| 摘要 |
PROBLEM TO BE SOLVED: To eliminate hunting at an area near the target stop position at the time of stopping a synchronous motor to the constant position. SOLUTION: An apparatus for realizing stop at the constant position has a three-phase motor 4, a controller having a current control loop to control this three-phase synchronous motor 4 with a current element of the orthogonal (d) and (q) axes, a rotating angle detector 5 for detecting a rotating angle θfb of the three-phase synchronous motor 4, a current calculation unit which gives a d-axis current command Id* and a q-axis current command Iq* respectively based on a torque command Tref and a rotating angle θfb. The apparatus drives the synchronous motor in order to set a positional deviation Δθ between the rotating angle θfb of the three-phase synchronous motor 4 and the target stop position θref to zero. Further, the apparatus comprises a comparison means 12 for outputting an operation signal when a position deviation Δθ is less than the preset value Δθs as a result of comparison between the positional deviation Δθand present value Δθs, and a switching means SW1 for switching a d-axis current Id to zero based on the operation signal of the comparison means 12. |
