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.

Accurate estimation of mutual inductance in wireless power transfer (WPT) system is a prerequisite for accurate identification of load parameters, which is critical in system constant output and efficiency tracking control. In this article, a general load decoupling method for WPT system considering soft-start process and battery initial voltage is proposed. Moreover, a double-sided LCC topology is used to explain how to calculate the boundary conditions of load decoupling. Based on the proposed load decoupling method, a mutual inductance identification method is proposed for WPT system with double-sided LCC topology. Within the frequency range recommended, the unique solution of mutual inductance can be obtained by solving high-ordered equivalent impedance equation. In this case, there is no need to discuss the situation for multiple solutions. Based on the WPT prototype, the effectiveness of the proposed load decoupling method is verified, and parameter sensitivity of the identification method is analyzed in detail. Finally, the proposed method is experimentally verified. Results show that high identification accuracy can be achieved even when the coils are misaligned. Compared with the existing identification methods, the proposed method does not need any additional switches and auxiliary circuits, which reduces the complexity and system cost effectively.

This paper develops a method of input design for the identification of wireless power transfer (WPT) systems based on receding horizon D-optimization. The dynamic behavior of the system is characterized by a discrete-time, Single-Input, Single-Output (SISO) model, and the associated model parameters are estimated by a recursive least-squares method. To improve the quality of the parameter estimates, the excitation signal of the system is designed based on receding horizon D-optimization. To improve the convergence and efficiency of the input design process, the Sequential Quadratic Programming (SQP) method is employed to solve the receding horizon D-optimization. Numerical and experimental results are presented to demonstrate the effectiveness of the proposed method.

It is crucial for inductive power transfer (IPT) systems to achieve load-independent outputs. However, the complex charging environment brings a series of challenges to the parameter design of the IPT system. For example, in the case of wireless charging of electric vehicles, there are situations such as large load variation range and inaccurate coupling coil alignment, which requires the IPT system to maintain constant current (CC) and constant voltage (CV) outputs under variable coupling conditions. Therefore, this paper proposes a parameter design method for the double-sided LCC compensation network, which can decouple the CC and CV outputs from the mutual inductance parameter, and by changing the operating frequency, the CC output and CV output of the IPT system can be mutually switching, and with zero phase angle (ZPA) input at the same time. In this paper, the CC and CV output modes of the double-sided LCC compensation network is designed based on the two-port network, and then the ZPA input condition is deduced through the mutual inductance model. To maximize the system efficiency, an improved genetic algorithm is proposed to solve the system CC and CV output operating frequencies. Finally, a 3.3kW prototype and simulation model are established to verify the correctness of the theoretical analysis.

Accurate and fast identification for mutual inductance and load charging parameters of inductive wireless power transfer (IPT) system is essential for impedance matching, and the output control of communication-free IPT system. A joint real-time identification method for mutual inductance and load charging parameters of IPT system is proposed in this paper. Only via measuring the RMS value of fundamental voltage and current on primary side, the double equivalent impedance modulus equations about mutual inductance and equivalent load resistance are established. To obtain real-time identification results of mutual inductance and equivalent load resistance from the high-order implicit function equations, an improved adaptive filtering algorithm based on Least Mean Squares (LMS) is proposed. Then, the identification values of load charging parameters are obtained according to the identified mutual inductance and equivalent load resistance. Finally, a 3.6kW platform is built to verify the validity of the proposed method. And the experiment results show that, compared with other existing achievements, the proposed method can identify U_Bat , I_Bat , R_L and M simultaneously in real-time without changing the system operation, and it has faster rate and higher accuracy of identification.