Load-Independent Dual-Frequency Constant-Current and Constant-Voltage Wireless Power Transfer System for Multiple Pickups

The wireless charging technique for multiple pickups under the same electromagnetic field is deemed a convenient, simple, and compatible power supply approach, which is undergoing exponential growth. However, some concerns are emerging against this background: 1) Different operating frequencies of various charging standards pose challenges to the design of impedance matching network; 2) The wireless charging system hardly realizes constant-current (CC) or constant-voltage (CV) output characteristics under various charging frequencies. Hence, this paper presents and proposes a load-independent dual-frequency compensation topology to realize CC of both resonant frequencies on the primary side. Meanwhile, by adopting the proposed hybrid compensation network on the pickup side, both CC and CV can be satisfied according to the demand for devices. Moreover, a communication-free method for controlling the hybrid compensation network is also introduced. Verification results will be given to testify the feasibility and effectiveness of the proposed system.