No abstract

Conventional cabled seafloor observatories (CSOs) power in-situ instruments via wet-mated or dry-mated direct electrical contact (DEC) connectors to achieve long-term and real-time observation. However, the DEC connectors have high risks of water leakage and short circuits in power feeding, especially under high water pressure. This paper proposes a highly compatible underwater station based on inductive wireless power transfer (IPT) technology to address the above reliability issue. A novel energy transmitter with runway-structure coils is applied to the proposed underwater station to cover a sufficient power feeding area so that various in-situ equipment can be powered with desirable misalignment tolerance. The magnetic field distribution is analyzed by both derivation and finite element analysis (FEA) methods, and the principal parameters of the transmitter are further optimized and compared with both the mixed-integer sequential quadratic programming (MISQP) algorithm and the evolutionary algorithm (EA) for better performance. The same results show a reliable optimization process. The WPT circuit characteristics are also investigated to power different loads and improve the power transmission efficiency. The output power decreases, and the transmission efficiency rises and then decreases as the load increases. In addition, receivers with higher mutual inductance have better transmission performance. A prototype of the underwater station has been tested both in air and in water, and the experimental results have proven it can power multiple seafloor observation instruments stably and achieve compatibility requirements. The maximum output power of the station prototype for testing is 100 W, and the maximum overall transmission efficiency is 61%.

Autonomous underwater vehicles (AUVs) are important mobile equipment for ocean observation. Subsea docking stations are used to charge AUV batteries to increase their cruise duration. Here, a universal wireless charging platform with a novel transmitter is developed to address the issues of poor compatibility existing in conventional docking stations. In order to guarantee a sufficient charging area and reduce copper losses, the proposed transmitter is designed to have a bulged‐structure surrounding coil and a centre coil in coaxial. Moreover, the parameters of the transmitter that impact the magnetic flux density are analysed and optimized by non‐linear programming by Quadratic Lagrangian (NLPQL) algorithm to achieve a field with desirable intensity and uniformity. The characteristics of the circuits under single‐load and double‐load conditions have been tested in air and tank experiments. The results verify that the proposed platform achieves both the universality and misalignment tolerance requirements.