| 摘要 |
PROBLEM TO BE SOLVED: To provide an inverter in which shock on a motor incident to alteration of frequency is suppressed sufficiently. SOLUTION: This inverter performs variable speed control of a motor by controlling the output frequency (f) of a power converter 1 toward a target frequency F delivered from a target frequency setting section 2 according to a preset variation pattern. A comparator 3D compares the target frequency F with an output frequency command Fc and only when they match each other, a switching signal S7 is generated in order to switch the contact (a) in a switch 3B to contact (b). A memory 3C is then updated with a new output frequency command Fc. When the control being executed according to the variation pattern is in transient state, the control is prohibited to start according to a variation pattern based on a new target frequency F, and thereby shock on the motor can be eliminated. |
