Patent ID: 7818111

Claim:
A motor control apparatus provided in a hybrid vehicle that has a motor and a phase changing device, and is driven by at least the motor or an internal combustion engine, the motor including a plurality of rotors each having a magnet piece, and the phase changing device changing a relative phase of each of the rotors by a fluid pressure of a working fluid, the motor control apparatus comprising: a displacement mechanism phase calculation unit is configured to calculate a reduced energy that is produced when a drive mode of the hybrid vehicle is shifted from a drive mode driven by the motor to a drive mode driven only by the internal combustion engine and if the phase of the motor is changed from a present phase to an arbitrary required phase, calculate a displacement energy that is produced when the present phase is changed to the arbitrary required phase, and compare the reduced energy and the displacement energy, and permits changing from the present phase to the required phase when it is determined that the reduced energy is greater than the displacement energy.