Development of a 0.6-MV ultracompact magnetic core pulsed transformer for high-power applications

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 Université 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

Temperature dependence of Kerr constant for water at 658 nm and for pulsed intense electric fields

The temperature dependence of the Kerr constant for water has been determined over the range 19 °C-45 °C at a wavelength of 658 nm. This paper presents the experimental arrangement used for this purpose and the data obtained, for which a polynomial fit is provided. A formula is also suggested to help estimate the variation of the Kerr constant for water with both temperature and wavelength

Development of Wideband and Ultra-Wideband High Voltage Pulse Sources in the University of Pau and Their Applications

International audienc

Evaluation of the lightning strike risk applied to particular site located in the French pyrenees

International audienceIn the domain of lightning protection, the vulnerability of structures to lightning is commonly estimated by using the rolling sphere method. This is an electrogeometric model (EGM) and consists in placing over the structure an imaginary sphere of a radius which depends on the estimated peak current of the lightning flash return stroke. In this way all the surface contact points are considered to require protection, whilst the remaining unaffected volume is assumed to be fully protected. In the present work, we propose a novel method allowing the evaluation of the lightning impact probability over a structure. The new approach is applied in the case of the Observatory of the Pic du Midi de Bigorre, in the South of France, where a lightning station is installed. Firstly, an analysis of the lightning characteristics observed at this site is based on existing lightning data. Secondly the new method, based on a 3-D application of the electrogeometric model, is used to provide the probability for each point of the structure to be hit by a downward flash. Finally, the percentage of upward flashes is estimated and coupled with the probabilities for downward flashes to obtain the overall probabilities for the structure

Repetitive Auto-Triggered Marx Generator for an Ultra Wideband Source

International audienc

Design and Construction of High Voltage Modulators to Produce Rectangular Pulses

International audienc

Preliminary Study of Ultra-High Current Thyristors Triggered in Impact Ionization Wave Mode

International audienc

Mobility Drop among Agricultural Parasites Induced by UWB Radiated Fields

International audienc