Wireless Charging Techniques and Converter Topologies for Light EVs, E-Bikes, E-Chairs and EScooters: A Review

Utility grid and distribution networks have experienced a high penetration of electric chargers into homes, public areas, and campuses due to the extensive increase of light Electric Vehicles (EVs) and similar low-power applications such as Electric-Bikes (E-Bikes), Electric Scooters (E-scooters) and Electric chairs (E-Chairs). Also, the flexibility and reliability of wireless power transfer (WPT) technology motivates researchers and designers toward wireless charging because the required power is low and compact chargers can be easily achieved. Although wireless chargers for EVs that need higher power and fast charging have been widely discussed in the literature, the focus on low-power charging applications and their detailed classifications has not been covered well. To fill this gap, this paper significantly shows a literature survey for wireless chargers for low-power applications. The essential techniques of these chargers and their converter/inverter topologies are summarized and compared with a special focus on charger architecture, coils specs, voltage and current stress, efficiency, component counts, and battery specs. Further, the control techniques and their impact on charging speed are intensively discussed. This review also outlines the standards and safety concerns of these types of wireless chargers. Finally, a recommendation based on the results of this review is given for future work.