Marx generator

About: Marx generator is a research topic. Over the lifetime, 1276 publications have been published within this topic receiving 8970 citations.

An approach to recover braking energy of a tram

Abstract: This paper describes an approach to recover braking energy of a tram, supplying it back to the overhead lines via the substation DC link. Usually, the trams braking energy is only recovered when another tram is available and demanding energy in the same substation line. Otherwise, the energy is dissipated in a braking resistor contributing to the energetic inefficiency of the system. With the proposed system it is intended to recover the braking energy, which will be stored in capacitive banks. The core bank uses supercapacitors and is basically a Marx generator operating within rated conditions. The system has a second set of capacitors, corresponding to a second stage, and is used when the energy stored is very low and the system cannot provide the rated voltage (720V DC, in this case), at the DC link. With the proposed approach the discharge of these two stages, in order to inject the stored energy in the DC link, is primary made via a DC/DC. Anyway, the system can also provide 230V AC 50 Hz to auxiliary functions, as for instance, powering control and supervision systems, substation lighting, intersections command, dehumidification system, etc., through a DC/AC converter.

The energy and cost calculation for a Marx pulse generator based on input DC voltage, capacitor values and number of stages

Abstract: Visualization of the energy equation can simplify understanding the performance of a Marx pulse generator. In this paper, the energy of a Marx pulse generator is calculated and visualized for input dc voltage from 1 to 20 kV, value of the capacitor from 1 to 33 nF and the number of stages from 1 to 20 stages. Moreover, in order to calculate the approximate cost of the Marx pulse generator, an equation proposed and evaluated.

Development of a 4-MV, 80-kA-Induction Voltage Adder for Flash X-ray Radiography

Abstract: An induction voltage adder (IVA) has been developed to drive rod-pinch diodes (RPDs), to produce X-rays for flash radiography. The IVA facility consists of four-stage induction cavities stacked in series, each of which is single-point driven by a 6- $\Omega $ pulseline. The prime pulsed-power source comprises two Marx generators and four de-ionized water pulselines. Each Marx generator fast charges two pulselines to about 2.2 MV in less than 370 ns. Four electrically triggered, SF6-insulated gas switches serve as energy-transfer switches from pulse-forming lines to output transmission lines, and thus without an additional intermediate energy storage. A stepped inner stalk is utilized to make the vacuum impedance of the secondary transmission line increase from $30~\Omega $ at the first cavity to $120~\Omega $ at the last cavity, to prevent the electron emission from cathode surfaces. The RPD is chosen to create bremsstrahlung X-rays, which are believed to be optimal at voltage levels of about 4 MV. In this article, the design details and experimental results concerning the main components, such as the Marx/PFLs, IVA, and RPD, are demonstrated. The electrical performances of the facility are characterized. Presently, the IVA provides voltages of up to 4.3 MV and currents of up to 85 kA. The X-ray dose is up to 15.5 Rad [lithium fluoride (LiF)] at 1 m with a spot size of 1.4 mm and a FWHM time of 55 ns.

Studies of Implosion and Radiative Properties of Tungsten Planar Wire Arrays on Michigan’s Linear Transformer Driver Pulsed-Power Generator

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.

Compact, DC-powered 100Hz, 600kv pulsed power source

Abstract: A DC-powered, compact source capable of delivering in excess of 300 kV into a matched load is realized driving a 16-stage Marx generator with a 10 kJ/s rapid capacitor charger. The system is capable of delivering 100 J per pulse at a maximum pulse repetition frequency of 100 Hz. The Marx generator and capacitor charger are housed in a cylindrical package with approximate dimensions of 12”X60”. The pair are powered from a 300VDC bus. The unit is controlled remotely via a fiber-optically isolated micro-controller which provides the gate drive signals and user interface for the rapid capacitor charger. Performance data for the Marx generator and the capacitor charger is presented in this paper.