Single-Switch Wireless-Power-Transfer Circuit With P-CLC Compensation Network Used for Battery Charging

At present, most of the analyses or studies about wireless power transfer (WPT) with the load-independent characteristics of constant current output (CCO) and constant voltage output (CVO) are carried out based on full-bridge topologies. The study about single-switch circuits used in wireless charging is infrequent. However, compared with full-bridge topologies, the structure and the control strategy of single-switch WPT circuit are simple and avoid the shoot-through problem, which makes it more advantageous in reliability and cost. In this article, a single-switch WPT circuit with P-CLC compensation network is proposed to realize CCO and CVO at two different frequencies f(CC) and f(CV), respectively. Compared with hybrid compensation, this switching method from CCO to CVO does not require extra mode switches and corresponding control circuits. Moreover, the transfer gain does not rely on the transformer parameters, and more parameters' design freedom can be realized. The analysis of the P-CLC compensation network illustrates that the proposed charging circuit could have a long transmission distance in low frequency. The few passive devices are used in this circuit for higher efficiency and lower cost. Finally, the simulation and the experimental verification are carried out to verify the superiority of the proposed circuit.