| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a magnetic pole position estimator for an electric motor, capable of preventing an increase in estimation error in estimating a magnetic pole position while scaling down the electric motor and enhancing output. <P>SOLUTION: The magnetic pole position estimator 10 for an electric motor includes: a magnetic pole position error estimating section 46 for estimating a phase difference Δθe of a γδ coordinate system for a dq coordinate system by utilizing the fact that an induction voltage generated by the motor 11 changes depending on a rotation speed; a rotation speed-magnetic pole position operating section 47 for operating a magnetic pole position estimation value θe from the phase difference Δθe; and a command current generating section 42 for changing a current command value into a value not less than a predetermined value when the current command value is less than the predetermined value in a result of determination for determining whether or not the current command value for the actual value of the motor 11 is less than the predetermined value, and maintaining the torque of the motor 11 at non-changing before and after the change of the current command value. <P>COPYRIGHT: (C)2010,JPO&INPIT |
