This article presents a novel design approach for a six-plate horizontal coupler for underwater capacitive power transfer (CPT). The coupler comprises four power transfer plates and two shielding plates that effectively prevent external interference and reduce its potential as an interference source. Unlike prior six-plate CPT coupler designs, this approach employs different dielectric materials between the plates. Specifically, water acts as the dielectric between the transmitting/receiving side plates, whereas air is used between the same-side power transfer plates and shielding plates. This selection of materials significantly reduces the ratio of self-capacitance to mutual capacitance due to the high permittivity of water as compared to air. Consequently, the coupling coefficient of the six-plate coupler is enhanced, leading to increased efficiency while maintaining electric field shielding. Experimental results from a 5-kW prototype with 200-mm side length plates and 10-mm air layer thickness demonstrated a dc–dc efficiency of 87.2% over a 60 mm distance in freshwater testing. Additionally, the coupler demonstrated relative insensitivity to misalignment, with the efficiency remaining at 84.3% when offset by 50 mm and 81.4% for a transfer distance increase to 100 mm. These findings highlight the potential for this novel design to be utilized in challenging underwater transfer scenarios.

Capacitive power transfer (CPT) has garnered significant interest in recent years, driven by efforts to enhance power and efficiency. This article presents advancements in CPT technology, focusing on the design of a novel five-plate coupler and the optimization of CPT systems. The proposed five-plate coupler features single-side shielding, which aims to simplify design complexity and reduce costs while maintaining performance. This study characterizes the five-plate coupler and compares its performance to traditional even-numbered plate configurations, highlighting the differences between odd and even plate designs and the unique characteristics of asymmetric couplers. In addition, the factors influencing efficiency are investigated, and an optimization method for CPT systems with asymmetric couplers is proposed to enhance the overall system performance. Experimental validation includes the development of a 5-kW prototype CPT system with a 100 mm airgap, achieving an impressive efficiency of 96.5%. These findings underscore the potential of the proposed design and optimization approach to set new benchmarks for CPT systems, facilitating their broader application in high-power scenarios.

A half-turn transformer with symmetrical magnetic flux is proposed for high-frequency isolated DC/DC converters. The transformer structure can reduce the minimum number of turns from 1 to 0.5. By adopting a novel winding and circuit configuration, a symmetrical magnetic flux is realized to make full utilization of the ferrite core. A simple EI core, which is easily manufacture and commercially available, can be used to make the half-turn transformer. The operation principles of the transformer are analyzed and simulated. The performance of the transformer is experimentally evaluated on a 750 kHz, 380/12V, 600 W LLC converter using gallium nitride (GaN) devices with a peak efficiency of 98%.

Inductive power transmission technology provides a new way to solve the energy problem of autonomous underwater vehicles (AUVs). The performance of the magnetic coupler determines the system transfer capacity. A novel open‐type magnetic coupler with a simple structure, lightweight, strong anti‐misalignment performance and high self‐inductance stability is proposed for the arc‐shaped shell of AUV. The proposed magnetic coupler employs an arc‐shaped transmitter and the receiver uses an H‐shaped ferrite core to realize the close coupling of magnetic flux in the vertical direction. The parameters of the magnetic coupler are optimized based on ANSYS Maxwell simulation, which ensures its coupling performance and anti‐misalignment performance while minimizing the volume and weight of the receiver. To verify the proposal, a wireless charging system with a 183.9 g receiver is built. The maximum self‐inductance change rate of the coil and maximum coupling coefficient change rate under the conditions of axial misalignment from −25 mm to 25 mm and rotational misalignment from −10° to 10° are 2.9% and 14.3%, respectively. In the case of full alignment, it can deliver 735.6 W at a DC‐DC efficiency of 90.87%.

This paper proposes a passive transient current balancing method for multiple paralleled SiC-MOSFET half-bridge modules. The transient currents of the paralleled SiC-MOSFETs could be significantly different from each other because of the parameters mismatch, which induces significantly uneven switching losses distributions among the paralleled SiC-MOSFETs. Therefore, a passive transient current balancing method is proposed to deal with this issue. The proposed method does not rely on sensors and feedback control, so it is simple and easy to implement. Moreover, the proposed method can be easily extended to any number of paralleled SiC-MOSFET half-bridge modules. The operation principles and the parameters design of the proposed method are analyzed and presented in this paper. The performance of the proposed transient current balancing method is evaluated on an experimental set-up with three paralleled 1700V/300A SiC-MOSFET half-bridge modules.

Inductive power transfer (IPT) technology is widely used because of its high convenience especially for charging of electric vehicles. It has remained a high failure rate in recent years due to the large number of semiconductor components they contain. In this article, to address the problem that rectifier with constant-current output characteristics in the IPT cannot occur to open-circuit fault, a rectifier protected method based on SS type IPT system is designed. First, the hazards and impacts on the system after a diode fault are analyzed. Then, a method for parameter design of protective devices have developed that does not affect the compensation parameter design of the original system, which maintain high efficiency operation after open-circuit fault, and a fault detection technology based on dc bias of the fault eigenvalue is proposed. This article solves the problem that the rectifier cannot be open-circuit faulted of the traditional IPT constant-current topology, which improves the reliability and safety of the system. Finally, experiments under different loads verify that the system rectifier can maintain an operating state with an efficiency of 91.78% after a diode open-circuit fault occurs, as well as the accuracy of the fault detection method.