High-stability flat-top pulsed magnetic field, which combines the advantages of pulsed high magnetic field and steady high magnetic field, is an important tool of scientific experiments in the fields of physics, biology, and chemistry. The pulsed generator-rectifier power supply, with controllable output voltage, is commonly used to power multi-coil magnet to generate synthetic flat-top...
Although W-Cu alloy is widely adopted in breakers and spark switches as a kind of anti-ablation material, a series of problems including restrike, flashover, etc. still exist. For spark switches in pulsed power equipment, electrode erosion will cause a lot of problems. Not only the electrode surface, but the insulator surface can also be altered from shot to shot. Therefore, the selection of...
Exploding films have potential applications as fast opening switches, current interrupters, and in the ignition of explosive materials. The exploding film phenomenon is a process in which a high voltage capacitive discharge is passed through a thin layer of metal particles on the surface of a dielectric film. Heat generated from the increase in current forces the aluminum particles from a...
Sulphur hexafluoride (SF6) has traditionally been used as a switching medium within corona-stabilised switches (CSS). Due to its high global warming potential (GWP), however, other gases are under test in order to find a suitable alternative that can be used within CSS, without compromising on switching performance. Design changes may have to be made in order for the switch to remain at the...
In the recent decades, together with power electronics technological advancements, an emerging technology, solid state transformer (SST), has attracted great attention and been extensively investigated for smart grid, while mainly focusing on the research of available and efficient circuit topologies. As the core component of SST, the high frequency power transformer, which replaces the...
Dielectric Elastomer Actuators (DEAs) are a class of electroactive polymers, materials which exhibit a mechanical strain as a response to an electrical stimulus, capable of achieving high actuation strains over 100 %. A key hindrance in the application of DEAs is their need for high voltage in order to actuate, leaving their operating range close to their breakdown range. Therefore, this work...
Nowadays, in pulsed power applications, during the design of a modulator, it is necessary to take into account all problems linked to insulators and their capability to withstand a dielectric strength. Indeed, many of these modulators integrate transformers, allowing a significant increase of voltage. So, the first objective is to provide an adequate insulation to maintain compact size.
This...
Over the past two decades, polymeric nanocomposite materials have been the centre of great attention in the research community. Mixing low concentrations of metal or metal-oxide nanoparticles into polymeric insulators has been shown to improve key characteristics of the material, such as thermal behaviour, mechanical strength and resistance to long-term degradation. Unlike traditional...
Abstract- As Silicon is reaching the theoretical limit, wide bandgap devices such as Gallium Nitride (GaN) transistors are being investigated as replacements for Silicon in high voltage and high temperature applications. To have a better understanding of GaN power devices operating under long term high peak current conditions, GaN devices were switched under the following conditions: high...
The research of nanosecond repetitive pulsed discharges has received extensive attention [1-2]. It is valuable to study on gas discharges under the airflow, as well as flow control, discharge mode, etc. In this paper, we are focus on the discharges under motion law of charged particle of nanosecond pulsed discharges in the vortex flow, applied voltages and repetitive frequencies.
FIG. 1....
With the wide application of power electronic technology in pulsed power supply, high frequency and high voltage transformer has become one of the research hotpots. Magnetic core materials such as Ferrite and Nanocrystalline have excellent high frequency performance. However, they are seldom applied to high power situation by the limits of its manufacturing process. Though Fe-based amorphous...
In order to be able to propose a dual pulse accelerator for future flash X-rays capabilities, a preliminary design of a high current induction injector has been developed. This design is based on the use of dual pulsed power generators actually available in the lab. The architecture, the number of cells needed and the dimensions of the conductors are evaluated with the hypothesis of using...
The 1st radiographic axis of Epure, shared French and British facility, is a linear induction accelerator, a complex system with parts standing out as more critical. Those parts are tested and calibrated on dedicated benches. Two such benches are described here.
The beam evalauation is essential to the right performance of the whole machine. To have good quality assessment of beam relevant...
In this work a description of behavior of ferrite-loaded coaxial lines is carried out by solving the gyromagnetic magnetization equation for the ferrite coupled with the Maxwell equation for transmission line in time domain. The influence of induced radial and axial magnetic field components in the ferrite magnetization is investigated as well the rise time of input high voltage. The model is...
The addition of nanoparticles with conducting and semiconducting properties to liquid and solid insulation systems is a current area of active research interest. In liquid insulation the nanoparticles have been shown to improve the breakdown strength of certain liquids due to their ability to scavenge free electrons from the system. In solid nanocomposites improvements in the physical...
ABSTRACT:A high-current pulse generator of 112.5kJ capacitor bank has been developed for electromagnetic pulse welding. It made up of six paralleled 18.75kJ modules, every module is mainly made up of four paralleled capacitor and a trigger vacuum switch. The high-current pulse generator has been designed and fabricated for maximum operating voltage of 25kV, peak current of 1MA. Using a...
Pseduospark switch, as a kind of low-pressure cold cathode gas switch, has broad application prospects and was studied for more than 30 years. Few researches reported the abnormal discharge in the switch which happened frequently in experiments. In our experiments, different from the hollow cathode discharge, three abnormal discharge modes, cathode sidewall to anode sidewall, cathode sidewall...
Abstract: A new triggered vacuum switch ( TVS) was designed and tested . The TVS was successfully tested up from 500V to 10kV peak charging voltage. Compared to other typical switches, the tested switch showed high reliability of trigger voltage, trigger current. The TVS is used for a high-current pulse generator of 112.5kJ capacitor bank, which has been developed for electromagnetic pulse...
A transmission-line-circuit model of the Z accelerator has been developed to aid in the design and analysis of experiments conducted on Z. The circuit model is based on the Bertha circuit code. Transmission line elements are used to represent Z’s 36 pulse-forming modules, water convolute, vacuum insulator stack, outer magnetically insulated transmission lines (MITLs), vacuum post-hole...