摘要 |
The controller of the synchronous motor of the present invention includes: an allowable energy value acquisition unit (4) which acquires an allowable energy value until which a dynamic brake resistor, which is for short-circuiting the input terminal of the synchronous motor at a time of failure, can bear; an inertia estimation unit (6) which estimates inertia of a driven object based on a speed value and an electric current value; an allowable maximum speed calculation unit (5) which calculates an allowable maximum speed value of the synchronous motor from the inertia and the allowable energy value; and a speed control unit (2) which controls the amplifier for operating the synchronous motor at a predetermined commanded speed, in which the speed control unit (2) acquires the allowable maximum speed value from the allowable maximum speed calculation unit (5), and limits the commanded speed to the allowable maximum speed value or lower. |