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.

A load-independent wireless power transfer system with constant current and constant voltage output for electric vehicles charging is designed and optimized in this paper. Wireless charging system based on LCL-S or LCL-LCL compensation topology is systematically analyzed. And dynamic LCL-S/LCL switching topology is designed and simplified to achieve constant current in the transmitting coil and load-independent constant current and constant voltage output, which can be controlled easily. Moreover, the coupling structures composed of different coil shapes and shielding structures are comparatively studied to improve the coupling stability under misalignment. Figure-of-merit and coupling change rate Δk _t defined in this paper are the key parameters in the process of coupling structure design and optimization. The combination of rounded rectangular spiral coil and splicing magnet core units is optimized as the coupling structure of the wireless charging system. Finally, the resonant wireless charging system prototype is being built and tested. The experimental results show that the load-independent and other characteristics of the implemented system are well correlated with the theoretical analysis and design.

Wireless power transfer (WPT) technology has become a popular solution to battery charging of mobile equipment. However, the variation of the load power will affect the transmission capacity of the system, which might make the electrical load cannot gain the required rated power and function improperly. Based on the analysis of power transmission characteristic and resonance state of WPT system, this paper adopts the simulated annealing (SA) method to track the maximum power point (MPP) of WPT in bifurcation state. The power tracking effectiveness of the proposed SA method is compared with that of the traditional maximum power point tracking method in WPT system based on perturbation and observation. The SA method performances under different parameters are assessed with consideration of the number of iterations needed for convergence and the convergence probability. Experimental validation of the maximum power tracking of WPT based on SA method is presented under different load conditions. Experimental results verify that the proposed SA method realizes the maximum power tracking when the WPT system works in the power bifurcation area, thus making full use of the inverter's VA capacity and approaching a unity power factor.

Wireless charging is the key technology to realize real autonomy of mobile robots. As the core part of wireless power transfer system, coupling mechanism including coupling coils and compensation topology is analyzed and optimized through simulations, to achieve stable and practical wireless charging suitable for ordinary robots. Multi-layer coil structure, especially double-layer coil is explored and selected to greatly enhance coupling performance, while shape of ferrite shielding goes through distributed optimization to guarantee coil fault tolerance and cost effectiveness. On the basis of optimized coils, primary compensation topology is analyzed to adopt composite LCL compensation, to stabilize operations of the primary side under variations of mutual inductance. Experimental results show the optimized system does make sense for wireless charging application for robots based on magnetic resonance coupling, to realize long-term autonomy of robots.

To solve the problem of short operating time of UAVs, this paper designs an asymmetric coupled wireless power transfer (WPT) system with optimized coupling structures and parameters, which effectively improves horizontal tolerance and performance for UAVs’ charging. Expressions of receiving power and transfer efficiency are derived to guide the design of parameters by modeling and analyzing the WPT systems. Structures and parameters of coupling coils are optimized to improve the quality factor and horizontal tolerance by simulations and comparison. System characteristics are further calculated and optimized with compensation topology. A prototype platform is implemented to verify the analysis and design, and experimental results show that it can achieve 64.87 W power transfer for UAVs with 57.94 % transfer efficiency, and the system is tolerant to horizontal misalignments of coupling coils. The analysis, design and implementation of asymmetric coupled WPT systems provides an important reference for the application of WPT technology in UAVs’ charging.

A loosely coupled inductive power transfer (IPT) system for industrial track applications has been researched in this paper. The IPT converter using primary Inductor-Capacitor-Inductor (LCL) network and secondary parallel-compensations is analyzed combined coil design for optimal operating efficiency. Accurate mathematical analytical model and expressions of self-inductance and mutual inductance are proposed to achieve coil parameters. Furthermore, the optimization process is performed combined with the proposed resonant compensations and coil parameters. The results are evaluated and discussed using finite element analysis (FEA). Finally, an experimental prototype is constructed to verify the proposed approach and the experimental results show that the optimization can be better applied to industrial track distributed IPT system.