| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce a torque error possibly occurring when executing flux weakening control. <P>SOLUTION: An axial error estimation part estimates an axial error that is a phase difference between a dq coordinate system and a different control coordinate system. A qm axis is a rotation axis whose orientation is identical with the orientation of an output current vector when realizing the maximum torque control. When realizing a flux weakening control, a target value θ<SB POS="POST">t</SB>of an axial error is set on the basis of a current for the flux weakening control so that the output current vector of a motor traces along a constant torque curve 311 in accordance with a torque instruction value. Forming a PLL causing the axial error to be identical with the target value θ<SB POS="POST">t</SB>will cause the end point of the output current vector V<SB POS="POST">323</SB>of the motor to be overlapped on the constant torque curve 311 (that is, the torque error between the output torque and torque instruction value to be zero). <P>COPYRIGHT: (C)2012,JPO&INPIT |
