| 摘要 |
PROBLEM TO BE SOLVED: To uninterruptedly perform power supply changeover without protecting and stopping an inverter even in the state that a part between both power supplies is asynchronous when the power supply changeover of the inverter and commercial power supply is performed. SOLUTION: The uninterruptive power supply device has an excessive current control means 63 for outputting a gate operation signal when the judgment of a synchronous judging means 61 for judging a part between both alternating current voltage signals of the inverter 1 and the commercial power supply 7 synchronous and asynchronous is asynchronous, the output current of the inverter 1 exceeds a prescribed value and is excessive current, and a gate control means 24 for controlling the gate of a switching element constituting the inverter 1 so as to suppress excessive current by receiving the gate operation signal. |
