The Propulsion System of the 2000m Deep Submergence Research Vehicle

Abstract

The propulsion system of the 2,000m Deep Submergence Research Vehicle has been designed to enable the vehicle to have high maneuverability at low speed. It has a main propeller at its stern which is able to be rotated in horizontal plane, and a pair of auxiliary propellers at midship. The direction of the thrust of the auxiliary propellers can be changed horizontally and vertically. The model basin tests, which consisted of resistance and self-propulsion test, propeller open test and the observation of the flow field, were carried out and it was evident that it could get the required maximum speed of 3 kts. These propellers are directly driven by AC electric motors of oil-filled pressure compensated type. The jumbo-transistor inverters are adopted to control the revolutions of these motors. The method of control is by VVVF (Variable Voltage and Variable Frequency), using the pulse width modulation. These inverters are put in a titanium alloy pressure vessel. After the trial productions of AC motor and inverters were completed, several tests were carried out under the conditions of high pressure and normal atmospheric pressure. The adoption of the above-mentioned AC motors and inverters makes the electric system smaller in size and lighter and minimizes the electric power consumption.