A New Hybrid Magnetic Coupler in Inductive Power Transfer System for High Misalignment Tolerance

Abstract

Wireless charging has become increasingly popular in low and medium-power applications, such as motor-driven carriers, unmanned aerial vehicles, electric bicycles, and inspection robots. Nevertheless, pad misalignment can significantly affect the system performance, leading to higher losses and a reduction in the power output. Particularly in the all directions of anti-misalignment strategies, a greater number of inverters and compensations are necessitated, leading to increased system dimensions and heightened complexity. This article proposes a new hybrid coupler that only uses a bipolar pad as the secondary pad and a solenoid (S coil) with an added quadrature coil (Q coil) as the primary pad. We develop and test a 50W prototype in the laboratory. The size of the coupler is 355 mm $ \times 290$ mm. The experimental and simulation results demonstrate that when the distance between the transmitter and receiver is 60 mm, the transmission efficiency remains within a range of 72% to 90% for all directions of anti-misalignment, while the output voltage exhibits fluctuations within a margin of 10%. The results indicate that the coupler has a great potential for use in low and medium power applications, and can even be used in high-power equipment.

Keywords

• Inductive power transfer (IPT)
• magnetic coupler
• pad misalignment
• solenoid-quadrature coil