DRIVING DEVICE FOR PROPELLING SHIP

PURPOSE:To prevent a prime mover and a generator which are accelerated by regenerative energy from exceeding an overspeed level and improve safety by previously lowering the speed of the prime mover by the amount of the speed increase of the prime mover corresponding to the quantity of the regenerative energy. CONSTITUTION:The field current of a generator 2 which is driven by a prime mover 1 to generate an alternating current is controlled so that the output voltage thereof is constant irrespective of the speed of the prime mover 1 by means of a field current controller 6. The AC output of the generator 2 is converted into optional voltage or frequency by a power converter 3, and an AC motor 4 is variably controlled by the output of the power converter 3 while driving the screw 5 of a ship by the AC motor 4. A control signal for the screw 5 is inputted from a speed controller 7 into the power converter 3. In this case, the rotating speed of the prime mover 1 is controlled by a speed controller 8 based on the reference speed of the prime mover 1 outputted from a speed reference generator 9.