| 摘要 |
PROBLEM TO BE SOLVED: To improve estimation accuracy of temperature of permanent magnets 10c, 10d by estimating change in motor constants by a variable mechanism with high accuracy even when the temperature of the permanent magnets 10c, 10d and magnetic flux density do not have one-to-one correspondence.SOLUTION: Permanent magnets 10c and 10d have variable portions 12c, 12d in which at least one of motor constants including magnetic flux density by the permanent magnet, induction voltage generated in an armature coil, magnetic permeability of the permanent magnets 10c, 10d and inductance of the armature coil in accordance with an operation condition of a motor. The variable portions 12c, 12d are formed at such a position that a predetermined harmonic content 2F of the motor increases or decreases in accordance with an amount of change in the motor constants. |
