US 12,334,748 B2
Wireless battery charging system and method for battery charging and handshaking
Shu Yuen Ron Hui, Hong Kong (CN); and Yun Yang, Hong Kong (CN)
Assigned to The University of Hong Kong, Hong Kong (CN)
Appl. No. 17/754,244
Filed by THE UNIVERSITY OF HONG KONG, Hong Kong (CN)
PCT Filed Sep. 21, 2020, PCT No. PCT/CN2020/116514
§ 371(c)(1), (2) Date Mar. 28, 2022,
PCT Pub. No. WO2021/057658, PCT Pub. Date Apr. 1, 2021.
Claims priority of provisional application 62/906,180, filed on Sep. 26, 2019.
Prior Publication US 2022/0368160 A1, Nov. 17, 2022
Int. Cl. H02J 7/00 (2006.01); H02J 50/12 (2016.01); H02J 50/80 (2016.01)
CPC H02J 50/12 (2016.02) [H02J 7/0048 (2020.01); H02J 7/005 (2020.01); H02J 7/007182 (2020.01); H02J 50/80 (2016.02)] 13 Claims
OG exemplary drawing
 
1. A wireless charging system for wirelessly charging a battery, the system comprising:
a transmitter circuit comprising a power inverter used for driving a primary coil connected in series with a first resonant capacitor;
a receiver circuit comprising:
a secondary coil connected in series with a second resonant capacitor and a diode rectifier, an output of the diode rectifier being arranged to drive the battery directly without using an extra battery charging circuit to select a constant-current (CC) charging mode or a constant-voltage (CV) charging mode to charge the battery; and
a bidirectional switch having a dual function of charging the battery and handshaking with the transmitter circuit;
a transmitter controller configured to control the power inverter to switch at a constant and high frequency during normal wireless power transfer, and further configured to receive information generated from switching actions of the bidirectional switch of the receiver circuit during handshaking; and
a receiver controller configured to:
control the receiver circuit to switch at a constant and high frequency during normal wireless power transfer, and to switch at a low frequency to generate the information during a handshaking process;
compare a battery voltage (VBAT) with a battery voltage threshold (VOREG) and a battery charging current (IBAT) with a charging current reference (IBULK) so as to automatically select the CC charging mode or the CV charging mode; and
configure the receiver circuit to switch at the same constant and high frequency with the transmitter circuit during a battery charging process.