Wireless power transfer systems (WPTSs) with inductive coupling are advantageously used to charge the battery pack of electric vehicles. They basically consist of coil coupling, power supply circuitry connected to the transmitting side of the coil coupling, and power-conditioning circuitry connected to the receiving side of the coil coupling. This paper presents the design and implementation of a wireless power transfer (WPT) battery charger for an electric city car. A short overview on the working principles of a series-series resonant WPTS is given before describing in detail the design procedure of the power circuitry needed for its operation, i.e., an alternating-current-direct-current converter cascaded by a high-frequency inverter in the transmitting section and a diode rectifier cascaded by a chopper in the receiving section. The coil coupling with spiral coils is designed with the help of a finite-element-method code. A prototype of the WPT battery charger is built up according to the design results, and experiments that validate the design procedure are carried out.

The expanding Electric vehicle (EV) market is fueled by the need for more efficient and dependable ways to recharge the battery. By eliminating the necessity for direct physical interaction between vehicles and charge equipment, the Wireless Power Transfer (WPT) methodology eliminates the drawbacks and risks associated with the conventional conductive system. The innovative WPT technique replaces the conductive charging system to keep a similar power rating and efficiency. Numerous strategies have been created to improve the effectiveness and dependability of the WPT model. As a result, this review article thoroughly analyses current major research articles that describe WPT technologies for EV charging. The papers are classified based on various coupling types along with magnetic couplers and shielding, compensation, misalignment tolerance and control methods in WPT systems. In addition, the possible research gaps and the challenges associated with the existing works of WPT systems are discussed. The reviewed results are analyzed based on performance metrics and implementation tools attained using above classifications and EMF exposure references employed in the WPT system. The comparative effectiveness is presented in the tables, diagrams, as well as interconnections for ease of presentation and conceptual understanding. The core asset of this article lies in the fact that the findings offer a good "one-stop" resource including both aspects of the system and with regard to the power stage. This review article also emphasizes the potential and obstacles of inductive wireless EV battery chargers. A developer can find this study will contribute substantially to selecting an optimum design for the enhancement of the WPT system.

Vehicle-to-grid (V2G) paradigm is a way of executing services in favor of the grid by electric vehicles (EVs) with bidirectional battery chargers (BBC). The V2G service that has attracted the major interest is the exchange of active power for load leveling purposes. Less attention has received the so-called ancillary V2G services, such as the reactive power compensation. This service is much attractive since it does not involve any exchange of active power and, therefore, leaves the EV batteries charged and does not expose them to additional discharging-charging cycles. The purpose of this paper is to investigate the capabilities of V2G-enabled EVs in executing the reactive power compensation, whether done alone or simultaneously with either battery charging or battery power delivery to the grid. Two topologies of BBC are examined, namely the topologies with the dc side of the charger either directly connected to the battery or through a bidirectional dc-dc converter of buck type. This paper closes by reporting experimental results that corroborate the theoretical findings.

Dynamic wireless charging (DWC) of electric vehicles (EVs) is an emerging technology that could lead to the breakthrough of EVs. The technology is based on the inductive coupling between an electrified track deployed under the road surface and a pickup coil fitted in EV. This paper refers to a lumped track made of DD coils and is concerned with the design of the track layout, namely coil dimension in the motion direction and track coil distance for a given energy requirement. This paper starts by comparing the coupling characteristics of DD coils with different dimensions by a finite-element method (FEM) analysis. Afterward, an analytical procedure is developed to establish the track coil distance able to transfer to a moving EV the propulsion energy required per unit of traveled space. The procedure utilizes the DD-coil coupling characteristics to calculate the power and, from it, the energy transferred from the track coils to the pickup coil along the track. Instrumental in the calculation is the definition of a parameter, denoted as track flux coverage, which gives the ratio between the dimension of the track coils in the motion direction and the coil distance; such a parameter corresponds to the percentage of road populated with track coils so that it is a cost index of the DWC system implementation. Effects of a lateral displacement of the EV motion from the line joining the track coil centers are also analyzed. Design findings are checked against the results obtained with a computer-assisted analysis.

This paper presents two light electric vehicles (LEVs) with a electric propulsion system developed at an academic laboratory. One LEV is an electric city scooter powered by a lithium-ion battery pack and propelled by a wheel motor drive. The other LEV is an electric bicycle powered by a fuel cell system with the assistance of a supercapacitor bank. Power and energy design of the electric propulsion systems of the two LEVs as well as characterization of the energetic devices are illustrated.

Further to the vector analysis in the stationary plane of the behavior of a permanent-magnet brushless dc (PM BLDC) drive, this paper proposes a method of synthesizing the current supply of the motor that ensures torque ripple-free operation of the drive. The synthesis is carried out analytically by the vector approach, and the resulting current vector is then expressed in motor phase coordinates. It comes out that the current vector has a petal-shape trajectory in the stationary plane. The operation of the drive with such a current supply is extensively examined; in particular, the torque capability for an rms value of the phase currents equal to the rated one, the requirements for the voltages to be applied across the motor terminals, and the base speed in correspondence to the supply voltage saturation are determined. At last, experimental traces obtained from an in-wheel PM BLDC drive used for the traction of light electric vehicles are included to corroborate the theoretical findings.