This paper proposes a new control technique, which only employs the primary-side controller and load identification approach to adjust the charging voltage/current for both series-series (SS) and series-parallel (SP) compensated wireless power transfer (WPT) systems. The advantage is that dual-side wireless communication for real-time charging current/voltage adjustment is avoided as well as it is suitable for different charging modes, e.g. constant voltage (CV) and constant current (CC) charging defined by the battery charging profile. The load identification approach, which utilizes the reflected impedance theory and quadrature transformation algorithm for calculating the active power, is proposed to estimate the equivalent load resistance. Then, the CV/CC charging for both SS and SP compensation are achieved by PI controlled phase shift H-bridge inverter. The simulation and experimental results validate the feasibility of the proposed method. During the CC charging, the 3.01A and 3.03 A for SS and SP compensation with the error of 1.2% and 1.4% are achieved. During the CV charging, the 25.8 V and 25.7 V for SS and SP compensation with the error of 1.1% and 1.3% are realized. The proposed method improves the performance of both SS and SP compensated WPT systems to be more suitable for the applications that require compact and light weight receiver.

Charging current and efficiency of a wireless power transfer (WPT) system depend on the equivalent load resistance of supercapacitor load, which varies during charging. To achieve constant current (CC) charging and maximized efficiency under variable loads, control method that uses primary-side phase shifted H-bridge inverter and secondary-side semi-active rectifier are proposed. The secondary-side control method not only achieves CC charging, but also ensures no reactive impedance seen into the semi-active rectifier. On the other hand, the maximum efficiency tracking is based on searching the minimum system dc input current for any given output power and realized by the phase shifted H-bridge inverter controlled by the perturbation and observation algorithm. Experiments are performed to validate the feasibility of the proposed control method. During CC charging of 3 A, the maximum efficiency is 81% and the largest efficiency improvement is 15.2% at light load. The proposed method improves the system performance and is suitable for practical applications that require compact receiver and no wireless communication link between the transmitter and the receiver.

This review discusses the progress of research on sulfonated poly(ether ether ketone) (SPEEK) and its composite membranes in proton exchange membrane fuel cells (PEMFCs). SPEEK is a promising material for replacing traditional perfluorosulfonic acid membranes due to its excellent thermal stability, mechanical property, and tunable proton conductivity. By adjusting the degree of sulfonation (DS) of SPEEK, the hydrophilicity and proton conductivity of the membrane can be controlled, while also balancing its mechanical, thermal, and chemical stability. Researchers have developed various composite membranes by combining SPEEK with a range of organic and inorganic materials, such as polybenzimidazole (PBI), fluoropolymers, and silica, to enhance the mechanical, chemical, and thermal stability of the membranes, while reducing fuel permeability and improving the overall performance of the fuel cell. Despite the significant potential of SPEEK and its composite membranes in PEMFCs, there are still challenges and room for improvement, including proton conductivity, chemical stability, cost-effectiveness, and environmental impact assessments.

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.

In this paper, a novel magnetic coupler of wireless power transfer (WPT) system for the solar wing driving of the spacecraft is designed. Compared with the traditional slip-ring power supply, the proposed magnetic coupler is characterized by non-contact, high efficiency, wear-free, safety and reliability. Particularly, it can be applied to the rotating condition. To realize light-weight and small-volume of the receiver, the magnetic coupler has been optimized from both compensation topology and coil configuration. Firstly, a Series-None (S-0) topology is employed to eliminate the bulky secondary-side compensation capacitor. Secondly, a new nested solenoid coil with strip core (SCSC-type) is proposed to ensure miniaturization, stable power transfer and high efficiency. Finally, the experimental setup is built to verify the performance of the designed magnetic coupler. Experimental results are well-matched to simulations, demonstrating that the weight of the prototype is 1.3 kg and the transfer power is 3 kW at an AC-DC efficiency of 92.7%.