Design and Development of High Efficiency 150 kW Very Compact PLA Core Electromagnetic Coupler for Highly Resonant Power Transfer Technology

Highly Resonant Power Transfer (HRPT) technology is currently receiving very significant attention from the industry and the smart power grid distribution community in particular. This technology ensures electrical power transmission between two points while controlling the level of transmitted power and ensures the immediate shutdown of the transmitted power in the event of a problem. This paper reviews the inductive power transfer method and describes the design of an ultra-compact PLA core electromagnetic coupler. The proposed architecture confines the magnetic field in a toroidal PLA core transformer, and by avoiding the use of heavy and bulky shielding plates, reduces magnetic losses and avoids the Curie point. As a result, the overall unit has a weight of 5 kg and a volume of only 0.013 m3. The electromagnetic coupler is capable of transferring a peak power of 150 kW with an operating frequency of 193 kHz, giving a satisfactory efficiency of 95%. The proposed novel system was first investigated through CST 3D numerical modelling to determine the electrical parameters of the coupler’s equivalent circuit and its efficiency, to verify its compatibility with the ICNIRP 2010 standard and to evaluate its temperature rise with an air-cooling system. Afterwards, the designed coupler was built with a 3D printing device and finally tested experimentally. Simulation and experimental results are compared and show a good agreement.

Feed Signal Influence and Potential Performances of a Compact Radiation Source Based on a Helical Antenna

In the class of emerging high power electromagnetic sources, a complete pulsed power source, named MOUNA (French acronym of “Module Oscillant Utilisant une Nouvelle Architecture”) has been developed. This device must transmit waveforms with a wide frequency band and a high figure-of-merit. To improve the overall performance of the MOUNA system while maintaining its compact size, two approaches are being explored in the paper: the replacement of the dipole antenna by a helical antenna and its feeding signal influence. Helical antenna is cylindrical shape and relatively compact. It offers relatively good gain factor and directivity. The waveform delivered to the antenna is directly related to the amplitude of the radiated electric field. Therefore, different waveforms (step pulse, Gaussian pulse, bipolar pulse and damped sinusoid) are compared to point out the feed signal influence on the radiated electric field. Switch oscillators appear to be considered as interesting resonant sources for driving an antenna. The novel radiating source consists of a primary power source, a resonant transformer, a coaxial transmission line damped oscillator (also termed as coaxial resonator), and a helical antenna. This high voltage pulsed source is very compact (volume of only 2500 cc without the antenna). Our study aims at designing the antenna (number of turns, size…) and a coaxial damped oscillator directly implemented at the output of the transformer. A CST-based simulation is proposed to predict the performances of this wideband source.

A high-power electromagnetic source for disabling improvised explosive devices

Ultra-wideband(UWB)microwave sources driven by specialised pulsed power generators have experienced a considerable development in the last decade due to their wide domain of new applications such as defence or counter-terrorism activity.The authors present the main findings of a research dedicated to the development of a pulsed power-driven electromagnetic field source for disabling improvised explosive devices(IED).The pulsed power generator driving the source is a 13-stage compact Marx producing voltage pulses reaching an amplitude of 0.5 MV,with a pulse repetition frequency(PRF)of up to 100 Hz.The generator is coupled to a bipolar pulse forming line,providing bipolar pulses with a dV/dt of around 1.6 MV/ns.This pulsed power system feeds an array composed of 16 Koshelev-type UWB antennas through an impedance matching transformer.The resulting electromagnetic source is capable to produce pulsed electric fields(PEFs)having a figure-of-merit(FOM)of 1 MV.First,practical experiments were carried out to study the effects of the PEFs on targets.The targets used in the present study are M2B type flashbulbs,known to have the same susceptibility as the US army M6 detonator.Different configurations of wires(shielded,twisted,etc)with different lengths were used in connecting items inside these targets.The tests were performed by placing the flashbulbs at different distances to determine the essential parameters(i.e.,amplitude,duration,and frequency range)of the PEFs required to trigger them.An overview of the experimental campaign and the main findings are also presented followed by conclusions.