Prime mover systems including variable speed clutches for alternators and methods of controlling same

A method comprising:

• operating a prime mover system including a prime mover having an output shaft, an exhaust system that includes an aftertreatment system, an electric energy storage system, at least one alternator, and at least one variable speed clutch that engages the at least one alternator to the output shaft, wherein the variable speed clutch is operated at a nominal speed setting and at a plurality speed settings that are greater than the nominal speed setting and that are lower than the nominal speed setting;
• evaluating an operating parameter of the prime mover system;
• and
• controlling the at least one variable speed clutch from the nominal speed setting to one or more of the plurality of speed settings to vary a speed of the at least one alternator in response to the operating parameter of the prime mover system.

A method comprising:

• operating a prime mover system including a prime mover having an output shaft, an electric energy storage system, at least one alternator, and at least one variable speed clutch that engages the at least one alternator to the output shaft, the prime mover system including plug-in hybrid configuration with an internal combustion engine and an electric propulsion motor operable with electric energy from the energy storage system;
• evaluating an operating parameter of the prime mover system that is a desired charging speed of the energy storage system while plugged in;
• and
• controlling the at least one variable speed clutch to increase a speed of the at least one alternator to increase the charging speed in response a rapid charging speed and disengaging the at least one alternator from the output shaft with the variable speed clutch in response to a slow charging speed.

A method comprising:

• operating a prime mover system including a prime mover having an output shaft, an electric energy storage system, at least one alternator, and at least one variable speed clutch that engages the at least one alternator to the output shaft, the prime mover system including a plug-in hybrid configuration with an internal combustion engine and an electric propulsion motor operable with electric energy from the energy storage system, the prime mover system further including a heating-ventilation-air conditioning system;
• evaluating an operating parameter of the prime mover system that is a plugged-in status of the plug-in hybrid;
• and
• controlling the at least one variable speed clutch to disengage the at least one alternator from the output shaft with the variable speed clutch in response to the plug-in hybrid being plugged-in and charging.

A method comprising:

• operating a prime mover system including a prime mover having an output shaft, an aftertreatment system, at least one heater for the aftertreatment system, at least one electrically powered accessory, at least one alternator, and at least one variable speed clutch that engages the at least one alternator to the output shaft;
• evaluating a temperature condition of at least one of the prime mover and the aftertreatment system to be less than a temperature threshold;
• and
• controlling the at least one variable speed clutch to engage the at least one alternator in response to the temperature condition to operate the electric heater to increase the temperature of the aftertreatment system and determining the electric heater is inactive in order to control the at least one variable speed clutch to engage the at least one alternator to generate electrical power for the at least one electrically powered accessory.