METHOD FOR CONTROLLING POWER SUPPLY SYSTEM

The present specification relates to an uninterruptible power supply device, an uninterruptible power supply system and a method for controlling the uninterruptible power supply system, and relates to a power supply device comprising a circuit breaker for switching connection to a power bus, thereby controlling the reception and supply of the power by opening and closing the circuit breaker according to various situations occurring in a system, a power supply system and a method for controlling the power supply system.