Design of a Highly Compatible Underwater Wireless Power Transfer Station for Seafloor Observation Equipment

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%.

Experimental Results and Analysis of Midrange Underwater Asymmetric Wireless Power Transfer

“…(5) The range of load voltages is between 5 V and 10 V, which can be used to charge batteries for small underwater submarines [43]. (6) The coil size used in [34] is similar to that used in this paper, but it is more focused on short-range transfer, and it resonates at 373 kHz, while the work in [44] was also carried out at midrange (like this paper), but with a smaller-sized coil that resonates at 570 kHz. It is concluded that the frequency that distinguishes between different transfer conditions in seawater and air is related to the size of the coil and the transfer distance.…”

“…Compared with the conventional charging method, wireless power transfer (WPT) technology is garnering increasing attention as a result of the discarding of the traditional wire bondage, making the charging power supply and charging equipment completely isolated, and better solving the problems of exposed wires, easily produced contact sparks, and poor mobility that exist in wired electrical power transfer [1][2][3][4][5][6][7]. It has been widely employed in electric vehicles [8,9], medical equipment, portable electronic devices, aerospace applications, and ocean-related applications.…”

Wireless Power Transfer for Unmanned Underwater Vehicles: Technologies, Challenges and Applications

“…These configuration are used to charge only one device and have the advantage of allowing a higher misalignment. Some of the recent studies on these configurations can be found in [226][227][228]. In [226], they achieved a power transfer of 884 W with a 94.3% efficiency, and in [227], a power transfer of 1.5 kW with an efficiency of 89.8%.…”

Exploring the depths: Advancing seabed research in marine and environment

“…Explorations in these areas have unveiled new species and remarkable biotechnological applications. Through the implementation of numerical simulations and laboratory experiments, researchers have unraveled the mechanics and dynamics of fluid flow and heat transfer within these ecosystems [9,10] . These insights illuminate the processes that sustain these extraordinary habitats, offering valuable lessons for sustainable management and utilization of marine resources.…”