Universal Design Method of Load-Independent Constant Voltage and Constant Current Outputs for Capacitive Power Transfer System

In the field of wireless power transfer technology, capacitive power transfer (CPT) technology has received more and more attention due to its numerous advantages. Drones that are using lithium batteries as a power source require CPT systems to provide constant voltage (CV) and constant current (CC) outputs. This article proposes a universal design method of load-independent CV and CC outputs for CPT systems, making the design of CV and CC outputs more convenient and efficient, simplifying the process of configuring compensation network, optimizing the calculation of compensation elements parameters, and designing a system with high transmission efficiency in both CV and CC modes. Design and analysis methods of CV and CC outputs for CPT systems with arbitrary higher-order compensation networks are established based on fundamental compensation units. Besides, an optimized calculation method for parameters of compensation elements is given. An LCLC-LC compensated and an LCL-LCLC compensated CPT system are used as examples to describe the design and analysis process. An LCLC-LC compensated CPT prototype is built to verify the effectiveness and feasibility of the proposed method. The efficiencies of 88.43% at the CV frequency of 433 kHz and 82.59% at the CC frequency of 469 kHz have been achieved.