A coil structure that is compatible with the structure of the autonomous underwater vehicles (AUVs) and preventing the rotational misalignment is proposed for stabilizing the output power of a wireless power transfer (WPT) system. The transmitting coil and the receiving coil are wound on the structure of the energy base station and the AUV in a spiral tube type, respectively. This arrangement not only guarantees a constant mutual inductance when the AUV rotates, but it also maintains the efficient transmission of energy when the receiving coil is conformal with the AUV by optimizing the size of the magnetic core and the distance between the coil and the metal structure. The performance of the proposed coil structure is experimentally evaluated by building an inductor–capacitor–capacitor series (LCC-S)-compensated WPT prototype. It was found that the system can stably deliver a 2 kW power with a dc–dc efficiency of 92.7%.

It is usually necessary but difficult to achieve reliable communication between the primary side and pick-up side in the wireless power transfer (WPT) system due to magnetic interferences. In this paper, a novel parallel transmission method for wireless power and data is proposed, which is based on the frequency shift keying (FSK) modulation and demodulation. The data are transmitted by changing the working frequency of the inverter and then demodulated based on the phase-locked loop (PLL) technology. In this way, the signal before the rectifier circuit for the data demodulation can overcome the influence of power transmission on the data transmission. Finally, a 426 W prototype has been built to verify the effectiveness of the proposed transmission method. The experimental results showed that when the output power changed from tens of watts to hundreds of watts, the data transmission was capable of achieving a stable transmission with a 10 kbps baud rate.