Patent ID: 8773054

Claim:
A hybrid vehicle system, comprising: an inverter circuit having a switching element which converts a direct current into an alternate current; a motor for driving a vehicle which receives the alternate current to be driven; a resolver which detects a rotor rotation angle of the motor; a control circuit which controls a switching operation of the switching element based on information on the rotor rotation angle and a torque command value; an engine connected to the motor through a crankshaft; and a crankshaft sensor which detects the number of revolutions of the crankshaft, wherein, when abnormality of the resolver is detected, the control circuit estimates the rotor rotation angle based on a difference between the present number of revolutions of the crankshaft and the number of revolutions of the crankshaft, which is detected a specified time before, and performs motor control including a weak field control based on the estimated rotor rotation angle, and wherein the specified time is a short period during which the difference between the numbers of revolutions of the crankshaft is minute.