Purpose/Aim
In recent years, wireless power transfer (WPT) technology has been applied to more and more fields, and underwater WPT is one of them. However, traditional dual-coil WPT system will face the contradiction between coupler parameters and transmission performance in underwater environment, such as energy transmission distance, transmission power and transmission efficiency. Therefore, an underwater domino WPT system is designed in this paper. By adding a trunk coil, the system has better comprehensive power transmission performance. Through simulation modeling, the influence of seawater on underwater domino WPT system is analyzed to verify the feasibility of the design.
Experimental/Modeling methods
Based on Maxwell’s equations, this paper deduces the influence of seawater medium on the eddy current loss and resonant offset of underwater WPT system, establishes the seawater medium equivalent model and applies it to domino system. In terms of simulation modeling, the simulation model of underwater domino WPT system is established and designed through ANSYS Maxwell, UG and other software. Then, the coil model and external circuit are combined into the whole system through Maxwell/Simplorer joint simulation to analyze and optimize the design.
Results/discussion
Aiming at reducing the eddy current loss in seawater medium, this paper deduces the seawater equivalent eddy current loss model and resonance offset model in domino system, and analyzes their influence and corresponding suppression measures. Based on the above theory, an underwater domino WPT system simulation model is designed through simulation modeling, its magnetic field distribution and transmission performance are analyzed, and its advantages are verified.
Conclusions
There are two conclusions in this paper. The first is that the eddy current loss in seawater will reduce the transmission power and energy transmission efficiency of underwater WPT system, and also produce resonance frequency offset. In addition, the domino WPT system can suppress the above problems to a certain extent and is suitable for WPT requirements in underwater environment.
 

Wireless charging,Numerical modeling