Patent ID: 7463006

Claim:
A motor drive control device that controls a motor having three phases, wherein a waveform of a current or an induced voltage of the motor is a rectangular wave or a pseudo-rectangular wave having n-th (n=2, 3, 4, . . . ) harmonics, comprising: a d-q voltage calculating unit that calculates a voltage ed and a voltage eq, which are respectively d-axis and q-axis components of a counter-electromotive force; a d-axis command current calculating unit that calculates a current command value Idref that is a d-axis component of the current command value on the basis of a torque command value Tref of the motor, a base angular velocity ωb of the motor, and a detected mechanical angular velocity ωm of the motor, when the mechanical angular velocity ωm is higher than the base angular velocity ωb; a q-axis command current calculating unit that calculates a current command value Iqref, which is a q-axis component of a current command value, on the basis of the voltage ed, the voltage eq, and the current command value Idref; and a current control unit that controls currents of the motor on the basis of the current command value Idref and the current command value Iqref.