A Multiple-Gain-Reconfigurable-Rectifier-Based IPT System for Battery Multistage Constant-Current High-Efficiency Wireless Charging

Inductive power transfer (IPT) technology is widely used for battery charging, whereas trickle charging is necessary for precharging a deeply discharged battery to prolong its lifetime. However, the trickle charging current is much less than the rated charging current. This leads to a challenge for IPT systems to achieve trickle charging and high transmission efficiency as well. In this article, a multiple-gain-reconfigurable-rectifier (MGRR)-based IPT system is proposed for the battery multiple stage constant-current (MSCC) high-efficiency wireless charging, especially for the deeply discharged battery MSCC high-efficiency wireless charging. With the MGRR, the IPT system can theoretically achieve 1.0, 0.5, 0.25, and 0.125 times of the rated output. Thus, trickle charging can be realized without a complicated control scheme. Calculation analysis shows that the proposed IPT system can simultaneously satisfy the battery charging requirements and achieve a near impedance matching for the high transmission efficiency. Finally, a 164-W prototype is built to validate the performance of the system. Experimental results show that the MGRR-based IPT system can effectively charge a deeply discharged battery with a high transmission efficiency as the efficiency in the entire charging process ranges from 89.4% to 93.7%.