Impedance-Based Synchronization of Active Rectifier in Inductive Power Transfer Systems

Active rectification is a common option for improving efficiency and impedance matching in inductive power transfer systems. One of the technical challenges in active rectification is the synchronization of phase angle. In this work, the rectifier input impedance, which is calculated from the AC current and AC voltage, is used as the control objective during phase synchronization. When the impedance angle matches the target value, synchronization of phase is automatically fulfilled. The details of a PI-controller-based phase synchronization algorithm is introduced, and the PI coefficients are manually optimized. Experimental results demonstrate the good performance of the proposed phase synchronization method.