Free Positioning Wireless Charging System Based on Tilted Long-Track Transmitting Coil Array

As an emerging technology, wireless power transfer (WPT) can be applied in many fields such as consumer electronics. Due to the limited charging area, the user experience of wireless charging for consumer electronics needs to be enhanced. Based on the tilted long-track transmitting coil array, this brief proposes a high-degree-of-freedom WPT system to achieve free positioning wireless charging when the receiver is placed horizontally or with a tilted angle on the charging plane. Using long-track transmitting coils can enlarge the charging area along the track direction. Using the transmitting coil array and supplying power via two adjacent transmitting coils when the receiver is placed in between the transmitting coils can enhance the charging area along the direction perpendicular to the track direction. Using the tilted transmitting coils can enable wireless charging when the consumer electronics are in use, normally in a tilted angle. The adopted LCC-S (inductor-capacitor-capacitor-series) topology facilitates wireless charging with a weak coupling. The proposed system can achieve free positioning wireless charging horizontally, based on a limited number of transmitting coils and no selection switches. The experimental results have validated the proposed WPT system.