POWER TRANSMISSION SYSTEM OF HYBRID ELECTRIC VEHICLE

A power transmission apparatus of a hybrid electric vehicle may include an input shaft receiving an engine torque output from an engine, an output shaft disposed at a same axis with the input shaft and outputting a shifted torque, first and second motor/generators, a first shifting section including a first planetary gear set, outputting a rotation speed from the input shaft as inputted or increased, or forming an adjusted torque from the engine torque and torques of the first and second motor/generators, and outputting the adjusted torque, and a second shifting section including a compound planetary gear set formed as a combination of second and third planetary gear sets and outputting a shifted torque at least three stages from a torque received from the first shifting section to the output shaft.