An Output Power Fluctuation Suppression Method of DWPT Systems Based on Dual-Receiver Coils and Voltage Doubler Rectifier

In dynamic wireless power transfer (DWPT) systems, the power oscillation phenomena caused by coupling fluctuation are always hard to avoid. Moreover, if the adjacent track coils are excited by different inverters without synchronized drive signals, there will be severe power oscillations due to the frequency difference between the track coil currents. To address these issues, this article proposes a novel DWPT system based on dual-receiver coils and the voltage doubler (VD) rectifier. Depending on whether the induced voltages of the two receiver coils are balanced, the rectifier will switch between full-bridge mode and VD mode with no extra controller to maintain the system output under different positions. By designing the dimensions of the coupler, the DWPT system can achieve excellent output stability while avoiding the oscillation caused by the frequency difference between the track coil currents. In addition, the operation characteristic, power divisions, and boundary conditions of each operation mode are clarified. Finally, a 2.2 m 220 V-800 W prototype is built. The experimental results show that even with the track current frequency difference, the output voltage fluctuation is limited to 3.4% during motion, and the system efficiency remains above 90.76% in the case of an 8 cm air gap.