| 摘要 |
PROBLEM TO BE SOLVED: To prevent tripping of a motor and continue its operation without causing damages to the motor or machines by, if it is predicted that the speed will be reduced abruptly, lowering the current target value given to the motor to prevent produced torque from exceeding an allowable value. SOLUTION: A current regulator 30 calculates a target voltage Vt to match an actual current Ia, detected through a current converter 28 with a target current It' outputted from a current limiter 26. The result of calculation is inputted to a power converter 34 via a gate pulse generator 32, and a motor terminal voltage V as a target is produced. Such a side guide drive device 20 is further provided with a load torque estimator 40, which estimates a load torque from the produced torque and speed of a motor 14 and a current target interrupter 42, which when the load torque estimated by the load torque estimator 40 exceeds a prescribed value, interrupts the target current It' inputted to the current regulator 30 and to set it to zero. |
