METHOD OF AUTOMATICALLY SWITCHING POWER FEED ROUTE TO INVERTER FROM COMMERCIAL POWER SUPPLY

摘要

PURPOSE: To automatically restoring an inverter drive system when it is stopped because of trouble, in an induction motor drive system where both an inverter and a commercial power supply are used. ;CONSTITUTION: When supplying power to an induction motor 5 is stopped due to trouble of an inverter in operation, just after the stop of the inverter or after a prescribed time from the stop, an electromagnetic contactor 4 is closed and an electromagnetic contactor 3 is opened in a conjugate manner by automatic operation, to create a commercial power supply route and cut off the inverter power supply route. Next, automatic resetting of an inverter trouble closing circuit is performed. When the resetting is successfully performed, after a prescribed time limit from the resetting closing the electromagnetic contactor 3 and opening the electromagnetic contactor 4 are performed in a conjugate manner, and restoring the inverter power supply route and cutting off the commercial power supply route are performed, so as to resume the inverter driving of the induction motor 5. When the resetting ends in failure, supply of commercial power to the induction motor 5 is continued, and an alarm of automatic trouble reset failure is issued to the outside.;COPYRIGHT: (C)1996,JPO