A power combining apparatus for a hybrid electric vehicle comprises a planetary gear set comprising a sun gear, a ring gear connected to an output shaft, a plurality of planet gears, and a carrier assembly rotatably supporting the plurality of planet gears journaled with the sun and ring gears. A torque transmitting arrangement is coupled to the sun gear and to the shaft of the variable power source for influencing rotation of the sun gear according to the rotation of the variable power supply shaft for causing rotation of the sun gear, thereby influencing rotation of the ring gear and the output shaft. The carrier assembly of the planetary gear arrangement is selectively connectable to the constant power source for selectively influencing rotation of the carrier assembly of the planetary gears and the ring gear, to thereby influence rotation of the output shaft.