Analysis of Compensation Topology with Constant-voltage/Current Output for Multiple Loads Capacitive Power Transfer System

As the main effective method of Wireless Power Transfer (WPT), Capacitive Power Transfer (CPT) has received extensive attention recently. For a CPT system, compensation topology is significant in improving system transfer power and controlling output characteristics. While the current research on multiple CPT systems only focus on the specific circuit, lacking systematic study on constant-voltage (CV) or constant-current (CC) output. This paper studies a general compensation topology model of a multiload CPT system based on CV and CC output characteristics. First, the general circuit model of primary and secondary compensation topology based on a T-type or Π-type circuit is constructed with the coupler’s simplified induced current source (ICS) model. A universal design method of the multiload CPT system is given. Then, according to the proposed theory, a multiload CPT system based on double-sided LCLC compensation topology is analyzed, achieving CC output, maximum coupler transfer power and zero phase angle between input voltage and input current. Lastly, an experimental setup of double loads CPT system with 500W&500W is carried out. When load resistance changes from 50 ohms to 100 ohms, maximum change rate of output current is 8.4%, with rated output current of 2.5 A.