MARINE POWER SYSTEM

PROBLEM TO BE SOLVED: To attain enhancement of fuel economy while maintaining a target rotary speed even when influence by disturbance is large in a marine power system using PID control of a rotary speed base for fuel feeding. SOLUTION: A motor/generator 12 is connected to a crankshaft of a main machine 11. A rotary speed sensor 16 is provided on a main shaft 15 for connecting the main machine 11 to a propeller 13. PID control for fuel feeding is performed such that rotation of the main machine 11 is maintained to the target rotary speed based on the actual rotary speed of the main machine 11 detected by the rotary speed sensor 16. In a controller 19, excess or lack of main machine torque is determined from difference of the target rotary speed and the actual rotary speed. When the main machine torque is sufficient, an inverter/converter 17 is controlled to charge regenerative energy of the motor/generator 12 to a battery 18. When the main machine torque is insufficient, the motor/generator 12 is driven as a motor to perform assist. COPYRIGHT: (C)2011,JPO&INPIT