Wireless charging technology has become an important development trend in future electric vehicle (EV) power supply technology due to its safety, flexibility, and convenience. With its industrialized development, interoperability has become an essential technical link. The interoperability of wireless charging systems refers to the ability of output performance to meet specified indicators when different transmitter and receiver devices are matched. This study reviews the research status of the interoperability of EV wireless charging technology. First, the definition and composition of the interoperability of wireless charging systems are briefly given. Then, the article provides a review of standards about interoperability so far. The interoperability of various magnetic couplers and compensation topologies is also analyzed and summarized. After that, the paper reviews the existing interoperability evaluation methods. Finally, this work highlights the existing problems and challenges in current research of interoperability. We hope that this work will contribute to the further development of EV wireless charging technology.
Existing research on the magnetic coupler of unmanned aerial vehicle (UAV) wireless charging systems usually ignores the UAV fuselage, but the fuselage causes eddy current loss and reduces a system’s efficiency. Therefore, aiming at the above problems, this paper proposes a design for a magnetic coupler using nanocrystalline cores to reduce the loss caused by the UAV fuselage. First, the parameters of the asymmetric circular coils were designed for higher mutual inductance. The losses caused by the windings and cores were also calculated. Second, for the loss effect of the carbon fiber fuselage, the fuselage was modeled as an additional coil coupled with both the transmitting and receiving coils. The fact that the eddy current induced by the fuselage leads to efficiency reduction is revealed, which has been generally ignored by previous research. Then, the effect of the nanocrystalline alloy was analyzed based on the magnetic circuit model. An optimized nanocrystalline alloy film was applied to reduce eddy current loss and improve coupler efficiency. Finally, an experimental prototype with a 500 W output, 90.3% efficiency, and a 300 mm air gap were fabricated. When compared to the design without UAV material considerations, the coupler efficiency was improved by 7.9%.
17 July 2024 in IEEE Transactions on Power Electronics
The impedance-based interoperability evaluation is a commonly used testing method to guarantee interconnection and interoperability among different wireless charging devices. Its advantage lies in using reference devices to avoid extensive cross testing. However, the manufacturing tolerances and the parameter drift of the reference devices often result in deviations of the tested values from the standard, increasing misjudgment rates. This incurs in the need of determining boundaries and tolerance zones to characterize the uncertainty of test results, which still lacks clear methods. To solve this problem, this letter introduces a characterization model for the correlation between port impedance and interoperability according to volt–ampere requirements for coils and power electronics. Then, a method for determining tolerance zones through error transfer functions is proposed. Finally, the effectiveness of the proposed tolerance zones in identifying the uncertainty propagation from parameter drift to test results is verified by the designed experiment. Given a manufacturing tolerance or parameter drift of ±2%, the interoperability evaluation indicated by the proposed tolerance zones can provide a more precise classification assessment for 20% of interoperable devices.
Wireless electric vehicle charging technology is developing in the direction of high power levels. However, more generated heat brought by higher power will accelerate the system’s aging and can even lead to damage. An excellent thermal design for the magnetic coupler can reduce each part’s maximum temperature, ensuring long-term operation reliability. Therefore, in this article, the magnetic coupler’s thermal estimation and design are studied based on a 6.6 kW wireless electric vehicle charging system. First, the calculation method of internal resistance of a litz coil, core loss, and eddy current loss of a shielding aluminum plate are studied. Considering the influence of thermal fields on material properties, each part’s power loss calculation formula is further modified to improve the accuracy. After that, heat dissipation research is carried out. The heat dissipation measures, such as filling the surface of the shielding aluminum plate with thermal conductive silicone grease, are proposed. Finally, the effectiveness of the heat dissipation measures is verified by simulation and experiments. The experiment shows that the error between the power loss value of each part calculated by simulation and measured by the experiment is less than 15%, and the maximum temperature of the magnetic coupler is controlled below 80 °C.
11 July 2025 in IEEE Transactions on Power Electronics
To address the challenges of uncrewed aerial vehicles (UAVs) landing misalignment, low payload capacity, and electromagnetic compatibility requirements, this letter proposes a novel magnetic coupler with high misalignment tolerance. The bipolarly magnetized solenoidal transmitter generates a rotating horizontal magnetic field, which is simultaneously captured in both axial and radial directions by the multichannel conformal receiver conformally integrated into the UAV landing gear. This configuration ensures robust adaptability to rotational, axial, and radial misalignments while suppressing leakage magnetic flux around the UAV’s fuselage. Experimental results validate the system’s performance, achieving a maximum output power of 425 W with a dc–dc efficiency of 81.6%, and exhibiting maximum fluctuations in output voltage and efficiency of only 2.7 V and 3.5%, respectively, under diverse misalignment conditions.
Wireless power transfer (WPT) systems for autonomous underwater vehicles (AUVs) are gaining traction in marine exploration due to their operational convenience, safety, and flexibility. Nevertheless, disturbances from ocean currents and marine organisms frequently induce rotational, axial, and air-gap misalignments, significantly degrading the output power stability. To mitigate this issue, this paper proposes a novel reconfigurable WPT system utilizing coaxial antipodal dual DD (CAD-DD) coils, which strategically switches between a detuned S-LCC topology and a detuned S-S topology at a fixed operating frequency. By characterizing the output power versus the coupling coefficient (P-k) profiles under both reconfiguration modes, a parameter design methodology is developed to ensure stable power delivery across wide coupling variations. Experimental validation using a 1.2 kW AUV charging prototype demonstrates remarkable tolerance to misalignment: ±30° rotation, ±120 mm axial displacement, and 20–50 mm air-gap variation. Within this range, the output power fluctuation is confined to within 5%, while the system efficiency exceeds 85% consistently, peaking at 91.56%.