Investigation of a Synchronized Current Scale-Down Drive for the Maritime Magnetohydrodynamic Engine

The new frontier maritime magnetohydrodynamic (MHD) engine drive generates the fields of magnetic and electric to accelerate seawater inside the engine duct. The dc system is overwhelmed by the ac for no explosive and poison gases emission. The proposed power circuit applies a transformer to provide a new drive design for the ac system, by reallocating the field generation currents for propulsion. The excitation current for magnetic field generation now is higher in the primary side of transformer and thus to decrease the current flowing the liquid that drew plenty of the conduction loss in previous ac MHD drive in series-resonant design. To conduct the high-frequency ac to mitigate the gas emission and the phase difference between the fields, three resonant tanks are deployed, constructing a resonant circuit for high circuitry efficiency operation. This article starts from introducing the concept of maritime MHD engine and the research fundamental. The comparison to the conventional ac MHD engine drive stresses its advantage. A steady-state analysis elaborates that the proposed topology and design consideration highlights the optimal design to the turn ratio and engine duct design. The electrical-fluid experiment and the concept verified converter will be demonstrated with the 82% converter efficiency at 470 W, maximum 92% efficiency to back the validity.