Method for a serial driving mode of a motor vehicle

A method for serial operation of a motor vehicle (1) that includes a transmission (2), comprising:

• operating a first electric machine (3) of the transmission (2) as a motor for driving the motor vehicle (1);
• operating a second electric machine (4) of the transmission (2) as a generator;
• generating a change-over signal when a difference between a temperature of the first electric machine (3) and a temperature of the second electric machine (4) exceeds a threshold value;
• and
• after generation of the change-over signal, switching the first electric machine (3) from the operation as the motor to the operation as the generator, and switching the second electric machine (4) from the operation as the generator to the operation as the motor in order to drive the motor vehicle (1).

A method for serial operation of a motor vehicle (1) that includes a transmission (2), comprising:

• operating a first electric machine (3) of the transmission (2) as a motor for driving the motor vehicle (1);
• operating a second electric machine (4) of the transmission (2) as a generator;
• and
• after generation of a change-over signal, switching the first electric machine (3) from the operation as the motor to the operation as the generator, and switching the second electric machine (4) from the operation as the generator to the operation as the motor in order to drive the motor vehicle (1), the switching of the second electric machine (4) from the operation as the generator to the operation as the motor comprises in the following sequence
• carrying out a load reduction at an internal combustion engine (VM) and the second electric machine (4) in order to unload a first clutch (K2) of the transmission (2),
• disengaging the first clutch (K2),
• synchronizing a first shift element (B) of the transmission (2),
• engaging the first shift element (B) to form a driving connection between the second electric machine (4) and an axle differential (18),
• carrying out a load reduction at the first electric machine (3) and a load build-up at the second electric machine (4) in order to unload a second shift element (A) of the transmission (2),
• disengaging the second shift element (A),
• synchronizing a second clutch (K1),
• engaging the second clutch (K1) to form a driving connection between the internal combustion engine (VM) and the first electric machine (3), and
• carrying out a load build-up at the internal combustion engine (VM) and the first electric machine (3) such that the first electric machine (3) is operated as the generator.

A method for serial operation of a motor vehicle (1) that includes a transmission (2), comprising:

• operating a first electric machine (3) of the transmission (2) as a motor for driving the motor vehicle (1);
• operating a second electric machine (4) of the transmission (2) as a generator;
• after generation of a change-over signal, switching the first electric machine (3) from the operation as the motor to the operation as the generator, and switching the second electric machine (4) from the operation as the generator to the operation as the motor in order to drive the motor vehicle (1);
• generating a further change-over signal
• when a temperature of the second electric machine (4) exceeds a threshold value or
• when the temperature of the second electric machine (4) exceeds the threshold value, and a temperature of the first electric machine (3) falls below another threshold value;
• after generation of the further change-over signal, operating the first electric machine (3) as the motor, and operating the second electric machine (4) as the generator.

A method for serial operation of a motor vehicle (1) that includes a transmission (2), comprising:

• operating a first electric machine (3) of the transmission (2) as a motor for driving the motor vehicle (1);
• operating a second electric machine (4) of the transmission (2) as a generator;
• after generation of a change-over signal, switching the first electric machine (3) from the operation as the motor to the operation as the generator, and switching the second electric machine (4) from the operation as the generator to the operation as the motor in order to drive the motor vehicle (1);
• generating a further change-over signal when a difference between a temperature of the second electric machine (4) and a temperature of the first electric machine (3) exceeds a further threshold value;
• and
• after generation of the further change-over signal, operating the first electric machine (3) as the motor, and operating the second electric machine (4) as the generator.

A method for serial operation of a motor vehicle (1) that includes a transmission (2), comprising:

• operating a first electric machine (3) of the transmission (2) as a motor for driving the motor vehicle (1);
• operating a second electric machine (4) of the transmission (2) as a generator;
• and
• after generation of a change-over signal, switching the first electric machine (3) from the operation as the motor to the operation as the generator, and switching the second electric machine (4) from the operation as the generator to the operation as the motor in order to drive the motor vehicle (1);
• and
• after generation of a further change-over signal, operating the first electric machine (3) as the motor, and operating the second electric machine (4) as the generator, switching the first electric machine (3) from the operation as the generator to the operation as the motor comprises in the following sequence:
• carrying out a load reduction at an internal combustion engine (VM) and the first electric machine (3) in order to unload a second clutch (K1) of the transmission (2),
• disengaging the second clutch (K1),
• synchronizing a second shift element (A) of the transmission (2),
• engaging the second shift element (A) to form a driving connection between the first electric machine (3) and an axle differential (18),
• carrying out a load reduction at the second electric machine (4) and a load build-up at the first electric machine (3) in order to unload a first shift element (B) of the transmission (2),
• disengaging the first shift element (B),
• synchronizing a first clutch (K2),
• engaging the first clutch (K2) to form a driving connection between the internal combustion engine (VM) and the second electric machine (4), and
• carrying out a load build-up at the internal combustion engine (VM) and the second electric machine (4) such that the second electric machine (4) is operated as the generator.