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The use of wireless power transfer technology in unmanned aerial vehicle (UAV) systems is rapidly improving in different application areas. The main limitations of electric-powered UAVs are their charging range and stability in dynamic conditions. To solve these, this article proposes a hybrid control method based on dc-link and switched capacitor control with a fixed operating frequency. The dc-link voltage is regulated by the boost power factor correction converter to smoothen the output voltage, and the switched capacitor is used to dynamically compensate for self-inductance variations under dynamic coupling conditions. The output voltage stabilization and near-unity power factor of the input impedance can be achieved by applying the hybrid control method. Therefore, efficiency improvement can be achieved. Furthermore, the proposed control method can also be applied to systems with large coupling variations. To verify the proposed control method, a 500-W prototype was set up in the laboratory, and the experimental results proved that the control method could ensure a stable output voltage with horizontal and vertical offsets of 200 and 62 mm. respectively. Additionally, the results show that the maximum efficiency of the proposed control method is 91.9%, demonstrating that the proposed method effectively improves the efficiency. [ABSTRACT FROM AUTHOR]

Devices and the passive components in the single-phase impedance source network converter are sensitive to the double-line-frequency (DLF) pulsation. Previous research works have studied the power decoupling and the DLF equivalent model for the power pulsation suppression method. This paper explored the DLF transfer routes in the impedance source network. A comprehensive stress derivation of the passive components and switching devices are obtained for the suppression method enhancement and optimization. For the DLF passive suppression method, the explanation for the passive component volume issue is provided from the stress aspect. The component value solution space and corresponding design guidance are presented. For the DLF active suppression method (ASM), a buck-type dc-side ASM suppression method is employed and its optimization is demonstrated with the assistant circuit stress analysis. The total capacitor and inductor values get reduced by 77% and 25%, respectively. The corresponding pulsewidth modulation method implementation and the common-mode leakage current demonstration are also presented. The effectiveness of the theoretical analysis and optimization methods is verified by simulations and experiments. [ABSTRACT FROM AUTHOR]