H5-Bridge-Based Bowl-Shape Wireless Charger for Multiple Loads

This article proposes a five-coil bowl-shape wireless charger based on an H5 bridge inverter. Inside the bowl, the five coils are customized and placed at different charging areas, which are able to offer two power channels for fast charging and multiload charging, respectively. A five-switch H5 bridge inverter is used to feed the optimal voltage through its multimode operation, which helps enhance the efficiency under various load conditions. The zero voltage switching is discussed for all the switches and achieved under the worst case, which is justified by the harmonic analysis. Finally, a 50-W experimental prototype is built and measured under various load conditions, and the peak charging efficiency is 88%.