2023 journal article
Design of a Capacitive Wireless Power Transfer System With a Vertical Four-Plate Coupler for Minimum Stray Electric Field
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS, 11(5), 5486–5499.
Capacitive wireless power transfer (CPT) is the emerging technology of contactless power delivery outperforming the inductive method in some applications, such as small gap designs, when a metal object is present between the plates or when an inexpensive and lightweight solution is imperative. However, stray electric field confinement is one of the primary challenges regarding CPT practical implementation. Unlike in inductive wireless systems, where various passive and active forms of field cancellation or shaping exist, this is still an active research question in a CPT system, particularly for the more recent vertical four-plate coupler (V4PC). This research studies how the prohibited zone of the excessive field around a practical V4PC coupler can be minimized using an optimum design of compensation networks at the transmitter and receiver. After the stray field evaluation metrics are defined, the optimum design of LC and LCL compensation networks is derived and tested through simulations. Experiments on an 85-W CPT system with V4PC and LC – LC compensation were conducted, confirming the existence of the optimum design and reducing the prohibitive zone of the excessive field around the LC-compensated coupler by 25%.