Drivsystem til skibe med en stor turboladet totakts stempelmotor med spildvarmegenvinding og fremgangsmåde til drift af driftsystemet

A marine propulsion system (1) with waste heat recovery, and main large two stoke turbocharged internal combustion engine (2) driving a propeller shaft (3) that is coupled to a ship propeller (4) . The waste heat recovery system (11) includes a turbine (18) and a generator (20) for generating electrical energy from waste heat of the main engine (2) for an electrical network (5) of the ship. A shaft generator/motor (10) is coupled to the propeller shaft (3) and connected electrically to the electrical network (5) of the ship. The shaft generator/motor (10) is configured to convert electrical energy from the electrical network (5) into mechanical energy for driving the propeller shaft (3) in a drive motor operation mode of the shaft generator/motor (10) and the shaft generator/motor (10) is configured to convert mechanical energy from the propeller shaft (3) into electric energy for the electrical network (5) in a generator operation mode of the shaft generator/motor (10). A controller (16) is operably connected to the shaft generator/motor (10) and the controller (12) is configured to control the frequency of the electrical network by adjusting the operation of the shaft generator/motor (10)