| 摘要 |
PROBLEM TO BE SOLVED: To estimate the pole position through a simple means without requiring a pole position estimator. SOLUTION: In a permanent magnet type synchronous motor 51 controlled by a variable voltage and a variable frequency delivered from a power converter, and a controller for the permanent magnet type synchronous motor in machine units 11, 12, 13, 52 driven through the permanent magnet type synchronous motor, a brake 31 for holding stoppage of the machine units is released and when a motor torque generated by supplying a specified armature current is substantially balanced with a load torque regardless of the rotational position of the permanent magnet type synchronous motor, pole position phase of the permanent magnet type synchronous motor is estimated from the load torque and/or the armature current. |
