| 摘要 |
PURPOSE:To shocklessly switch to an inverter operation without causing a plurality of AC motors to operate in a regenerative state from a commercial power source drive by following up the decelerating speed to the minimum rotating frequency of the AC motors at free-running time. CONSTITUTION:An inverter frequency command for a common inverter 8 for a plurality of AC motors is followed to the rotating frequency of an AC motor having the minimum frequency command at the free-running time such as an induction motor 2A. Thus, a plurality of AC motors 2A, 2B can be shocklessly switched to an inverter operation due to an inverter 8 without causing the motors to operate in a regenerative state from a commercial power source drive. |
