3.3kW Underwater Capacitive Power Transfer System for Electric Ship Charging Application

Among some charging solutions for electric ships, underwater capacitive power transfer is one of the promising technologies. This paper employs finite element simulations to design capacitive couplers. First, a four-plate coupler with insulation layers is analyzed, followed by an analysis of a six-plate coupler that considers the effect of electric field radiation. Moreover, the four-plate and six-plate couplers are compared. To validate the performance of the designed coupler, an experimental platform of an underwater capacitive power transfer system with a six-plate coupler and an M-M type compensation network is established. The coupler features a plate size of 200 mm and a transfer distance of 50 mm. In fresh water, the output power of the CPT system reaches 3.3 kW, while the DC-DC efficiency reaches 75.9%.