Wireless power transfer (WPT) systems have been hamstrung by modest energy efficiencies and electromagnetic safety concerns. Conventional electromagnetic shielding devices can reduce the electromagnetic interference (EMI) to the ambient environment but at the same time deteriorate the transfer performance. In this article, a novel hybrid resonance optimization-based passive shielding magnetic structure and the corresponding circuit are proposed. The shielding structure and topological network have the advantage of minimizing electromagnetic fields (EMFs) around the system while guaranteeing transfer performance (PTE, G_V, P_OUT, phase relation) constant. Moreover, a multiobjective genetic algorithm is utilized to optimize the shielded directional coils (SDCs) parameters in consideration of the transfer efficiency, EMF, and shielding structure volume. Finally, a reasonable prototype of the proposed WPT system is designed, fabricated, and tested. Experimental results show that the maximum leakage EMF level in the evaluated area is reduced by 4.18 dBmV (nearly 39.5 µT). Additionally, the PTE changes by only 1.5%, the G_V changes by just 9.5%, and the phase relationship remains unaffected under the 80 W output power condition. The presented solution merges design approach, compensation network, and optimization plan. It can be further extended to analyze arrays of arbitrary order and shielding in different orientations, providing useful insights for smart homes.

To enhance the battery endurance of unmanned aerial vehicles (UAVs), this article addresses key issues in traditional wireless power transfer (WPT) systems. These issues occur during constant current/constant voltage (CC/CV) switching, such as poor stability, high payload, power loss, and charging instability. Accordingly, a WPT system based on topology switching is proposed. First, a lightweight compensation topology based on LCC-Series compensated topology (LCC-S) is designed. A tuning capacitor is incorporated, and two switches regulate the switching of the compensation capacitor to realize CC/CV mode transition. Meanwhile, the impedance matrix model is built to find optimal compensation component values, maximizing energy transfer. To reduce sensitivity to misalignment, a “+” shaped compensation coil is added to the basic 2 × 2 square coil array. It improves magnetic field uniformity and suppresses flux leakage. Experimental results show that the system achieves stable load-independent output. Within horizontal offset [−150, 150] mm and diagonal offset [−150√2, 150√2] mm, it keeps output power over 150 W and efficiency over 70%, with strong anti-misalignment ability. This system effectively solves key challenges such as endurance bottlenecks, complex CC/CV switching, and weak anti-misalignment. It offers a reliable technical solution for efficient charging of autonomous UAVs.

Optimizing three-dimensional (3D) omnidirectional wireless power transfer (WPT) remains a challenging goal in modern power electronics systems. While several methods, such as orthogonal coil designs and current control strategies have been explored, they still struggle with high degree of freedom charging. Compared to conventional WPT systems, the cavity resonance method offers a promising alternative. This article proposes an opened quasi-static cavity resonance (O-QSCR) structure for this application, which generates a uniform magnetic field throughout the space by driving a wide, even current along its surface. Besides, a method for rapidly evaluating the magnetic field uniformity is introduced to optimize the cavity configuration of O-QSCR based on the magnetic field distribution. Following that, the performance of the proposed O-QSCR system is analyzed using transmission theory and validated through both electromagnetic simulations and experiments. Experimental results show that the transmission efficiency stays above 46% in 95% of the space and exceeds 20% even when the receiver rotates by 60° offset. The proposed system has the capability to light up LEDs at various positions and angles, offering an innovative and practical solution for omnidirectional charging in future 3D environments.

Compared to traditional inductive wireless power transfer (WPT) technology, quasi-static cavity resonator-based WPT (QSCR-WPT) systems can significantly inhibit transmission efficiency deterioration within room-scale space. However, a conductive pole is required generally in the middle of the cavity for a uniform magnetic field. Besides, the changes in receiver angles may cause fluctuations in efficiency and output power. To address these issues, a dual-excitation method is introduced to modulate a rotating magnetic field with uniform magnetic distribution and controllable direction in a QSCR-WPT system. This particular magnetic field configuration is referred to as the ubiquitous magnetic field with pole-independent (UMPI) mode in this article. Compared to the pole dependent (PD) and PI modes reported in the existing research, the UMPI mode exhibits superior tolerance to both angular and positional variations. Furthermore, the equivalent circuit model of the resonant cavity is established, and the electrical parameters between the coil and the resonant cavity are derived for the first time using the reflected impedance equation. Finally, the experimental results indicate that the receiver achieves full-angle wireless charging coverage in the majority of spatial locations within the cavity (over 90% of space).

In the field of uncrewed aerial vehicle (UAV) wireless charging, inductive power transfer (IPT) and capacitive power transfer (CPT) have become the two main technical approaches. However, existing single-topology systems still face significant challenges. This article proposes a hybrid IPT-CPT wireless power transfer (WPT) system to address key limitations of lightweight design and landing misalignment tolerance. First, a hybrid coupler is designed, with CPT serving as the main energy transfer channel. By reusing the compensation inductor as the coupler of IPT, the integration level of the system is improved. Then, a frequency-variable reconfiguration strategy with single-switch control is introduced to enable constant current (CC) and constant voltage (CV) output modes. Furthermore, a modified MOEA/D algorithm is employed to co-optimize electromagnetic parameters, balancing transmission efficiency and output power. Experimental results demonstrate that the system delivers 218.8 W with 86.38% efficiency in CC mode at 750 kHz and 216.6 W with 81.39% efficiency in CV mode at 778 kHz. The system exhibits strong misalignment tolerance, maintaining stable operation within $\boldsymbol{\pm}$25~mm (x-axis) and $\boldsymbol{\pm}$100 mm ($y$-axis) offset ranges.

Quasi-static cavity resonance wireless power transfer (QSCR-WPT) technology can achieve pervasive power delivery in room-scale range. The coupling model of the system has been established by several approaches. However, the accuracy of mathematical model is seriously limited due to the lack of direct measurement of the equivalent parameters of the cavity, which hinders the analysis and design optimization of the system. Additionally, the coupling model is difficult to analyze key characteristics, such as the voltage and current. To address this issue, a hybrid parameter extraction methodology is presented firstly and it combines long short-term memory (LSTM) networks with nonlinear least squares (NLS) optimization. Specifically, approximate equivalent circuit parameters are obtained using an LSTM network from the input impedance spectrum data. These parameters serve as initial values for the NLS algorithm, which then performs precise regression to yield precise circuit parameters. Thus, system performance can be represented and analyzed clearly. Experimental results demonstrate that the implemented methodology achieves 95.78% voltage prediction accuracy and 98.13% transmission efficiency estimation precision across the operational spectrum. This paper provides a novel perspective on the QSCR-WPT modeling and paves the way for further exploration of the parameter optimization and control methods of the QSCR-WPT.