Inductive Power Transfer System With Maximum Efficiency Tracking Control and Real-Time Mutual Inductance Estimation

To design simple and efficient inductive power transfer (IPT) systems, a minimum number of conversion stages and an effective maximum efficiency tracking (MET) are the primary design criteria. The MET control uses a fast mutual inductance estimation (MIE) algorithm to achieve fast tracking of the maximum efficiency point, especially when the variation of the gap distance and misalignment of the magnetic coupler are significant. The feedback control of the MET-MIE IPT system should be designed without a wireless communication channel to improve stability and robustness. In this article, a novel MET-MIE control strategy is proposed for achieving simplicity and high efficiency in IPT systems. Verifications are provided by simulations and experiments. It is shown that maximum efficiency can be tracked with less than 4% error in MIE under significant variation of the gap distance and misalignment of the magnetic coupler.