In this paper, a robust wireless power transfer system is proposed with self alignment capability and controllable output current characteristics for static charging of automatic guided vehicles (AGVs). A reconfigurable circuitry is designed to work initially in an inductor-capacitor-capacitor-series (LCC-S) compensation mode for achieving magnetic field self alignment, then switched to an LCC-LCC configuration for wireless charging. Apart from the passive components used for wireless power transfer, no additional components such as cameras, sensors, or dedicated sensing coils are needed for self alignment. The induced voltage of a series tuned Q-coil on the load side is used for the AGV to automatically adjust its position. The vehicle will be self aligned when the induced voltage becomes null, then the system is switched to a controllable constant current (CC) charging mode. A prototype is built which demonstrates that the output charging current is controllable and can be kept constant against load variations. The experimental results show the proposed system can realize an 89.1% dc-dc power transfer efficiency (PTE) at an output current of 30A and output voltage of 48V.

Unwanted cross-couplings greatly hinder the development of double-receiver wireless power transfer (WPT) systems. Whenever the air gap changes or misalignment occurs, cross couplings disrupt the system stability. This article investigates a magnetic coupler for a double-receiver WPT system, which dramatically suppresses the unwanted cross-couplings. Two types of undesirable couplings are significantly reduced by using orthometric DD coils and Q-shaped coils. First, the unwanted couplings between receivers can be eliminated, validated by the measured coupling coefficient k _AB = 0.003. Therefore, two receivers can work independently. Second, the unwanted couplings among the source coil and receivers can be eliminated ( k _1A = 0.003 and k _1B = 0.003), resulting in load-independent constant voltage output. Compensation networks can also be designed straightforwardly. In addition, the inverter can achieve zero phase angle, alleviating volt-ampere rating and increasing efficiency. Thanks to the presented structure, this coupler design process is efficient because the decoupling is from the shape rather than turns. Also, it can be easily generalizable to other output voltage or power levels since turns can be changed to meet different charging demands. Validated by a laboratory prototype, experimental results successfully show remarkable agreement with the theoretical analysis, ensuring 72 V load-independent constant output voltages. It also realizes a 90.16% maximum measured overall dc–dc power transfer efficiency with 12 cm air gaps when delivering 518.4 W to two 20 Ω loads.

This article proposes an advanced framework for wireless charging systems in remote aerial vehicles (RAVs) that integrates magnetic coupling structures with multicoupling LCC-LCC compensation topologies. Unlike existing systems that focus on limited axis misalignment, the proposed system accommodates full 360° rotational misalignment, allowing the UAV to land freely and charge in any orientation thanks to the carefully optimized turn numbers and spacings. As a result, the system supports a broad charging zone with lateral misalignments of Δx ∊ [−100 mm, 100 mm], Δy ∊ [−70 mm, 70 mm], and full 360° rotational freedom. Under such a large charging area, the proposed coupler consistently delivers key benefits such as quasi-load-independent output and zero-voltage switching (ZVS). The proposed optimized magnetic coupler, by exploiting the inherent cross-coupling capabilities within the multicoupling LCC-LCC compensation network, effectively expands the ZVS region in the designed charging area.

This paper proposes a new method for simultaneous dynamic wireless power and data transfer (SDWPDT). When the receiver is moving, both power and data transfer channels are dynamically switched ON/OFF according to the receiver’s position. In essence, data is transmitted through the high-frequency electric field (EF) generated by the parasitic capacitances of the coupling coils and the metal shield plates, while power is transmitted through the relatively low-frequency magnetic field (MF) generated by coupling coils. By doing this, mutual interference between two transfer channels (i.e., power and data transfer channels) is relatively small. Firstly, the interference from power to data can be greatly reduced due to the absence of a direct electrical wire-based connection. Secondly, the power loss caused by the data transfer channel in the power link is very small so it can be ignored. In addition, the implementation of real-time communication facilitates the establishment of a closed-loop control within the system. This mechanism guarantees consistent power output during dynamic movement, even in the presence of fluctuations in load or input voltage. Laboratory prototype-based experimental findings substantiate the feasibility of the proposed approach.

This article presents a new resonator design scheme for wireless battery charging systems of electric bicycles (EBs). The newly designed method is established based on a switched series (S)-series parallel (SP)/S compensation scheme and Helmholtz coils for the transmitting coils. The Helmholtz coils are adopted to ensure that the mutual inductance between the transmitting and receiving coils is invariant. For this reason, the switched S-SP/S compensation scheme can be used to implement load-independent constant current (CC) and constant voltage (CV) charging for the battery loads instead of using the conventional LCL or LCC compensation schemes. The advancements of the proposed design, as compared to the conventional methods for wireless EB charging, are more than constant mutual coupling and elimination of compensated inductors. The communication channel between the transmitter and receiver, additional user-end converter, and complicated control algorithms can also be annihilated. Simulation results using Maxwell verify that the mutual inductance of the proposed resonator is constant. Experimental results validate that the output current and voltage can be well-regulated to track the references at 1.2 A and 24 V, respectively, at different load conditions. Especially, the maximum efficiency can reach 97.17% in the CC charging mode, whereas 91.17% in the CV charging stage. The maximum output power is 115 W on the load side. This design can be generalizable to other power levels to meet different charging demands.

In this article, a special magnetic coupler for three-coil wireless power transfer (WPT) is proposed to eliminate the mutual inductance between the source coil and the receiver coil, which can significantly improve the design freedom. Specifically, unipolar Q coil, mixed QDD coil, and bipolar DD coil are designed for the source coil, the transmitter coil ( $\text{T}_{\mathrm {X}}$ ), and the receiver coil ( $\text{R}_{\mathrm {X}}$ ), respectively. By making use of unipolar coils and bipolar coils, this structure magnetically decouples the receiver coil from the source coil. Meanwhile, under different lateral misalignment conditions, this new coupler facilitates maintaining high efficiency. A laboratory prototype has been constructed to validate the proposed structure, demonstrating that the proposed structure can realize inherent characteristics, enhance misalignment tolerance, and energy transfer. The potential applications are EV systems, but this design can be generalizable to other three-coil systems.