scispace - formally typeset
Search or ask a question

Showing papers on "Marx generator published in 2018"


Journal ArticleDOI
Jiaqi Yan1, Saikang Shen1, Yanan Wang1, Siyu Zhang1, Le Cheng1, Weidong Ding1 
TL;DR: The main advantage of this trigger is the simultaneous combination of the high repetition rate, low jitter, long lifetime, and great simplicity in a compact structure.
Abstract: This paper presents the design and development of a trigger with a high repetition rate, low jitter, and compact structure for the pseudospark switch (PSS), which includes an improved Marx generator based on avalanche transistors and a corona-plasma trigger unit. The generator adopted a novel 3 × 12-stage Marx circuit based on avalanche transistors in which the failure rate of transistors in the first and second stages was significantly reduced by connecting the parallel capacitors compared to the previous similar generator. The reason for the improved performance was also discussed. The main parameters of output pulses were an amplitude of -7 kV, rise time of 6 ns, jitter of 0.2 ns, and repetition rate of 2 kHz. The corona-plasma trigger unit adopted BaTiO3 ceramics with high er as the dielectric and was arranged in the hollow cathode of the PSS. The experiments of triggering a PSS prototype were conducted. The influence of anode voltage and pressure on the trigger delay and jitter was studied, and the minimum trigger jitter achieved <1 ns. This trigger worked for 107 shots at the repetition rate of 2 kHz continuously without obvious performance degradation and any failure of the generator. The main advantage of this trigger is the simultaneous combination of the high repetition rate, low jitter, long lifetime, and great simplicity in a compact structure.

46 citations


Journal ArticleDOI
TL;DR: In this article, the design strategy for a new Marx generator, based on SiC metaloxide-semiconductor field effect transistors (MOSFETs), proposed for Kicker magnet applications, is described.
Abstract: This paper describes the design strategy for a new Marx generator, based on SiC metal–oxide–semiconductor field-effect transistors (MOSFETs), proposed for Kicker magnet applications. As a starting point, the possible replacement of a thyratron tube associated with an existing kicker system, at CERN, is considered. The specifications of the output pulse are: 40-kV, 3.2-kA, 3- $\mu \text{s}$ flat top duration, 30-ns rise- and fall-time, and 1-Hz repetition rate. A theoretical study for a Marx generator topology, using 50 stages, each 800-V stage comprising 24 SiC MOSFETs in parallel, each MOSFET conducting approximately 140-A pulses is considered. In addition, a four-stage prototype has been evaluated, with almost full current and 3 kV, based on the proposed design, in order to assess the technological advantages of such a system and limitations for the scale up. First tests using parallel SiC MOSFETs are described and results discussed in light of the proposed topology and the physical structure of the assembly.

33 citations


Journal ArticleDOI
TL;DR: This study presents a simplified design for a solid state pulsed power modulator (SSPPM) based on a power cell structure that has advantages such as reliability and modularity and includes a capacitor charger that is simple and compact.
Abstract: This study presents a simplified design for a solid state pulsed power modulator (SSPPM) based on a power cell structure. Similar to the Marx generator, the power cell structure has advantages such as reliability and modularity. In addition, the proposed SSPPM includes a capacitor charger that is simple and compact. The operating principle of, and the design considerations taken for, the SSPPM are discussed from a practical viewpoint. Based on a reasonable approximation, simplified design equations are developed for a capacitor charger and a high-voltage pulse-switching part, which are comprised of an LCC resonant converter and a power stage, respectively. Accordingly, detailed design procedures are proposed to develop the SSPPM with the following specifications: 40 kV, 20 A, 300 μ s, 200 Hz, and 50 kW. The experimental results verify the specifications at the rated operating condition with an efficiency of 92.4%, and also confirm reliable arc-protection performance. Finally, the proposed design methodology, which utilizes simplified equations, can be used for designing an SSPPM based on the power cell structure for extensive applications.

27 citations


Journal ArticleDOI
TL;DR: In this article, the authors presented an innovative design, named the "zigzag design", for the optimization of the compactness and of the rise time of a Marx generator using pulse forming network (PFN).
Abstract: Repetitive high-voltage square pulses are of great importance for producing long-pulse electron beams and high-power microwaves. One of possible technologies for the generation of such pulses is a Marx generator using pulse forming network (PFN) stages, often combined with a pulse sharpening technique to reduce the rise time to a few nanoseconds (peaking stage). This paper presents an innovative design, named the “zigzag design,” for the optimization of the compactness and of the rise time of 400-kV–85-ns PFN-Marx. Thanks to this design, the 16 stages of this generator, which delivers an open circuit output voltage of 720 kV, fit in a 650-mm length. For a slightly overmatched load ( $Z_{\mathrm {load}} = 100 ~\Omega$ ), the output voltage reaches 400 kV with a rise time as less as 5 ns. The inductance reduction associated with the innovative zigzag design, which allows this sharp rise time with no need for a peaking stage, is described. The 85-ns plateau duration of the pulse is given by the PFN construction of each stage, which is based on six ceramic capacitors (2.1 nF–45 kV) connected within a strip line. The 16 PFN stages are housed in a 360-mm diameter gas pressurized vessel. Burst mode operation for a duration of 10 s at a pulse repetition frequency of 100 Hz is reported, for a resistive load and for the electron beam diode of a X-band relativistic backward-wave oscillator (BWO). To reach further compactness, the BWO system is integrated on side of the generator vessel and a U-shaped gas pressurized line connects both systems through a compact conical vacuum insulator.

21 citations


Journal ArticleDOI
TL;DR: In this article, a compact all-solid-state pulsed power modulator was designed based on Marx generator and pulse transformer, which is consisted of a six-stage Marx generator using power MOSFETs as switches to generate primary voltage pulses and a pulse transformer through a closed magnetic core to boost and convert the output high-voltage (HV) pulse.
Abstract: In this paper, a compact all-solid-state pulsed power modulator was designed based on Marx generator and pulse transformer. It is consisted of a six-stage Marx generator using power MOSFETs as switches to generate primary voltage pulses and a pulse transformer through a closed magnetic core to boost and convert the polarity of the output high-voltage (HV) pulse. A MOSFET driver circuit based on optical–electrical isolation was designed for controlling the Marx generator. It shows that the output pulse shapes, especially the rising and falling phases, are determined by the design of the pulse transformer such as its leakage inductance, distributed capacitance, magnetization inductance, and step-up ratio. The designed modulator is able to generate HV pulses with amplitude ranging from −35 to 35 kV, repetition frequency up to 10 kHz, minimum pulsewidth 250 ns. Various types of plasma discharges, including air microdischarge for local treatments, plate-to-plate air dielectric-barrier discharge, underwater discharge, are able to be driven with good reproducibility by this compact pulse modulator.

18 citations


Journal ArticleDOI
TL;DR: In this paper, a buck-boost converter-based Marx generator is proposed to generate high-voltage pulses, where a single-phase inverter is employed to supply parallel diode-capacitor units by positive and negative values of the input dc source.
Abstract: In this paper, a new structure of Marx generator (MG) based on buck–boost converter is proposed to generate high-voltage pulses. In this structure, a single-phase inverter is employed to supply parallel diode–capacitor units by positive and negative values of the input dc source ( $\pm V_{\mathrm {in}}$ ). The main contribution of this paper is proposing a new switching strategy, by which a group of capacitors are charged properly. Finally, the charged capacitors are connected in series such that the output voltage is equal to summation of the capacitors’ voltages. Considering specified value of the output voltage, the number of circuit elements in the proposed structure is reduced in comparison with other topologies of unipolar MG. Furthermore, voltage rating of switches and diodes in the proposed topology is lower than that of other unipolar MG structures. Design of the structure ensures that there is no need to connect the switches in series, when the number of stages is increased. To verify the performance of the proposed MG structure, simulation has been carried out in MATLAB/Simulink. Furthermore, a prototype of the proposed structure has been implemented in the lab. The simulation and experimental results confirm the capability of the structure for generating high-voltage pulses.

13 citations


Journal ArticleDOI
TL;DR: To compose BCPFN and Marx, the design and construction of a sample of Marx pulsed generator based on boost converter (BC) pulse-forming networks (BCPFNs) are presented and a new circuit with the minimum number of switches is suggested.
Abstract: This paper presents the design and construction of a sample of Marx pulsed generator based on boost converter (BC) pulse-forming networks (BCPFNs). BCPFN is used instead of the conventional Marx floors for constructing this pulsed generator. BCPFN is carried out by connecting inductors and capacitors in series and parallel modes, respectively, by using solid-state switches, and during this procedure the pulsed generator converts to BC temporarily and increases the voltage of capacitors uniformly to a considerable value. This technique causes an increase in the discharging voltage level to the load that is many times more than its dc voltage source by charging the capacitors to a greater level. In order to take advantage of the benefits of Marx generator and PFN, this paper suggests a new circuit with the minimum number of switches. It means, to compose BCPFN and Marx, we have tried to design the circuit with fewer switches and instead of it we have achieved our desired performance with changing the operating mode in the states of BC, PFN, BCPFN, and BCPFN Marx. The results are simulated with MATLAB software. At the end, the experimental results of the construction of the above-mentioned system at low-power levels are presented, and the topology’s accuracy is proved by comparing them to the results of simulation.

8 citations


Journal ArticleDOI
TL;DR: The experimental results verify the feasibility of the concept of an all-solid-state quasi-square square pulse Marx generator based on an FRSPT and anti-resonance network.
Abstract: A solid-state quasi-square pulse Marx generator has been designed, constructed, and tested in this paper. The spark gap switches of a typical Marx generator have been replaced by a fractional-turn ratio saturable pulse transformer (FRSPT), and a three-section anti-resonance network has taken the role of pulse forming module in this quasi-square Marx generator. For the switches, thyristors are used as the primary switches and the FRSPT is used as the pulse modulating switch. The experimental results show that if the charge voltage is about 1000 V, the output quasi-square pulse has an amplitude of 18.5 kV and a pulse width of 3.15 μs, and the experimental results verify the feasibility of the concept of an all-solid-state quasi-square square pulse Marx generator based on an FRSPT and anti-resonance network.

8 citations


Journal ArticleDOI
TL;DR: In this article, a high-voltage pulse modulator with a step-up pulse transformer and a bipolar Marx generator was proposed to reduce the turns ratio of PT, leakage inductance, and distributed capacitance.
Abstract: This paper puts forward a repetitive high-voltage pulse modulator, consisting of a step-up pulse transformer to decrease the number of needed semiconductor switches, and a bipolar Marx generator to reduce the turns ratio of PT, leakage inductance, and distributed capacitance, and also to improve the pulse shape. An equivalent circuit of the proposed modulator considering parasitic elements is established. Based on the equivalent circuit, circuit operation is analyzed in detail. In order to verify the theory analysis and circuit operation, simulations are conducted. In addition, a laboratory prototype is implemented. The simulations and experimental results of resistive load and dielectric-barrier discharges load turn out matched quite well with the theory analysis, demonstrating that the prototype can operate with a voltage amplitude in the range of 0–25 kV, a repetition rate of 0.1–5-kHz stably.

8 citations


Journal ArticleDOI
TL;DR: Compared to Marx-generator based switched capacitor DC–DC converters, the proposed configuration has a lower number of semiconductor devices, which affects positively the system cost, and reduces the control complexity.

8 citations


Journal ArticleDOI
TL;DR: In this article, an ultracompact multiprimary winding pulsed transformer developed in common by the Universite de Pau and Hi Pulse Company can generate voltage pulses of up to 0.6 MV, with a rise time of less than 270 ns.
Abstract: The generation of high-power electromagnetic waves is one of the major applications in the field of high-intensity pulsed power. The conventional structure of a pulsed power generator contains a primary energy source and a load separated by a power-amplification system. The latter performs time compression of the slow input energy pulse and delivers a high-intensity power output to the load. Usually, either a Marx generator or a Tesla transformer is used as a power amplifier. In the present case, a system termed “module oscillant utilisant une nouvelle architecture” (MOUNA) uses an innovative and very compact resonant pulsed transformer to drive a dipole antenna. This paper describes the ultracompact multiprimary winding pulsed transformer developed in common by the Universite de Pau and Hi Pulse Company that can generate voltage pulses of up to 0.6 MV, with a rise time of less than 270 ns. The transformer design has four primary windings, with two secondary windings in parallel, and a Metglas 2605SA1 amorphous iron magnetic core with an innovative biconic geometry used to optimize the leakage inductance. The overall unit has a weight of 6 kg and a volume of only 3.4 L, and this paper presents in detail its design procedure, with each of the main characteristics being separately analyzed. In particular, simple but accurate analytical calculations of both the leakage inductance and the stray capacitance between the primary and secondary windings are presented and successfully compared with CST-based results. Phenomena such as the core losses and saturation induction are also analyzed. The resonant power-amplifier output characteristics are experimentally studied when attached to a compact capacitive load, coupled to a capacitive voltage probe developed jointly with Loughborough University. Finally, an LTspice-based model of the power amplifier is introduced and its predictions are compared with results obtained from a thorough experimental study.

Journal ArticleDOI
TL;DR: In this paper, the results of the most recent campaigns with tungsten double planar wire arrays (DPWAs) were demonstrated and analyzed, where the successful implosion of W wire arrays on a university-scale LTD MAIZE generator was demonstrated.
Abstract: Wire arrays were widely studied as loads for Z-pinch generators in order to be used for multiple scientific applications. More recently, tungsten double planar wire arrays (DPWAs), which consist of two parallel planes of wires at a distance of a few millimeters, were suggested and tested for indirect drive inertial confinement fusion. Tungsten DPWAs have previously demonstrated the highest (among planar wire arrays) radiation yield (up to 30 kJ), compact size (few millimeters), and strong electron beam production on university-scale high-impedance Marx bank Zebra generator at University of Nevada, Reno. During the last few years, we have reported on the outcome of the experiments with uniform and mixed Al and stainless steel DPWAs on the low-impedance linear transformer driver (LTD) Michigan accelerator for inductive Z-Pinch experiments (MAIZE) generator at University of Michigan. Here, we present the results of the most recent campaigns with tungsten DPWA loads, where the successful implosion of W wire arrays on a university-scale LTD MAIZE generator was demonstrated and analyzed. These implosions were recorded using filtered X-ray diodes, X-ray spectrometers, and pinhole cameras, and a 12-frame optical shadowgraphy system. In particular, tungsten DPWAs with a mass up to $87~\mu \text{g}$ /cm arranged in various configurations were successfully imploded at a peak current of 0.5 MA during ~190–215 ns. The experimentally estimated changes of tungsten DPWA plasma region inductance and total load inductance were correlated qualitatively in time with X-ray bursts. In addition, on shots that demonstrated strong plasma pinching process and Faraday cup signals time were correlated with the appearance of the minimum current-carrying radius of the plasma column. In addition, analysis of soft (4–7 A) and hard (1–2.4 A) line radiation indicate keV M-shell tungsten (W) plasma and the presence of electron beams.

Proceedings ArticleDOI
01 Jun 2018
TL;DR: In this article, a flexible solid-state Marx generator with a DBD plasma reactor was used for ozone generation for environmental applications, and the results showed high ozone yields (up to 80 g/kWh) and that this yield decreases for high plasma energy densities.
Abstract: In this paper we present our preliminary findings on ozone generation for environmental applications using a flexible solid-state Marx generator with a DBD plasma reactor. The flexibility of the Marx generator allows for a parametric study over various parameters, such as voltage amplitude, pulse duration and pulse repetition rate. We measured ozone concentrations and electrically characterized the plasma for all these parameters. From these measurements we obtained energy efficiencies and ozone yields. The results show high ozone yields (up to 80 g/kWh) and that this yield decreases for high plasma energy densities. We also compare the results to a much faster spark-gap switched nanosecond pulse source with 200 picosecond rise time. The nanosecond pulses from this source produces plasma that is twice as energy efficient as the Marx generator with respect to ozone production. However, the advantage of the Marx generator is that it is much more flexible, compact, and above all: solid-state (and therefore has a significantly longer life time).

Journal ArticleDOI
TL;DR: In this paper, a megawatt-range short pulse generator based on the diode step recovery phenomenon and the Marx generator idea is presented, which utilizes both opening and closing switches in one circuit.
Abstract: A megawatt-range short pulse generator based on the diode step recovery phenomenon and the Marx generator idea is presented. This generator utilizes both opening and closing switches in one circuit. The proposed circuit is compact, light, and low cost and is driven by a low-power source. By using a three-stage Marx generator, the output peak power of 0.6 MW was obtained. The dimensions of the generator are 8 cm $\times8$ cm. Experimental measurements of the output pulse characteristics showed a rise time of 100 ns for a 16- $\Omega $ load. The input peak power was 4 W which showed more than 105 times increase in the pulse peak power.

Journal ArticleDOI
TL;DR: The design considerations and the corresponding measurements for a modular pulsed-power source for voltages of up to 120 kV and its validation prior to the generator assembly are presented.
Abstract: A new modular pulsed-power source with fast rise time and step-wise arbitrary output waveform generation is currently under development to drive the Gepulste Elektronenstrahlanlage device investigated at the Institute for Pulsed Power and Microwave Technology (IHM). Acknowledging the complex design procedures necessary to set up a modular pulsed-power source for voltages of up to 120 kV, this paper focuses on the circuit design for a single stage and its validation prior to the generator assembly. Using a semiconductor-based Marx generator topology, the stages are designed to have an output voltage of 1 kV with a pulse current of up to 600 A. When connected to an ohmic load, the measured current rise times are in the order of 46 ns resulting in the current rise rates of up to 10 kA/ $\mu \text{s}$ using the commercial devices. The step-wise arbitrary output waveform is created by generating the switching commands on the stage using a microprocessor and a fast optical synchronization unit. Effective stage shielding is verified by operating the stage in a 100-kV, 2.5-kA electromagnetic interference test bed. This paper presents the design considerations and the corresponding measurements.

Patent
20 Mar 2018
TL;DR: In this article, a nanosecond electromagnetic pulser is used for generating transient electromagnetic pulse signals with adjustable amplitude and variable pulse width (200-2000 ns) at the two ends of the electromagnetic probe at the load end, and then transient electromagnetic pulses with the pulse width and frequency being set values is generated on the probe.
Abstract: The invention discloses a nanosecond electromagnetic pulser used for electromagnetic fault injection, and belongs to the field of electromagnetic fault injection, and the nanosecond electromagnetic pulser is used for generating transient electromagnetic pulse signals. The nanosecond electromagnetic pulser mainly comprises a direct-current power source, a signal generator, an Marx generator, an MOSFET driving circuit and an electromagnetic probe. The direct-current power source supplies power to the Marx generator and the MOSFET driving circuit, the signal generator provides pulse signals for the MOSFET driving circuit, controls on-off of MOSFET, and then the transient electromagnetic pulse with pulse width and frequency being set values is generated on the electromagnetic probe. Voltage pulse signals with adjustable amplitude and variable pulse width (200-2000 ns) can be generated at the two ends of the electromagnetic probe at the load end, and then transient electromagnetic pulse with the pulse width and frequency being set values is generated on the electromagnetic probe. The nanosecond electromagnetic pulser is simple in design principle, low in manufacturing cost and high in circuit stability.

Proceedings ArticleDOI
01 Sep 2018
TL;DR: A column type set of spark gap switches for 12-stage 5 kJ Marx generator repetitively operated with rep-rate of up to 10 pps was designed and constructed in this article.
Abstract: A column type set of spark gap switches for 12-stage 5 kJ Marx generator repetitively operated with rep-rate of up to 10 pps was designed and constructed. The Marx generator design (peak voltage of 600 kV at 50 kV charging) meets the requirements of pulsed power technologies like concrete construction crashing, removing of concrete surface layers, drilling and cutting of stones. The column of Marx switches includes one triggered switch and eleven self-breakdown two-electrode gaps. A long-time of operation of the switches is ensured by intensive gas circulation through the column and its cooling. High stability of dynamic parameters (stable pulsed self-breakdown voltage and a small discharge time delay) is achieved by gas preionization in the spark gaps by additional corona discharges. The results of experimental tests including the measurements of electrodes erosion provide the estimations for electrode lifetime of about 106 pulses.

Proceedings ArticleDOI
16 Apr 2018
TL;DR: In this paper, the authors presented the results of the development of the Marx generator intended to supply an electron accelerator with the electron beam extraction into gas through a foil window, which has air insulation and consists of 4-6 stages, assembled in the form of artificial long lines with the wave impedance of ~4 Ω.
Abstract: The results of the development of the Marx generator intended to supply an electron accelerator with the electron beam extraction into gas through a foil window are presented. The generator has air insulation and consists of 4-6 stages, assembled in the form of artificial long lines with the wave impedance of ~4 Ω. To eliminate reflections, each of the lines is provided with a matched load. Connection of both the stages in series and matched loads to the stages is made by one block of switches. The generator provides obtaining rectangular voltage pulses of up to 130 -140 kV with the duration of 10 μs at the matched load and 5 μs at an arbitrary constant resistive load, respectively. Assembling the stages from two half-length parallel lines, results in possibility to increase the output voltage and current of the generator.

Journal ArticleDOI
TL;DR: This research has developed a PFM with a quasi-squared output waveform based on a simplified 2 LC section circuit, which shows potential to reduce the size of the high power generator system that is based on it.
Abstract: A pulse forming module (PFM) with a multifunction of energy storage and a quasi-squared pulse output is developed to meet the challenge of a compact design and square output waveform in a high-power Marx generator. A simplified pulse forming circuit comprising only 2 parallel connected LC sections, in which every section contains an inductor and a capacitor in series, has been proposed and investigated carefully to obtain a quasi-squared waveform. Influences of inductance values in the circuit on its output waveform to a resistive load are investigated. PFMs are designed and fabricated based on the 2 LC section circuit, in which series folded film capacitors are employed to achieve a high energy density of 0.04 J/cm3 at a charging voltage of 120 kV. The as-designed module can output a quasi-squared waveform with FWHM of about 180 ns and the flattop duration greater than 90 ns. It can work at a repetition rate as high as 50 Hz, while the output waveforms show small differences. This research has developed a PFM with a quasi-squared output waveform based on a simplified 2 LC section circuit, which shows potential to reduce the size of the high power generator system that is based on it.

Patent
Liu Rubing, Lin Qi, Guangce Lian, Chen Yueshi, Li Fei 
19 Oct 2018
TL;DR: In this paper, a programmable array type plasma jet exciter system was described, and the excitation frequency of the plasma jet array can be conveniently adjusted in real time through programmable signals.
Abstract: The invention discloses a programmable array type plasma jet exciter system, and relates to a plasma jet system. The programmable array type plasma jet actuator system includes a direct current powersupply, a programmable high voltage pulse power supply, a drive board, a transformer, a Marx generator, and plasma jet exciters. The direct current power supply outputs direct current for the drive board, the direct current is modulated to high frequency pulse signals, and the pulse signals are converted to high frequency pulse high voltage through a transformer. The pulse high voltage is rectified to high voltage direct current through a high voltage diode and is input into the Marx generator. Capacitors of the Marx generator are connected to the cathodes and anodes of the plasma jet excitersthrough resistors. The positive electrode of the output end of the programmable high voltage pulse power supply is connected to a trigger electrode of one of the plasma jet exciters provided with thetrigger electrode, and the negative electrode of the output end of the programmable high voltage pulse power supply is connected to the cathode of the plasma jet exciter provided with the trigger electrode. The outstanding advantage of the programmable array type plasma jet actuator system is that the excitation frequency of the plasma jet array can be conveniently adjusted in real time through programmable signals. Multiple plasma jet exciters can be excited and multiple plasma jets can be generated at the same time, and so the weight, volume and energy consumption of the system can be effectively reduced when the programmable array type plasma jet actuator system is applied to the aircrafts.

Book ChapterDOI
01 Jan 2018
TL;DR: In this paper, the authors discuss the principles of operation and overall performance of Marx generators and highlight the importance of overvoltages to Marx operation, as well as advanced triggering techniques.
Abstract: The simplest and most widely used high‐voltage impulse generator is the device Erwin Marx introduced in 1925 for testing high‐voltage components and equipment for the emerging power industry. This chapter discusses the principles of operation and overall performance of Marx generators. For instruction, the design formulas for simple Marx generators based on their equivalent circuits are given in considerable detail. A fully erected Marx generator is essentially a capacitive discharge. Thus, the load voltage depends not only on the characteristics of the Marx but also on the characteristics of the load. The chapter highlights some aspects in the discussion of modified Marx configurations. It reviews the importance of overvoltages to Marx operation, as well as advanced triggering techniques. The chapter also discusses various aspects of Marx generators such as electrical insulation, delay time and jitter, and the selection of components.

Journal Article
TL;DR: In this paper, a comparative analysis based on the number of switches used, polarity, number of capacitors required and working for five switched topologies, six switched topology and high voltage source topology has been done.
Abstract: Solid state Bipolar Marx Generator is drawing considerable attention due to the increased use of pulsed electric fields on food processing industry for extraction, medical field for sterilization, biological fields for water treatment, environmental field for control of air pollution. The bipolar pulses reduce the amount of pulse energy required for a specified application compared to unipolar pulse. This paper gives the overview and comparison of the various topologies used for generation of bipolar high voltage pulse. A comparative analysis based on number of switches used, polarity, number of capacitors required and working for five switched topology, six switched topology and high voltage source topology has been done. IGBTs have been recommended for these topologies as it has high power handling capability and less switching losses. The evolution of solid state Bipolar Marx Generator from conventional Marx Generator using spark gaps has been briefed.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a study to evaluate a Marx topology using MOS-gated thyristors capable of high current output and achieved a peak output of 1 kV and 1 kA with a $2~\mu \text{s}$ pulsewidth.
Abstract: In the field of pulsed power, gas switches have been widely used due to their high operating voltages and currents. One example of these gas switches is the thyratron, which is in use for some particle accelerators even today. At the Extreme Energy-Density Research Institute, the Nagaoka University of Technology, Nagaoka, Japan, such devices are in use. In recent times, semiconductor switches have been considered as possible replacements due to their ease of maintenance and control. In general, it is difficult to achieve the same ratings for maximum switching current and voltage of a gas switch with a single semiconductor device, so connecting many in series, parallel, or a different scheme is often applied. We propose a study to evaluate a Marx topology using MOS-gated thyristors capable of high current output. The attractive factors of these semiconductors are the low gate current required for turning ON, a low resistance during the ON-state, a four-stage prototype was built, and it achieved a peak output of 1 kV and 1 kA with a $2~\mu \text{s}$ pulsewidth. To improve the output voltage and current, a ferrite core was implemented as a magnetic switch on every stage; this method has been used before to improve the efficiency of thyristors, however, not combined with circuit topologies like a Marx generator. Adding these magnetic switches increased the efficiency to 89% (from 70%) and allowed an output of 2.2 kV and 2.2 kA without changing the shape of the pulse or the rise time.

Patent
01 Jun 2018
TL;DR: In this article, a Marx generator of a compact structure is presented, which is not only flexible in terms of capacitance selection but also more compact in structure by combining a plurality of small-capacitance capacitors in parallel to form a capacitor with a larger capacitance, thereby adapting to the development needs of miniaturized and compact pulse power systems.
Abstract: The invention discloses a Marx generator of a compact structure. The Marx generator comprises a first capacitor group, a second capacitor group, a third capacitor group, a fourth capacitor group, a fifth capacitor group, a sixth capacitor group, a switching cavity, a first spark gap switch, a second spark gap switch, a third spark gap switch, a charging inductor, and a load resistor. Compared withthe prior art, the Marx generator of the compact structure according to the invention is not only flexible in terms of capacitance selection but also more compact in structure by combining a plurality of small-capacitance capacitors in parallel to form a capacitor with a larger capacitance, thereby adapting to the development needs of miniaturized and compact pulse power systems. The Marx generator of the compact structure in the technical scheme of the invention is reduced in length by five-sixths compared with the existing single-chip single-stage Marx generator, and can easily achieve thecompact structure and miniaturization. In addition, the spark gap switches are arranged in a linear arrangement, the glows generated after the spark discharge are mutually illuminated, and the smoothestablishment of Marx is facilitated.


Patent
09 Oct 2018
TL;DR: In this article, an approximate square wave Marx generator based on a magnetic switch was proposed, which sequentially comprises four parts: a primary discharge unit, a saturable pulsed transformer unit and a Marx generator unit.
Abstract: The invention discloses an approximate square wave Marx generator based on a magnetic switch, which sequentially comprises four parts: a primary discharge unit, a saturable pulsed transformer unit, aMarx generator unit and a discharge unit, wherein a main body part is used for generating an approximate square wave pulse; by adopting the technical scheme of the Marx generator which combines additional regulation capacitance with inverse voltage superposition, output of the square wave pulse is implemented, and by combining a pulse width regulation switch, regulation on a width of the output square wave pulse is implemented A structure and a principle of an existing Marx generator which can generate the approximate square wave pulse are simplified, compactness and a solid state of a hundred-nanosecond order square wave Marx generator are implemented, and the gap of such type of pulse generator at home and abroad is filled up

Proceedings ArticleDOI
03 Jun 2018
TL;DR: In this article, the authors describe three-dimensional particle-in-cell (PIC) simulations of a tunable reflex-triode virtual cathode oscillator (vircator), which is capable of burstmode operation at pulse repetition rates (PRFs) up to 100 Hz for a period of one second.
Abstract: This study serves to describe three-dimensional particle-in-cell (PIC) simulations of a tunable reflex-triode virtual cathode oscillator (vircator). Experimental data from the compact hard-tube reflex-triode vircator developed at Texas Tech University (TTU) is used to validate simulated results. The vircator developed at TTU is capable of burst-mode operation at pulse repetition rates (PRFs) up to 100 Hz for a period of one second. A pulse energy of 158 J drives the vircator, and 600 kV (open circuit) pulse forming network (PFN) based Marx generator. The vircator is comprised of a bimodal, carbon fiber cathode and a pyrolytic graphite anode, with the ability to quickly change the distance between the anode-cathode (A-K) gap, back wall distance, and bottom plate distance between experiments. The PIC simulations have been performed using CST PIC Solver, by Dassault Systemes. The models detail virtual cathode formation and the subsequent extraction of radiated microwave power for a variety of cavity geometries. A working three-dimensional, relativistic, electromagnetic, particle-in-cell model of a vircator allows for quick, pre dictive results relative to building an experimental setup. The model is used to determine the necessary driving voltages, A-K gap distances, and cathode current densities to extract microwave radiation at a desired. Simulated results aid in identifying mode contributions. Voltage, current, and microwave data are presented and compared against experimental results at different operating conditions.

Journal ArticleDOI
TL;DR: In this paper, a new type of Marx generator based on semiconductor switches is designed, which need only one trigger signal which is generated by an avalanche transistor, other switches are triggered by the signals which are generated by voltage dividing capacitive.
Abstract: At present most of the Marx generator based on semiconductor switches not only need generate the same number of trigger signals as the number of switches, but also consider the isolation from output high voltage and driving the signal processing, which makes Marx generator have complex circuits, large volume. In this paper, a new type of Marx generator based on semiconductor switches is designed. This generator need only one trigger signal which is generated by an avalanche transistor, other switches are triggered by the signals which are generated by voltage dividing capacitive. In the PSPICE, a five-stage Marx generator is designed. Choosing a 400V DC voltage source charged, pulse voltage with 1.9KV amplitude and 100ns pulse width is obtained. Finally, a fourstage Marx generator is designed. The charging voltage is 200V and the pulse width of trigger signal is 500ns. A pulse voltage with amplitude 736V and pulse width 562ns is obtained.

Patent
03 Aug 2018
TL;DR: In this article, a lightweight miniature pulse power device, comprising a shell, and a Marx generator body which is integrally mounted in the shell, has been developed through utilization of the single-side lead-out integ-rally packaged double-capacitor PFN modules.
Abstract: The invention discloses a lightweight miniature pulse power device, comprising a shell, and a Marx generator body which is integrally mounted in the shell. The Marx generator body comprises a plurality of single-side lead-out integrally packaged double-capacitor PFN modules, gas spark switches and charging inductors. Two electrode tips are leaded out at the same side of the single-side lead-out integrally packaged double-capacitor PFN modules. The gas spark switches and the charging inductors are closely arranged at one side of the electrode tips. Each gas spark switch is connected between twoadjacent single-side lead-out integrally packaged double-capacitor PFN modules. The gas spark switches are equipped with connection ends connected with the electrode tips, and high voltage input endsconnected with the charging inductors. Electrode ends, the connection ends and the high voltage input ends of the gas spark switches are in an integrated structure. Compared with the existing pulse power device, the pulse power device developed through utilization of the single-side lead-out integrally packaged double-capacitor PFN modules has the advantages that a size and weight can be reducedby more than 50%, the cost is low, the maintenance is simple and convenient and an application range is wide.

Proceedings ArticleDOI
Ming-Xiang Gao1, Yan-zhao Xie1, Yang-Xin Qiu1, Ya-han Hu1, Ke-Jie Li1 
14 May 2018
TL;DR: In this article, the circuit model of the Marx generator involved distributed transmission lines is introduced, which considering the wave process is used to explain the pulse forming process accurately and to optimize the pulser design.
Abstract: The Marx generator is an important device in pulse power technology for generating high voltage pulses. In general, the equivalent circuit of Marx generator circuit is a lumped parameter circuit under the condition of electrically small. However, for a Marx generator generating very short pulses such as ultra-wideband pulses, it is necessary to consider the wave process of pulse forming from the original terminal to the output terminal. In this paper, the circuit model of Marx generator involved distributed transmission lines is introduced, which considering the wave process. The difference between the newly raised Marx generator circuit model and the traditional Marx circuit is demonstrated by simulation and experiment. Based on this circuit model, it is useful to explain the pulse forming process accurately and to optimize the pulser design.