The wireless power transfer (WPT) method for electric vehicles (EVs) is becoming more popular, and to ensure the interoperability of WPT systems, the Society of Automotive Engineers (SAE) established the J2954 recommended practice (RP). It includes powering frequency, electrical parameters, specifications, testing procedures, and other contents for EV WPT. Specifically, it describes the ranges of self-inductances of the transmitting coil, the receiving coil, and coupling coefficient (k), as well as the impedance matching values of the WPT system. Following the electrical parameters listed in SAE J2954 RP is crucial to ensure the EV wireless charging system is interoperable. This paper introduces a method for adjusting the effective permeability of the ferrite blocks in the standard model, to tune the self-inductance of the coils as well as the coupling coefficient. To guarantee the given values of the self-inductance of the coil and coupling coefficient matched those in the standard, we slightly modified the air-gap between the ferrite tiles in a specific region. Based on this method, it was possible to successfully tune the self-inductance of the transmitting coil and receiving coil as well as the coupling coefficient. The proposed method was verified by simulation and experimental measurements.

Silicon carbide (SiC) devices can significantly increase power efficiency, temperature reliability, power capacity, and power density because of their outstanding characteristics. Nevertheless, in the bridge-leg configuration of a power converter, the high-speed switching capability of SiC mosfets is often restricted by the coupling noise between high-side mosfet and low-side mosfet. The coupling noise caused by high ${dv/dt}$ and ${di/dt}$ in switching transient will increase the switching loss and the risk of mosfet breakdown. In order to completely take advantage of the superior feature of SiC mosfets, a novel multilevel gate driver is proposed in this article to mitigate the coupling noise effectively. Compared to the conventional gate drivers, the proposed gate driver adds a capacitor, an auxiliary mosfet, a Zener diode, and two resistors to regulate the turn-off voltage bias felicitously. In this article, the operation principle of the proposed gate driver is first introduced, to the best of our knowledge. Moreover, to obtain the circuit parameters accurately, a series of formulas have also been derived by equivalent circuit models. A 230-V/4.6-A synchronous buck converter based on SiC mosfets is successfully experimented to verify this proposed gate driver.

In this article, a nonconformal and non-overlapping domain decomposition method (DDM) based on surface integral equation (SIE) is proposed for the electromagnetic (EM) scattering or radiation of multiscale metallic targets. In order to reduce the unknown amount of the conventional SIE for multiscale EM simulation, we apply curved triangular elements and higher order hierarchical vector (HOHV) basis functions to the SIE. Next, to increase the flexibility of geometrical modeling and accelerate the convergence of the presented SIE system for electrically large and multiscale metallic targets, a DDM scheme is further developed to employ a discontinuous Galerkin (DG) approach to glue conformal/nonconformal surface grids between adjacent subdomains. In addition, an interior penalty term is introduced to stabilize the DDM solution, and half edge-based HOHV basis functions are introduced to model the current associated with nonconformal surface elements. Meanwhile, the basis expansion and recombination (BER) technique is introduced to significantly accelerate the matrix-filling and improve the efficiency. The flexibility of basis order selection is further enhanced by the hierarchical characteristic of HOHV bases. Finally, several numerical results are provided to demonstrate the accuracy, efficiency, and flexibility of the proposed HO-DG-DDM.

This paper proposes a new control method to regulate the power flow into multiple receivers. This system consists of one transmitter controller and three receiver controllers. They work independently to decide the power distribution with their combined operation. The simulated and experimental models have been built, and the experimental results are in good agreement with the theoretical analysis results. The proposed method is robust, flexible, and generalizable, and can be employed under various wireless charging conditions.

This paper proposes an orthogonal concave coupling mechanism based on wireless charging for unmanned aerial vehicles (UAVs); the original edge adopts a concave transmitting coil. So as not to occupy the gimbal position at the receiving end, the receiving coil is installed on the landing gear of the UAV perpendicular to the transmitting coil to form an orthogonal coupling magnetic field. This study conducted a finite element simulation of the coupling mechanism using Ansys Maxwell to test the mechanism’s coupling capability and anti-offset performance. The spatial distribution of the system’s magnetic field was constrained, and the magnetic flux leakage of the system was reduced by optimizing the transmitter structure. The system employed a double-sided LCC compensation topology network and used wireless communication to achieve constant voltage/constant current closed-loop control. Finally, the experimental platform was built, and the results show that the system output power was able to reach 960 W with 85.7% efficiency, and could realize the closed-loop control of charging with 48 V constant voltage and 20 A constant current. The system has the advantages of being small in size, lightweight (290 g) and easy to install, and the receiver device has strong resistance to offset.

While the filtered-x normalized least mean square (FxNLMS) algorithm is widely applied due to its simple structure and easy implementation for active noise control system, it faces two critical limitations: the fixed step-size causes a trade-off between convergence rate and steady-state residual error, and its performance deteriorates significantly in impulsive noise environments. To address the step-size constraint issue, we propose the switched step-size FxNLMS (SSS-FxNLMS) algorithm. Specifically, we derive the mean-square deviation (MSD) trend of the FxNLMS algorithm, and then by comparing the MSD trends corresponding to different step-sizes, the optimal step-size for each iteration is selected. Furthermore, to enhance the algorithm’s robustness in impulsive noise scenarios, we integrate a robust strategy into the SSS-FxNLMS algorithm, resulting in a robust variant of it. The effectiveness and superiority of the proposed algorithms has been confirmed through computer simulations in different noise scenarios.