This paper proposes a modular magnetic integration design for EV wireless power transfer (WPT) systems such that the magnetic field generated by the compensation and transmitting coils are exploited to enhance the power transmission capacity. An integrated coil along with a compensation method are proposed to enable magnetic field enhancement without any reactive power flow between the compensation and the transmitting coils, and to achieve input zero phase angle (ZPA) and constant current (CC) output. The proposed design offers misalignment tolerance to stabilize the system output under any random misalignment. The feasibility of the proposed topology is investigated through the equivalent circuit modeling and analysis. A finite element analysis (FEA)-based optimization algorithm is also developed to expedite the design process without compromising the accuracy. Analytical and simulation results confirm the advantage of the proposed design in eliminating the leakage magnetic field while enhancing the transmission flux density. Finally, a scaled-down WPT prototype is built and tested to verify the performance and effectiveness of the design. This work provides insights into possible modular integration design of the high-order compensation topologies featuring higher compactness, magnetic field enhancement, reduced leakage field, and misalignment tolerance for WPT system.

A novel high voltage operation featured wireless power transfer system for monitoring equipment charging on 110 kV high voltage transmission line based on magnetic resonant coupling is studied and designed. With consideration of operation environment on transmission line and electrical transmission tower, an overall scheme is proposed through installation position, coupling structure and driving topology design. In order to improve system's suitability in high voltage environment, related optimization methods, including constraining power flow path, improving quality factor and coupling have been adopted. Since the coupling coils are fixed at both ends of insulator string, barrel shaped high permeability material layer is added to constrain the magnetic field distribution. Moreover, cross-impacts between transmission line and the charging system are analyzed. The influence of power frequency magnetic field on charging system is calculated and electric distribution of insulator string with the charging system are simulated. Analysis results indicate that cross-impacts can be negligible. Experimental results verify that the transmission power can meet power supply requirements and the designed charging system can be operated stably under high voltage condition.

This article presents a cost-effective dynamic wireless power transfer (DWPT) system for efficient and stable output power charging of autonomous moving equipment. The proposed system is realized based on a low-cost segmented configuration and a flexible operating strategy. Specifically, the configuration is a combination of a dynamic T -series/series topology and extended transmitter (Tx) coils. The topology eliminates the cross-coupling impact of adjacent Tx coils and tunes the dynamic circuits at resonance. It makes the switching circuits equivalent to a unified analytical model for simplified control, which reduces the cost of inverter, decoupling, compensation, and position detection in the DWPT. The extended Tx coil with a simplified structure, which is obtained from winding coupling characteristics and a finite-element analysis based algorithm, is proposed to improve the moving misalignment tolerance, thereby reducing the number of Tx segments. An operating principle with three modes behind the proposed strategy is designed to fully utilize the efficient coupling area of individual Tx segment and improve the efficiency in the transition region from one segment to the other one. The operating parameters including the transition and compensation are obtained based on the topology and its operating principles. Position detection and power regulation methods are developed and embedded in the system control to configure/coordinate the segmented coils as the strategy and mitigate power fluctuation in the transition region. The performance and effectiveness of the proposed cost-effective DWPT system are evaluated based on experimental results on a scaled-down prototype.

This paper presents a quasi-uniform magnetic coupling based effective-configuration wireless power transfer (WPT) system for drones wider-area charging with multiple extended transmitter coils. The extended transmitter coil with two windings is proposed to cooperate with a small receiver coil for misalignment tolerance with efficient and quasi-uniform coupling. The extended coil is worked out by a simulation-based algorithm, which can be implemented by simple and low-cost procedures. Independent-operating multiple extended coils are designed with overlaps and a dynamic topology for low-cost and robust charging area extension according to performance analyses. Moreover, a novel landed position detection method based on the negative coupling characteristic of the extended coils is proposed for system configuration. The design enables cost-effective charging area extension, and assists to sense the position of drones. A prototype is established with a charging area nearly 20 times the area of the receiver coil. Experimental results prove the feasibility of the design, which can be applied flexibly.

The wireless power transfer (WPT) system has been extensively studied for its safety, convenience and aesthetics, and has gradually been introduced into our life applications. In order to maintain battery performance, constant current (CC) and constant voltage (CV) charging outputs are generally regarded as the dominant charging modes. However, battery equivalent resistance changes significantly during the charging, so it is difficult to simultaneously achieve load-independent CC and CV charging outputs and zero phase angle (ZPA) condition. This paper proposes a new LCCC/S topology and its corresponding parameter tuning method to obtain CC and CV charging modes at two different ZPA operating frequency points, respectively. In addition, it is worth mentioning that the receiver has only one compensation capacitor, which follows the principle that the receiver of the WPT system should remain compact and portable. Furthermore, a simple frequency modulation controller is designed to solve the problem of inaccuracies of the charging outputs due to parasitic losses of components and fluctuations of DC input voltage. Finally, a verification setup with 3A output current in CC mode and 48V output voltage in CV mode was built to validate the feasibility and rationality of the proposed LCCC/S compensated WPT system and the corresponding control method.

In this article, an optimized design for a dual-coupled inductor–capacitor–capacitor-series ( LCC -S)-compensated wireless power transfer (WPT) system with zero-phase angle (ZPA) input condition and load-independent constant current (CC) output is presented. To this end, based on the misalignment characteristics of the reversed-series compensation coil structure, a novel design method for determination of the compensation parameters is proposed. By introducing a stability factor, any restriction on the variation correlation of the mutual inductances between the transmitter and receiver coils, and between the compensation and receiver coils within the range of misalignment tolerant design, is eliminated, thereby increasing the degree of freedom in the coil structure. According to a predetermined misalignment tolerant range, the proposed method can limit the fluctuation of the output current within a certain range and maintain the ZPA input condition. A 200-W/85.3-kHz prototype based on the proposed method is implemented and its performance is experimentally validated. The system can operate in ZPA input and load-independent CC output with a misalignment tolerance factor of 4, as the load varies from 5 to 20 $\Omega$ .