System and method of torque transmission using an electric energy conversion device

A method of adjusting torque output of a hybrid vehicle propulsion system, the hybrid vehicle propulsion system having a torque path including an internal combustion engine, a torque converter having an input and an output, the internal combustion engine coupled to the input of the torque converter, a multiple fixed-ratio transmission having an input and an output, the input of the multiple fixed-ratio transmission coupled to the output of the torque converter, and an electric energy conversion device located in the torque path downstream of the output of the multiple fixed-ratio transmission, the method comprising:

• adjusting a state of the torque converter to at least one of a locked and unlocked state upon a first condition;
• and
• adjusting the state of the torque converter to the at least one of a locked and unlocked state upon a second condition different from the first condition, wherein the first condition and the second condition differ based on torque output of the electric energy conversion device, said electric energy conversion device providing torque to vehicle wheels to meet driver demand during said second condition.

A method of controlling a hybrid vehicle propulsion system comprising:

• adjusting torque output of an electric energy conversion device located downstream of a multiple fixed-ratio transmission to reduce a transmission output torque load while providing torque to vehicle wheels to meet driver demand;
• and
• adjusting a shift schedule of the multiple fixed-ratio transmission responsive to the adjusted torque output of the electric energy conversion device while the electric energy conversion device provides torque to vehicle wheels to meet driver demand.