Patent attributes
An uninterrupted power supply apparatus includes a plurality of uninterrupted power supply modules each including a converter, a chopper, and an inverter, and a first control unit configured to output an voltage indication and phase information for controlling timing of switching operations of switching devices in the chopper and the inverter, wherein each of the uninterrupted power supply modules includes a second control unit that is configured to generate a first triangular carrier in synchronization with the phase information, to generate a second triangular carrier such that a phase of the second triangular carrier is synchronized with a phase of the first triangular carrier, the first triangular carrier being used with the voltage indication to control switching operations of the switching devices in the inverter, the second triangular carrier being used with the voltage indication to control switching operations of the switching devices in the chopper.