An All-the-Time Synchronization Technique for 2.2 kW Bidirectional Inductive Power Transfer System

This paper proposes an all-the-time synchronization technique without the dual-side frequency difference and power oscillation. Compared to the traditional method such as average frequency tracking with non-all-the-time synchronization, no accuracy requirements of controller for PLL, phase calibration and complex auxiliary circuits are needed. Without additional phase calibration, only the zero cross detections (ZCDs) and external trigger by the DSP controller is required to synchronize the phase and frequency. Meanwhile, it is more effective and simple to control the value and direction of active power and reactive power by adjusting the delay of output from ZCDs to achieve phase shift control. Finally, experimental results based on a 2.2 kW platform are presented to verify the effectiveness and practicality of this technique.