Design of double-layer parallel printed spiral coil for Wireless Power Transfer applied to rotating equipment

Abstract Wireless power transfer (WPT) is a promising technology for remotely powering a wide variety of applications in rotating electronic devices. Although this method was introduced a long time ago, it still faces several challenges. The main challenge is that the traditional Litz coil cannot be fixed in high-speed rotating equipment, and the existing single-layer printed spiral coil has low quality factor. Therefore, to increase the coils’ quality factor and improve the transmission efficiency and output power of the system, a novel double-layer parallel coil model is proposed and compared with a conventional single-layer coil. Through experimental validations and simulation analysis, this study shows that, when the system frequency is 100 kHz and a double-layer parallel coil is employed, the quality factor of the coil is enhanced by 57.4 % compared to a single-layer coil. In the case of an input voltage of 8 V and a transmission distance of 10 mm, the output power of the double-double coil is increased by 1.65 W compared with the single-single coil, and the transmission efficiency is increased by 22.5 %, thereby realizing efficient WPT and providing reliable power transmission for sensors on rotating machinery such as helicopters and aero engines.