Patent ID: 8620508

Claim:
A hybrid vehicle driven by a power unit comprising: a first rotating machine comprising: a first rotor comprising a magnetic pole row arranged in a circumferential direction, wherein the magnetic pole row has a plurality magnetic poles and the adjacent magnetic poles have different polarities; a first stator disposed to face the first rotor in a radial direction and comprising an armature row comprising a plurality of armatures arranged in the circumferential direction, wherein a rotating magnetic field moving in the circumferential direction is generated by a change in magnetic poles generated by the plurality of armatures; and a second rotor disposed between the first rotor and the first stator and comprising a plurality of soft magnetic material elements arranged in the circumferential direction with a gap between the soft magnetic material elements, wherein the ratio between the number of magnetic poles generated by the armature row of the first stator, the number of magnetic poles of the magnetic pole row of the first rotor, the number of the soft magnetic material elements of the second rotor is set to 1:m:(1+m)/2 (mâ‰ 1), and one of the first rotor and the second rotor is connected to a drive shaft; a power engine, wherein an output shaft of the power engine is connected to the other of the first rotor and the second rotor; a second rotating machine configured to exchange a motive power with the drive shaft and to exchange an electric power with the first rotating machine; a capacitor configured to exchange an electric power between the first rotating machine and the second rotating machine; and a transformer that steps up a voltage when exchanging an electric power between the capacitor and at least one of the first rotating machine and the second rotating machine, the hybrid vehicle comprising: a voltage demand calculator that calculates a voltage demand required for each of the first rotating machine and the second rotating machine in accordance with an operating condition of the hybrid vehicle; a step-up execution determining unit that is configured to cause the transformer to step up the voltage, when at least one of the voltage demand of the first rotating machine and the voltage demand of the second rotating machine is higher than a first threshold value, wherein the first threshold value is set in accordance with an output voltage of the capacitor; and a controller that controls the transformer in accordance with the result determined by the step-up execution determining unit.