Electric continuously variable transmission and controls for operation of a heat engine in a closed-loop power-control mode

An electric continuously variable drive system, comprising:

• a plurality of ac motors;
• input means for receiving an operator command, said operator command being converted to a torque command for determining the torque output of said motors;
• an alternator for supplying electrical power to said ac motors via a rectifier and an inverter associated with each respective motor, said alternator being controlled by an alternator power command and operating in a closed-loop power mode within a normal operating range for said alternator;
• a heat engine for driving said alternator, said heat engine operating in a closed-loop power mode;
• heat engine control means for electronically controlling said heat engine via an injector duty cycle command or a throttle position command;
• torque feedback means for measuring actual torque produced by each of said ac motors and for deriving a total torque command therefrom;
• motor speed feedback means for measuring motor speed for each respective motor;
• heat engine speed feedback means for measuring heat engine speed;
• means for deriving a motor power command from said total torque command and the motor speed feedback from each of said motors and further for deriving a total motor power command therefrom;
• means for deriving a heat engine power command from said total motor power command;
• heat engine power computation means for computing actual heat engine power from said heat engine speed and said injector duty cycle command or said throttle position command;
• comparison means for comparing said heat engine power command to the actual heat engine power and generating a difference signal therefrom;
• and
• heat engine operating point command means for receiving said heat engine power command, said difference signal and said heat engine speed and providing an operating point signal to said heat engine control means to control said heat engine in order to minimize fuel usage and emissions thereby.

An electric continuously variable drive system for an electric drive, comprising:

• an ac motor;
• input means for receiving an operator command, said operator command being converted to a torque command for determining the torque output of said motor;
• an alternator for supplying electrical power to said ac motor via a rectifier and an inverter, said alternator being controlled by an alternator power command and operating in a closed-loop power mode within a normal operating range for said alternator;
• a heat engine for driving said alternator, said heat engine operating in a closed-loop power mode;
• heat engine control means for electronically controlling said heat engine via an injector duty cycle command or a throttle position command;
• torque feedback means for measuring actual torque produced by said ac motor;
• motor speed feedback means for measuring motor speed;
• heat engine speed feedback means for measuring heat engine speed;
• means for deriving a motor power command from said torque command and said motor speed;
• means for deriving a heat engine power command from said motor power command;
• heat engine power computation means for computing actual heat engine power from said heat engine speed and said injector duty cycle command or said throttle position command;
• comparison means for comparing said heat engine power command to the actual heat engine power and generating a difference signal therefrom;
• heat engine operating point command means for receiving said heat engine power command, said difference signal and said heat engine speed and providing an operating point signal to said heat engine control means to control said heat engine in order to minimize fuel usage and emissions thereby;
• and
• energy storage means for providing electrical energy to said electric continuously variable drive system for reducing peak power demands on said heat engine, said energy storage means recovering energy from said motor during regeneration.

An electric continuously variable drive system for an electric drive, comprising:

• a plurality of ac motors;
• input means for receiving an operator command, said operator command being converted to a torque command for determining the torque output of said motors;
• an alternator for supplying electrical power to said ac motors via a rectifier and an inverter associated with each respective motor, said alternator being controlled by an alternator power command and operating in a closed-loop power mode within a normal operating range for said alternator;
• a heat engine for driving said alternator, said heat engine operating in a closed-loop power mode;
• heat engine control means for electronically controlling said heat engine via an injector duty cycle command or a throttle position command;
• torque feedback means for measuring actual torque produced by each of said ac motors and for deriving a total torque command therefrom;
• motor speed feedback means for measuring motor speed for each respective motor;
• heat engine speed feedback means for measuring heat engine speed;
• means for deriving a motor power command from said total torque command and the motor speed feedback from each of said motors and further for deriving a total motor power command therefrom;
• means for deriving a heat engine power command from said total motor power command;
• heat engine power computation means for computing actual heat engine power from said heat engine speed and said injector duty cycle command or said throttle position command;
• comparison means for comparing said heat engine power command to the actual heat engine power and generating a difference signal therefrom;
• heat engine operating point command means for receiving said heat engine power command, said difference signal and said heat engine speed and providing an operating point signal to said heat engine control means to control said heat engine in order to minimize fuel usage and emissions thereby;
• and
• energy storage means for providing electrical energy to said electric continuously variable drive system for reducing peak power demands on said heat engine, said energy storage means recovering energy from said motors during regeneration.