| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in a conventional control device for a synchronous motor, that because the motor is placed into a free-run state by stopping a dynamic brake operation, the braking distance before stoppage is extended.SOLUTION: A control device for a synchronous motor of the present invention comprises: an allowable energy value acquisition unit for acquiring an allowable energy value in which a dynamic brake resistance can withstand, in order for the input terminals of the synchronous motor to be shorted when abnormality occurs; an inertia estimation unit for estimating the inertia of a driven object on the basis of a speed value fed back from the synchronous motor and a current value fed back from an amplifier and input to the synchronous motor; an allowable maximum speed calculation unit for calculating an allowable maximum speed value of the synchronous motor from the inertia and the allowable energy value; and a speed control unit for controlling the amplifier in order for the synchronous motor to be operated at a prescribed instruction speed, the control device being characterized in that the speed control unit acquires the allowable maximum speed value from the allowable maximum speed calculation unit and limits the instruction speed to below the allowable maximum speed value. |
