| 摘要 |
PROBLEM TO BE SOLVED: To overcome such a problem that it is too large and costly to install discrete back-up power device for a plurality of motor drives running on inverters or to provide a large single back-up system to sequentially support those motors. SOLUTION: A back-up device 10 is provided. Switches 14-16 switch the inverters of the motor drives not in operation to the back-up system to run the motors 4-6 separately. The back-up sequence for the motors depends on the load conditions to minimize the capacity of the back-up system. |
