| 摘要 |
PROBLEM TO BE SOLVED: To extract desired torque with high precision all the time even immediately after switching a connection, by feedback-controlling exciting current and torque current in the inside of an induction motor so as to make the exciting inductance of parameter and secondary resistor independent. SOLUTION: Exciting current, for example, i1d in an induction motor and torque current i1q are detected from three instantaneous values iu to iw of motor current as a DC amount by three-phase two-phase converter 9 for converting into the two-phase detection value of a primary current detection value and an exciting current detection value of a three-phase induction motor 28. These are feedback-controlled independently against the respective ones of an exciting current command, for example, i1q* converted from a magnetic flux density command, and in a no-load condition with a small torque command, identification is conducted for exciting inductance M against the magnetic flux density command using the error amplifier output of the torque current. For secondary resistance also, identification is conducted using the error amplifier output of the torque current. By switching a correction identification value which is held based on the winding command, it is possible to use the identification value even immediately after connection switching. |
