Electromechanically controlled aircraft power transmission system

An electromechanically controlled aircraft power transmission system, comprising:

• a first planetary gear set having a gear ratio that is variable;
• a first gas turbine engine having a first output shaft coupled to the first planetary gear set;
• a first electric machine coupled to the first planetary gear set and configured to rotate at a rotational speed, the rotational speed of the first electric machine being used to vary the gear ratio of the first planetary gear set;
• a second planetary gear set having a gear ratio that is variable;
• a second gas turbine engine having second output shaft coupled to the second planetary gear set;
• a second electric machine coupled to the second planetary gear set and configured to rotate at a rotational speed, the rotational speed of the second electric machine being used to vary the gear ratio of the second planetary gear set;
• a propulsor shaft coupled to the first and second planetary gear sets;
• at least one propulsor coupled to the propulsor shaft;
• and
• control logic in operable communication with at least the first and second electric machines and the first and second gas turbine engines, the control logic configured to selectively control operation of the system in at least a start mode, a low-power mode, an intermediate-power mode, and a high-power mode.

An electromechanically controlled aircraft power transmission system, comprising:

• a first planetary gear set having a gear ratio that is variable;
• a first gas turbine engine having a first output shaft coupled to the first planetary gear set;
• and
• a first electric machine coupled to the first planetary gear set and configured to rotate at a rotational speed, the rotational speed of the electric machine being used to vary the gear ratio of the first planetary gear set;
• a second planetary gear set having a gear ratio that is variable;
• a second gas turbine engine having a second output shaft coupled to the second planetary gear set;
• and
• a second electric machine coupled to the second planetary gear set and configured to rotate at a rotational speed, the rotational speed of the second electric machine being used to vary the gear ratio of the second planetary gear set.