| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric motor drive device which can properly reconnect AC motors free-running at rotation speeds differing between groups and can restore them to a steady state in as short time as possible.SOLUTION: The electric motor drive device comprises: an inverter device 2; a plurality of branch switches 31, 32 and 33 which branch a plurality of AC motors into a plurality of motor groups 41, 42 and 43 so that they are separately supplied with power; reconnection control means 7 which exerts control to drive the AC motors again when the inverter device 2 is restored from abnormality; frequency detectors 71, 72 and 73 which are each connected to the output sides of the plurality of branch switches; and reconnection computation means 8 which computes a condition necessary for reconnection on the basis of the signals of the frequency detectors 71, 72 and 73 and gives the result of computation to the reconnection control means 7. When the inverter device 2 is restored from abnormality, the reconnection computation means 8 computes an inverter frequency condition at reconnection time for the inverter 2 not to be overloaded and a closing condition for the branch switches 31, 32 and 33 to be closed. |
