Achieving maximum power transfer of inductively coupled wireless power transfer system based on dynamic tuning control

As an emerging research field, inductively coupled wireless power transfer (ICWPT) technology has attracted wide spread attention recently. In this paper, the maximum power transfer performances of four basic topologies labeled as SS, SP, PS and PP are investigated. By modeling the equivalent circuits of these topologies in high frequency (HF), the primary resonance compensation capacitances for maximum power transfer capability are deduced. It is found that these capacitances fluctuate with load resistance change, which is disadvantageous to SP, PS and PP topologies and an obstacle to their practical applications as well. To solve this problem, a phase controlled inductor circuit is proposed. By adjusting the triggering angle, the real-time dynamic tuning control can be achieved to guarantee maximum power transfer. Finally, simulations and experiments show that the proposed method is of great effectiveness and reliability to solve the issue of resonance compensation capacitance fluctuation with load change and to guarantee the flexible applications of all topologies.