Electrical Vehicles (EVs) have gained popularity in recent years in the automotive field. They are seen as a way to reduce the CO₂ footprint of vehicles. Although EVs have witnessed significant advancement in recent years, they still have two major setbacks: limited autonomy and long recharging time. Dynamic Inductive Power Transfer (DIPT) systems permit charging EVs while driving, provide unlimited autonomy, and eliminate stationary charging time and lower battery dependency. Multiple transmitters are required to achieve DIPT; thus, dealing with transient phases is essential because every time a receiver crosses over from one transmitter to another, it experiences a new transient phase. This article presents a novel control strategy for multi-transmitter DIPT systems that ensures a continuous and stable power transfer to a moving EV. The proposed control strategy eliminates drop and inrush currents during transient phases. The control integrates a soft start feature and a degraded operating mode at a predefined maximum current value. The studied structure is a symmetrical series–series compensation network. Each transmitter coil is driven by a variable frequency inverter (around 85 kHz) to ensure Zero Phase Angle mode. The control strategy was numerically validated using MATLAB Simulink and then tested experimentally. Results show a relatively low power disruption after applying the proposed control during transmitter sequencing.

In this work, ElectroStatic Discharge (ESD) tests are performed on SiC MESFETs in order to understand their physical behavior and failure mechanisms during such stresses. The purpose is to point out advantages and drawbacks of this technology, paying special attention to aspects related to its possible commercialization and reliability. Three MESFETs designed to be integrated as a driver in monlithic SiC systems, featuring some ESD internal protection are investigated. Different configurations on ohmic and Schottky contacts are analyzed. Lock-in thermography is carried out for the physical failure location. With TCAD Sentaurus simulation, it allows to determine the nature of the defects on the damaged areas. Hypothesis on the failure mechanism as SiO2 breakdown or SiC sublimation are presented. Solutions to increase the ESD robustness such as a Zener diode integration or the use of Al2O3 dielectric for passivation are therefore proposed in this article.

Due to the expansion of defects like single Shockley-type Stacking Faults inside the SiC epitaxial drift layer, during high current stress, classical SiC MOSFETs can be victims of the degradation of their electrical characteristics. The introduction of an epitaxial SiC buffer layer between the substrate and the n- drift epilayer, called recombination-enhancing buffer layer, was shown to avoid this degradation. In this paper, TCAD simulations of the electrical behavior of such a commercial SiC MOSFET device with varying buffer layer thickness are studied, indicating only small modifications of the electrical characteristics. These simulations are combined with the characterization of the local electrical properties using an AFM-sMIM technique, allowing to determine the real thickness of the different layers of the device. These measurements highlight an inhomogeneous conductivity in the SiC substrate, being probably compensated by the introduction of the SiC buffer layer.

The application of dynamical inductive power transfer (DIPT) systems is currently seen as one of the possible solutions to improve the autonomy of embedded power devices. In this context, electromagnetic field emissions play a crucial role in the system’s design. In this paper, a new coil topology for magnetic couplers in DIPT systems is proposed, based on the use of adjacent current loops, which can improve the tradeoff between reducing the magnetic field emissions near the magnetic coupler and maintaining almost the same system’s efficiency. To evaluate the topology’s performance, finite element method (FEM) simulations are carried out to determine the impact on the magnetic field emissions and the coupling coefficient, permitting to optimize the coil geometry. Finally, a DIPT system prototype is developed for a transfer power of 500 W, validating the results obtained by modeling.

We investigate here the feasibility of operating a three-phase diode rectifier at cryogenic temperature. To do so, several power diodes are tested at room and LN2 temperatures. Then a 3.4 kW three-phase diode rectifier prototype is built and tested at room and LN2 temperatures. Besides we prove that one can predict the performances of such cryogenic diode rectifier by using only the measured diode I-V characteristics. Finally, we assess the relevance of this technology by comparing a cryogenic diode rectifier with its conventional counterpart. The gain may not be in terms of efficiency if cooling power has to be generated, but in terms of power density, since the heat sink is greatly reduced when considering LN2 operation. This study is of interest for compact and lightweight superconducting conversion chains in various sectors, including wind energy and air transportation.

This paper presents the study of air-core transformers for electric vehicles, developing them for medium-power (tens of kWs) converter applications specifically used at a high frequency. Air-core transformers have the advantage of lacking magnetic saturation and iron losses, making them suitable for high-frequency applications. We designed and manufactured a transformer for a determined frequency and inductance value. The design of this passive component aims to both keep the magnetic field inside the transformer and manage the thermal energy efficiently. The electrical, magnetic, and thermal properties are simulated and then verified by experiments with a specific test bench. The transformer reaches high performances for a higher frequency than usual for an equivalent power transfer in automotive applications.