Car

摘要

PROBLEM TO BE SOLVED: To further properly perform changeover of shutdown control and zero-torque control by further accurately estimating an electromotive voltage.SOLUTION: When an electromotive voltage Vbe is higher than a high-voltage system voltage VH when a zero-torque command is issued to a motor, zero-torque control is performed to the motor (S220), and when a q-axis voltage command Vq* reaches the high-voltage system voltage VH or lower when the zero-torque control is performed, the zero-torque control is transited to shutdown control (S160). During the zero-torque control, an electromotive voltage constant Ke0 is estimated on the basis of the q-axis voltage command Vq* (S140), during the shutdown control, a rotor temperature Tro0 is estimated from the electromotive voltage constant Ke0 which is estimated in the zero-torque control immediately before transition, and the electromotive voltage Vbe is calculated by estimating an electromotive voltage constant Ke on the basis of the rotor temperature Tro0, a stator temperature Tst and lapse time t (S180 to S200).SELECTED DRAWING: Figure 4