Abstract: A marine power system including multiple of fuel cells, multiple of D C/AC converters and at least one propulsion motor. In the marine power system, each fuel cell of the multiple of fuel cells is connectable to an input of a DC/AC converter of the multiple of DC/AC converters and at least one group of multiple of DC/AC converters is connectable to the at least one propulsion motor to provide variable frequency and amplitude voltage to the at least one propulsion motor. Further, at least one of the multiple of DC/AC converters is connectable to a fixed frequency AC bus to provide voltage with a fixed frequency and amplitude to the fixed frequency AC bus.

Abstract: A fuel cell power system and a method of starting a fuel cell power system. The fuel cell power system includes a fuel cell system having one or more voltage outputs, one or more DC/DC converters each having an output and an input, the input being connectable to the voltage outputs of the fuel cell system, a DC voltage link connectable to the output of the one or more DC/DC converters, and a local load connectable to the DC voltage link. In the system, the local load is adapted to draw power from the fuel cell system to decrease the voltage of the fuel cell system.

Abstract: A marine power system including multiple of fuel cells, multiple of D C/AC converters and at least one propulsion motor. In the marine power system, each fuel cell of the multiple of fuel cells is connectable to an input of a DC/AC converter of the multiple of DC/AC converters and at least one group of multiple of DC/AC converters is connectable to the at least one propulsion motor to provide variable frequency and amplitude voltage to the at least one propulsion motor. Further, at least one of the multiple of DC/AC converters is connectable to a fixed frequency AC bus to provide voltage with a fixed frequency and amplitude to the fixed frequency AC bus.

Abstract: An electric power generation system and a method in an electric power generation system.

Abstract: An electric power generation system and a method in an electric power generation system.

Abstract: A ship is disclosed which can include a hull, at least one propulsion unit having a propulsion engine, transmission, at least one propeller connected via the transmission to the propulsion engine, and an oscillation sensor situated in a vicinity of the at least one propeller in order to sense cavitation of the at least one propeller. A control unit can control the propulsion engine, the oscillation sensor being connected to the control unit, whereby the output signal of the oscillation sensor is analyzed in the control unit to detect and indicate that a worse degree cavitation is emerging on a display unit at the navigation bridge and/or regulate the rotation speed and/or the power of the propulsion engine.

Abstract: An arrangement is disclosed for supplying propulsion power to a contra rotating propellers (CRP) propulsion system in a marine vessel, which arrangement can include a first propeller driven by a rotating power unit, and a second propeller driven by an AC motor. The second propeller can be rotated in an opposite direction relative to the first propeller, wherein an AC generator is driven by the rotating power unit and the AC generator is electrically connected to the AC motor. The rotation speed of the second propeller is between for example 95% and 150% of the rotation speed of the first propeller. The AC motor and the AC generator have the same electrical frequency. The pole number of the AC generator is from for example 2 to 40 and the pole number of the AC motor is from for example 2 to 40.

Abstract: An arrangement is disclosed for supplying electric power to a propulsion system of a marine vessel having a propeller motor, which is connected to an AC generator. The AC generator supplies electric energy to the propeller motor. The AC generator is rotated by a rotating power unit. A frequency converter is electrically connectable in parallel to the AC generator and the frequency converter supplies electric power from a second power unit.