Marine AC generator system and method

A method of operating an AC power generation system on a marine vessel, the method comprising:

• providing a marine generator configured to charge at least one battery, the at least one battery powering an inverter configured to provide AC electrical power on the marine vessel;
• providing a first current sensor configured to sense a current input to the at least one battery and a second current sensor configured to sense a current output from the at least one battery, wherein a load amount is determined based on a difference between the current input and the current output;
• presenting on a user interface user-selectable inputs to select at least one of a low speed mode and a high speed mode;
• receiving a user input selecting one of the low speed mode and the high speed mode via the user interface;
• controlling operation of the marine generator with a controller to charge the at least one battery based on a comparison of the load amount to the threshold load;
• wherein controlling operation of the marine generator with a controller includes operating the marine generator at a low RPM to charge the at least one battery during a predefined low noise period so as to minimize noise and to operating the marine generator at a high RPM to charge the at least one battery during a predefined maximum charge speed period so as to minimize charge time, wherein the predefined low noise period and the predefined maximum charge speed period are defined based on a preset time schedule and/or a user mode selection;
• based on the low speed mode selection, operating the marine generator at the low RPM so as to minimize noise;
• and
• based on the high speed mode selection, operating the marine generator at the high RPM so as to minimize charge time.

A marine AC generator system on a marine vessel, the system comprising:

• a marine generator driven by an internal combustion engine and configured to generate an AC current, wherein the marine generator is configured to operate in a plurality of operation modes each having a different engine RPM at which the engine is operated to charge the at least one battery;
• a rectifier configured to rectify the AC current to produce a DC current;
• at least one battery configured to be charged by the DC current;
• a battery powered inverter configured to be powered by the at least one battery and to generate a variable current output frequency such that AC electrical power is provided to a load when the marine generator is not running;
• a first current sensor configured to sense a current input to the at least one battery and a second current sensor configured to sense a current output from the at least one battery, wherein a load amount is determined based on a difference between the current input and current output;
• and
• a controller configured to control RPM of the marine generator in the plurality of operation modes and to start operation of the marine generator to charge the at least one battery when a state of charge of the at least one battery is less than a predetermined turn on threshold or based on a comparison of the load amount to a threshold load and to stop operation of the marine generator when the state of charge of the at least one battery reaches a predetermined turn off threshold, wherein the plurality of operation modes are engaged based on a preset time schedule and/or a user mode selection;
• wherein the turn on and turn off thresholds are varied based on the operation mode of the marine generator.