Evolution of Hybrid Inductive and Capacitive AC Links for Wireless EV Charging—A Comparative Overview

The inductive link in a wireless power transfer (WPT) system, fed by various high-frequency power converters with appropriate control strategies is widely accepted for medium power (<; 50 kW) and medium distance (100-200 mm) applications due to notable efficiencies (>95%) in static wireless charging scenarios. However, considering the dynamic wireless charging, the inductive link implementation for millions of kilometers is quite expensive due to the need for sophisticated resources. Therefore, relatively low-cost capacitive link, which initially focused on low power (<; 100 W), small distance (<; 10 mm) applications, has gained momentum and is explored for medium power (~3kW), medium distance (~100mm) applications. It has achieved a considerable dc-dc efficiency (>90%) and significant misalignment tolerance. This paper aims to find the significant roles played by inductive and capacitive ac link designs in static and dynamic expansion of wireless electric vehicle (EV) charging. Through a relative analysis, this paper emphasizes the need for mutual promotion of these ac links as a hybrid system in order to boost wireless EV charging technology.