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.

The advancements in the charging strategy of electric vehicles will have inevitable effects on the electrical grid in the coming future. Electric vehicle battery chargers are able to perform the bidirectional power transfer according to the vehicle-to-grid concept and will offer valuable services to the distribution grid or to the domestic grid of the vehicle owner. The wireless power transfer battery chargers offer the opportunity for a more safe and user-friendly approach to electric vehicles for people who are not confident with technological apparatuses. Bidirectional wireless power transfer chargers capable of vehicle to grid services are the natural evolution of the above-mentioned concepts. This paper faces the topic of developing the control algorithms for such a battery charger, focusing on the needs of the power conversion stages involved in the functioning of a charger enabled for vehicle to home operation. At first, the separation of the control algorithms into two levels is explained, and then the interaction between the algorithms of the internal and external level is introduced. It was decided to design controllers as simple as possible in implementing the control algorithms. This has made it possible to adopt techniques well known in the scientific community for their design and to contain the computational resources necessary for their implementation. Despite the simplicity of the controllers, the introduction and management of the interactions between the various algorithms has made it possible to develop an overall control strategy that at the same time respects the voltage and current limits set by the grid and the battery and also avoids exceeding the maximum operating conditions of the static converters that constitute the system. The algorithms and the relevant controllers are developed one by one in the continuous time domain, using techniques based on the analysis of Bode diagrams of the transfer functions involved in the operation of the system. In designing the controllers, the effects of their subsequent implementation in a discrete time domain are considered together with the effect of the transmission delay originated by the data exchange between the two sections of the system. The discretization of the controllers has been performed using the Tustin method. The performance of all algorithms has been separately verified in the discrete time domain using simulations developed in the Matlab/Simulink environment. Finally, the functioning of the complete control strategy has been successfully checked in the same environment.

This paper presents the study and detailed analysis of converter losses at different stages together with the series-series (S-S) compensating coils in wireless power transfer (WPT) systems, via two distinct approaches to control the power converters. The two approaches towards wireless DC–DC power flow control are termed as the Single Active High-Frequency Wireless Power Transfer (SAHFWPT) system and the Dual Active High-Frequency Wireless Power Transfer (DAHFWPT) system. The operation of converters in SAHFWPT and DAHFWPT are controlled by the extended phase shift (EPS) and dual phase shift method respectively. The general schematic of the SAHFWPT system consists of an active bridge and a passive bridge, while the schematic of the DAHFWPT system consists of both active bridges. The efficiency evolutions of ideal SAHFWPT and DAHFWPT are far away from the real ones. Moreover, this article analyzes the operation and losses of the uni-directional power flow of the WPT system, i.e., from the DC bus in the primary side to the battery load in the secondary side. The loss estimation includes high-frequency switching losses, conduction losses, hard turn on and turn off coil losses, etc. Moreover, the efficiency of the WPT system depends on operation of the converter. A 50 W–3600 W Power range system at a resonant frequency of 85 kHz is implemented in MATLAB/SIMULATION to demonstrate the validity of the proposed method.

The wireless power transfer systems represent a viable solution to make more user friendly the procedure of charging the battery of electric vehicles. The performances of these systems are greatly affected by their compensation networks and are usually studied by considering their first harmonic equivalent circuits. This paper presents a new approach to writing the equations that describe these circuits and expresses them in a form that highlight the contribution of the coupled coils and of their compensation networks. The procedure to obtain the equations is described in details and the equations themselves are analyzed to derive from them the qualitative characteristics of the wireless power transfer system. In the last part of the paper a numerical analysis of a study case is reported, supporting the results by means of simulations.

This paper proposes a single-phase isolated buck power converter system that extracts and transmits the oscillating ripple energy of the primary buck inductor current to the secondary coil. This topology is a modification of the conventional buck configuration in which the single power inductor is substituted for by a pair of coupled inductors to build an isolated secondary output. The secondary coil delivers the required power due to the time-varying magnetic field developed by the oscillating part of the primary inductive current. Hence it eradicates the requirement of setting up a separate DC regulated supply for the main switch of the buck converter and results in a DC-DC switching converter, including a primary coil besides the existing typical wired output of the buck converter. This paper addresses the relevant operating principle and offers results for the simulation prototype by using a single-phase isolated buck structure, which attains simultaneous Buck conversion of conventional output and delivers the power to the secondary load as well.