modulation Method ◽  
Switching Frequency ◽  
Double Frequency ◽  
Hybrid Modulation ◽  
Simulation And Experiment ◽  
Multi Level ◽  
The One

For the traditional asymmetric cascaded H-bridge multi-level inverters, the conventional hybrid modulation method has the problem of current backflow in a certain modulation index range. Although the monopolar modulation method effectively solves this problem, the high-voltage unit participates in the high-frequency operation in part of the range, which limits the improvement of the switching frequency of the whole system. The hybrid frequency modulation method can reduce the switching frequency of the high voltage unit to a certain extent, but the harmonic characteristics of the output voltage will be affected. In order to solve the above problems, a double frequency modulation method based on level-shifted PWM (LS-PWM) is proposed. On the one hand, it solves the inherent power back filling problem of the traditional hybrid modulation method, on the other hand, it ensures that the output voltage of the inverter has good harmonic characteristics when the switching frequency of the high voltage unit is low. The results of simulation and experiment prove the correctness of the theoretical analysis.

EMI Noise Reduction of DC-DC Switching Converters with Automatic Output Ripple Cancellation

2020 ◽  
Vol 38 ◽  
pp. 157-170
Author(s):  
Yasunori Kobori ◽  
Yi Fei Sun ◽  
Minh Tri Tran ◽  
Anna Kuwana ◽  
Haruo Kobayashi
Keyword(s):  
Noise Reduction ◽  
Output Voltage ◽  
Current Mode ◽  
Buck Converter ◽  
Operating Frequency ◽  
Switching Converters ◽  
Stable Level ◽  
Voltage Mode ◽  
Voltage Ripple ◽  
Ripple Cancellation

This paper proposes new EMI reduction technologies and automatic output voltage ripple cancellation method for the PWM buck converter with voltage-mode or current-mode and the ripple-controlled converters. Genenrally, modfying the clock frequeny is effective to reduce the EMI noise, but it may increase the output ripple substantially. We have developed techniques to cancel the increased ripple by modifying the slope of the saw-tooth signal or current of the ripple injection circuit. The EMI spectrum of the operating frequency is reduced by more than 15dB and the modified large ripple is canceled to the stable level.

A High-Voltage Terminal for a Field-Emission Gun

1972 ◽  
Vol 30 ◽  
pp. 428-429
Author(s):  
N. F. Ziegler
Keyword(s):  
Field Emission ◽  
High Voltage ◽  
Atmospheric Pressure ◽  
Power Supplies ◽  
High Coherence

A high-voltage terminal has been constructed for housing the various power supplies and metering circuits required by the field-emission gun (described elsewhere in these Proceedings) for the high-coherence microscope. The terminal is cylindrical in shape having a diameter of 14 inches and a length of 24 inches. It is completely enclosed by an aluminum housing filled with Freon-12 gas at essentially atmospheric pressure. The potential of the terminal relative to ground is, of course, equal to the accelerating potential of the microscope, which in the present case, is 150 kilovolts maximum.

100 KV Scanning Microscope

1972 ◽  
Vol 30 ◽  
pp. 472-473 ◽  
Author(s):  
A. V. Crewe ◽  
M. W. Retsky
Keyword(s):  
High Voltage ◽  
Voltage Divider ◽  
Electron Gun ◽  
Objective Lens ◽  
Parallel Beam ◽  
Emission Point ◽  
Error Amplifier ◽  
External Reference ◽  
Scanning Transmission ◽  
Transmission Microscope

A 100 kv scanning transmission microscope has been built. Briefly, the design is as follows: The electron gun consists of a field emission point and a 3 cm Butler gun. The beam has a crossover outside the gun and is collimated by a condenser lens.The parallel beam passes through a defining aperture and is focused by the objective lens onto the specimen. The elastic electrons are detected by two annular detectors, each subtending a different angle, and the unscattered and inelastic electrons are collected by a third detector. The spectrometer that will separate the inelastic and unscattered electrons has not yet been built.The lens current supplies are stable to within one part per million per hour and have been described elsewhere.The high voltage is also stable to 1 ppm/hr. It consists of the raw supply from a 100 kv Spellman power supply controlled by an external reference voltage, high voltage divider, and error amplifier.

scholarly journals Novel High-Efficiency High Step-Up DC–DC Converter with Soft Switching and Low Component Voltage Stress for Photovoltaic System

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1112
Author(s):  
Yu-En Wu ◽  
Jyun-Wei Wang
Keyword(s):  
High Voltage ◽  
Output Voltage ◽  
High Efficiency ◽  
Low Voltage ◽  
Leakage Inductance ◽  
Power Switch ◽  
Half Wave Voltage ◽  
Half Wave ◽  
Voltage Stress ◽  
Voltage Doubler

This study developed a novel, high-efficiency, high step-up DC–DC converter for photovoltaic (PV) systems. The converter can step-up the low output voltage of PV modules to the voltage level of the inverter and is used to feed into the grid. The converter can achieve a high step-up voltage through its architecture consisting of a three-winding coupled inductor common iron core on the low-voltage side and a half-wave voltage doubler circuit on the high-voltage side. The leakage inductance energy generated by the coupling inductor during the conversion process can be recovered by the capacitor on the low-voltage side to reduce the voltage surge on the power switch, which gives the power switch of the circuit a soft-switching effect. In addition, the half-wave voltage doubler circuit on the high-voltage side can recover the leakage inductance energy of the tertiary side and increase the output voltage. The advantages of the circuit are low loss, high efficiency, high conversion ratio, and low component voltage stress. Finally, a 500-W high step-up converter was experimentally tested to verify the feasibility and practicability of the proposed architecture. The results revealed that the highest efficiency of the circuit is 98%.

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