Research on Optimization of Horizontal Omnidirectional Misalignment Tolerance of WPT Based on Double D Coupler

Abstract

DD (Double D) coils have been researched and utilized due to their excellent misalignment tolerance. Here, a compound DD coupler sets for stationary wireless power chargers, which has significantly better anti-misalignment performance than single DD coupler in all directions, is proposed. The transmitting coils are composed of two parts of DD coils wound in opposite directions. Moreover, to obtain the low-level variation of mutual inductance between compound transmitting coils and receiving coils when offset occurs, a parameter optimization strategy of compensation coils is also proposed. With the properly designed parameters, the mutual inductance between transmitting and receiving coils could remain basically constant when misalignment occurs, which means that the efficiency and power remain relatively constant when offset occurs. Finally, both single DD coils and compound DD coils experimental prototypes are built to compare anti-misalignment ability performance. The results show that the proposed system is basically more stable and has a higher output power and more stable efficiency than that of unoptimized coupler during migration. In particular, with the employment of the antiparallel winding, the efficiency fluctuates from 85.5% to 85% when the 0.1-m offset in the X-axis and Y-axis occurs simultaneously. Moreover, the higher and basically more stable output power is also achieved.