Modeling wireless power transfer in marine environment via integrated electromagnetic field and circuit analysis

Abstract

In the marine environment, wireless power transfer faces significant eddy current effects due to the high electrical conductivity of seawater, making traditional modeling in the air environment inapplicable. In order to understand the effect of seawater on wireless power transfer, a circuit model whose key electric parameters are determined from electromagnetic field theory is proposed for series–parallel topological wireless power transfer in seawater. Firstly, the complex mutual inductance and complex self-inductance of the circuit model are calculated from in depth analysis of electromagnetic fields model of wireless power transfer under seawater. Subsequently, these parameters are incorporated into an equivalent circuit model, which contributes to more accurate circuit calculations and ensures the completeness and accuracy of the model. To validate the proposed model, a seawater wireless power transfer system with a 22.5 cm coil outer diameter and a 460 kHz resonant frequency is designed, and implemented. Its complex mutual inductance, complex self-inductance, load voltages and transfer efficiencies are calculated and then measured experimentally. Three methods were used to verify the complex mutual inductance and complex self-inductance: LCR method, open circuit method on the secondary side and simulation. While the load voltage and transmission efficiency are verified experimentally. The obtained theoretical calculations, electromagnetic simulations and experimental results are in good agreement. Through integration of electromagnetic field analysis and circuit analysis, the modeling of wireless power transfer is transformed from the traditional dependence on external excitation sources to a more autonomous and endogenous approach.