Ricerc@Sapienza

This study deals with the optimization of a shielding structure composed by multiple active coils for mitigating the magnetic field in an automotive wireless power transfer (WPT) system at 85 kHz. Each active coil is independently powered and the most suitable excitation is obtained by an optimization procedure based on the Gradient Descent algorithm. The proposed procedure is described and applied to shield the magnetic field beside an electric vehicle (EV) equipped with SAE standard coils, during wireless charging.

Feature at a glance: Although a lack of safety features is often reported as the most important factor in tractor accidents, an accident per se is the outcome of many elements, including the amount of attentional control operators exert over the driving task. The lack of active attentional control is sometimes referred as “absentmindedness,” and many studies have investigated this phenomenon as the expression of individual differences.

An active coil system is proposed to shield the magnetic field produced by a dynamic wireless power transfer (WPT) system used to power electric vehicles (EVs) in motion. The considered dynamic WPT is based on an electrified road with many short-track pads. A sophisticated mathematical procedure is developed to optimize the design of the active coils configuration and their excitation.

In this paper it is shown how to obtain a low-cost, high-resolution and fault-robust position sensing system for permanent magnet synchronous motor drives operating in safety-critical systems, by combining high-frequency signal injection with binary Hall-effect sensors. It is shown that the position error signal obtained via high-frequency signal injection can be merged easily into the quantization-harmonic-decoupling vector tracking observer used to process the Hall-effect sensor signals.

This paper presents a closed-loop flux-weakening controller for hybrid-excitation synchronous machine drives based on separate regulation of amplitude and phase angle of the armature voltage. Operating point analysis is carried out to investigate the dynamic properties of the drive and to give guidelines in the tuning of the controller. Finally, experimental tests validating the theoretical derivations are performed on a prototype hybrid-excitation drive.

Il punto cardine del lavoro è la prototipazione e caratterizzazione di metamateriali fonoassorbenti, potenzialmente destinabili ad interventi di correzione acustica in ambito automobilistico, basati su un risonatore di Helmholtz a cavità irregolare implementato con filtri porosi realizzati via 3D printing. Il suddetto sistema si prefigge lo scopo di minimizzare l’annoyance in abitacolo dovuto ad un fenomeno che va sotto il nome di Cavity Noise (CN), scaturente in seguito all’interazione pneumatico-strada.