Nowadays, work on Wireless Power Transfer (WPT) systems with dual active bridges is attracting great attention due to their low conduction losses, power regulation, load transformation and reactance compensation. However, in these studies limitations such as overall analysis, design and realization techniques of the system were not considered properly. To address the aforementioned issues, this paper presents a detailed analysis, design and realization of a Series-Series (SS) WPT system with dual active bridges, which will improve the overall performance. Three independent Phase Angles (PAs) have been analyzed and designed in this study, one PA on the primary side and the other two PAs on the secondary side. This Multiple Degrees of Phase Control (MDPC) method can achieve additional reactance compensation, load transformation and output regulation simultaneously. To realize the proposed method in practice, key implementation techniques have been investigated in detail, including additional reactance estimation, mutual inductance estimation, phase detection and synchronization. The feasibility and effectiveness of the proposed system is verified through simulation and experimental results.

Due to the diversity of chassis heights, battery types, and battery capacities, wireless power transfer (WPT) systems for electric vehicles (EVs) have large variations in Z classes, battery voltages, and output power levels. Conventional solutions require different DC/DC converters, compensation circuits, and coupling coils for each specification, which results in weak compatibility, increased cost, and increased difficulty in development and product management. This article analyzes the influence of parameter variations on the EV WPT system mathematically. Then, a series-parallel transformer-based architecture is proposed for the high-power EV WPT system. The generalized power transfer function of the proposed system is derived. In addition, the design principle is demonstrated in detail, which can adapt to different Z classes, battery voltages, and power levels. A 20-kW LCC-LCC WPT prototype with a maximum DC/DC efficiency of 94.2% is built to demonstrate the feasibility of the proposed system. This paper is accompanied by a video file demonstrating the 20-kW experiments.

Wireless power transfer charging of modern electric vehicles is complicated by widely varying charging battery pack voltages between different models. This article proposes a new resonant inductor integrated-transformer (RIIT)-based receiver. It is compact, low cost, and can adapt to different battery pack voltages without any significant change of resonant parameters. The design approach, power losses, and power transfer capacity of the proposed system are presented. In addition, methods of natural current sharing and voltage sharing among different RIITs are proposed. An LCC-LCC WPT prototype compatible with both 400 and 800-V battery pack voltages is built, and the system efficiency reaches 94% at 9.5 kW, which verifies the feasibility and performance of the proposed receiver.

Electric vehicles with different output power levels can use wireless power transfer (WPT) systems. Different vehicle assemblies (VAs) may be charged by different ground assemblies (GAs) in charging stations. However, the overall efficiency of the WPT system may drop significantly when the power class difference between GA and VA is large. To address this issue this article proposes a dc-link parallel ac-link series multi-inverter multirectifier architecture for high-power WPT systems. Modulation, power transfer capability, and power sharing from the design aspects are investigated. A detailed power loss analysis and an easy-to-implemented power loss optimized control method based on mutual inductance identification are presented in this article. Finally, experimental results are obtained from a 20-kW LCC-LCC WPT system to validate the analysis and proposed system operation.

Conventional high-power wireless power transfer (WPT) systems that are required to deliver power over a wide operating range suffer from issues like hard switching, poor current sharing, and unwanted cross-coupling issues. This article proposes a new resonant inductor integrated-transformer-based multi-inverter to improve the WPT power rating without compromising performance. Viable modulation schemes of the proposed system are analyzed, and a hybrid modulation scheme is proposed for wide-range power regulation. To further investigate the feasibility of the proposed system, the power transfer capacity, current sharing among multiple inverters, and the soft switching regions are studied. A 14-kW LCC – LCC WPT experimental system with three parallel inverters is built, which achieves 93.5% efficiency, demonstrating the high performance of the proposed system. This article is accompanied by a video demonstrating these experiments.

Smart microimplants are playing increasing roles in modern medicine. Wireless power transfer (WPT) and data communication are essential components in microimplants. In order to minimize device size, a preferred design is to share the wireless power channel with the data communication links consisting of a downlink and an uplink. While the implementation of the downlink is relatively easy, the uplink from the implant to the external unit is difficult to implement due to the limited power supply and small transceiver coil available within the implant. In this work, we present a new design of the data uplink that utilizes a special tapped coil and a simple passive circuit to produce a strong pulsed magnetic field (PMF) for signal emission. The strong PMF, which is oscillatory at the same resonant frequency as the WPT carrier, allows wireless data transmission over a longer distance through the WPT channel. Our new design is studied analytically, and the function of our circuit is confirmed by a computer simulation. A prototype is constructed, and its performance is compared with the existing load shift keying (LSK) method. Our experimental result showed that the design produced more than 15 times stronger signal strength at the receiving end.